April 17, 2014, 11:31:25 PM

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Messages - jrista

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1
The notion that IS is unnecessary for focal lengths below 85mm was true.

What a load of pretentious, unmitigated, hypothetical sh!t.

Um, dude, seriously...you did see that I used the word "WAS", right?

WAS true. Not IS true. WAS true.

Chill. Sheesh.

Well I am using a camera with the same pixel pitch as a 10D, so if it is true today with my camera it was true back in Feb 2003 when the 10D came out. Your comment is completely, patently, and demonstrably ridiculous.

Until you show me full size versions of those images you shared, which appear to be quite sharp to me, that prove they are soft and needed IS (vs. say better focus), I'm sorry but I have to disagree tat it is "completely, patently, and demonstrably ridiculous." I've shot enough with a 50/1.4 to know that my shutter speed is most often well above the 1/focalLength and even above the 1/focalLength*2 baselines to produce shake-free shots except in more extreme circumstances (such as your second photo, however that would usually be where you jack up the ISO to compensate.)

If we were talking about an 85mm f/4 or even f/2.8 lens, I would completely agree with you...but 85mm lenses are f/1.8 or faster, 50mm lenses are usually f/1.4, and most frequently used at their faster apertures. Additionally, with wider fields, it takes more camera movement to result in meaningful motion of image detail at the pixel level, so blur from camera shake becomes less and less likely the shorter the lens.

And what's with the hostility? Wrong side of the bed day today or something?

2
The notion that IS is unnecessary for focal lengths below 85mm was true.

What a load of pretentious, unmitigated, hypothetical sh!t.

Um, dude, seriously...you did see that I used the word "WAS", right?

WAS true. Not IS true. WAS true.

I also said that the notion would become increasingly untrue...indicating that it is untrue now.

In other words...I agree with you. Back in the days of 10µm pixels (mid 2000s), I think IS with a 50mm or 35mm wouldn't have been nearly as useful as it would be today.

Chill. Sheesh.

3
EOS Bodies / Re: 1d IV vs. 7D II
« on: Today at 10:01:35 PM »
Everything I've said about FF vs. APS-C applies to APS-H vs. APS-C. It's sensor area that matters, so from a sensor IQ standpoint, the 1D IV wins.

Is it also true for an older sensor tech. vs a newer (future) sensor. I mean, is it theoretically impossible for an APS-C sensor to gather as much light as an APS-H sensor of the past? Not a rhetorical question, I am actually curious to know.
[for example, I know it is theoretically impossible for a future APS-C sensor to compete with the 6D, for example. Pi had proved that semi-mathematically.]

The 1D IV APS-H sensor was very good. It's one of Canon's better sensors. It has higher Q.E. than the 7D sensor, and is 1.6x larger. The 7D II would need to improve in Q.E. by 60%...or in other words, it would literally need to convert every single photon to charge in the photodiode, to perform as well as the 1D IV. Technological improvements can be made, but there is still that pesky problem of needing to convert more light than actually exists.

I think the 7D II could perform as well as the 1D IV if Canon managed to pack a hell of a lot of innovation into the new sensor. I mean, they would have to be really cutting edge, maybe even invent some new techniques to reducing read noise and improving sensor Q.E., and probably employ some kind of thermoelectric cooling (which in turn would require some kind of innovation in battery or power source to supply the increase in power needs). It's possible...but were talking REALLY cutting edge sensor technology. Cutting edge in a way that would have to blow away Sony's sensor tech. The 1D IV isn't that old of a sensor...a lot newer than the 7D sensor. Canon is barely on the map when it comes to CMOS Image Sensor (CIS) patents and innovation...they have had a few patents published in the last couple years, but Sony, Aptina, and a bunch of other manufacturers are running circles around Canon's sensor tech (sadly.)

So, in light of that...I'll leave it to you: Do you think the 7D II can perform better than the 1D IV?

And no, everything doesn't apply. FF is a technology Canon is continuing. So, for every APS-C there will be an FF counterpart (don't take that literally, I mean around the same time). APS-H on the other hand is dead. So for any new technology APS-C takes advantage of, APS-H has no new cards to play.

Heh, well, that's an interesting argument. Again, the APS-H from the 1D IV is not that old. Canon is not innovating that much on the sensor front (although they ARE a very highly innovative company at large, especially in optics.) Technological improvements that can be made in silicon and with CMOS fabrication are becoming harder and harder to discover and produce, so the next decade is likely to see less significant improvement over the same 10-year span as we saw from 2003-2013. Sure, assuming APS-H is truly dead (it's a technology Canon owns, and unused technology is wasted technology...I still think Canon will find ways of employing APS-H in the future, although I do suspect that it will either be in mirrorless or video cameras, rather than DSLRs.)

I think it would be very difficult for the 7D II to beat the 1D IV. At best, Canon might achieve parity, and some non-sensor features might be better (i.e. better AF system), but I generally don't think IQ will be better.

As I said, I defer to your greater knowledge to this answer. I personally felt Canon will replace the discontinued smaller sensor in high end body for those who want reach, pure and simple (not unlike yourself I am sure). Of course, now they get to sell longer lenses, hence more profit :)

Reach is really just a matter of pixel size. That is more of a happy side-effect of smaller sensors, than something that is out of reach of larger sensors. Canon could create a reach-monster if they release a Big MP FF camera with 4µm pixels. I think many people would get one just because of the versatility...reach and sensor size, best of all worlds...despite the frame rate (which is likely to be slower rather than faster.)

I myself am moving more towards full frame. I'll be picking up a 5D III in the coming months, and I highly expect my 7D to either be sold, or at least take a distant back seat. I already have the necessary glass...the 600/4 II is versatile enough with 1.4x (840mm) and 2x (1200mm) teleconverters. I was sad to see APS-H go...but I do have hope for it. I really hope to see it in an EOS-M one of these days. I think Canon could put out a large sensor mirrorless that can give good ol' Sony a run for their money if they would bring APS-H back into the fold.

4
Wonder if this lens will be eligible for Sigma's "mount conversion" service?

I'm surprised that so far nobody has said DxO's results are meaningless because they don't represent bokeh in their tests results anywhere! But at least the first post on this thread doesn't disappoint with the expected putting down of DxO.

When DxO get a Nikon mount copy of this lens, I think we'll see a much better representation of its capabilities. In at least one score, the "megapixel" thing, the scores are obviously limited to what Canon cameras can provide.

Compared to the 50/1.2L

NameCanon 50/1.2LSigma 50/1.4A
Sharpness1421
Transmission1.4TStop1.7TStop
Distortion0.4%0.1%
Vignetting-2.4EV-1.5EV
Chr Aberration20µm6µm


Wow, that's about as cherry picked and biased a comparison as I've ever seen. Do you even try to be objective?

Here is a more reasonable comparison:



However, this is highly skewed, because DXO uses their T-stops "measure" to determine what the "best" aperture is...and they chose f/1.2 on the 50mm as it's "best". That is about as close to the WORST aperture the 50/1.2 has...it gets far sharper and eliminates a ton of CA and vignetting when you stop down a bit. I would have chosen f/1.4 or f/1.8, both of which are definitely better than f/1.2 on the 50L, however in all their great and wonderful BIAS, DXO has conveniently not offered those as options.

When I choose f/2.8 for the Sigma, Otus, and 50L, the sharpness plots norm up quite nicely. The falloff in the corners of the 50L is due to the spherical aberration...the same spherical aberration that Canon EXPLICITLY LEFT IN BY DESIGN, for aesthetic purposes. Ironically, at f/2.8, the Sigma beats the Otus corner to corner...you can see a bit of falloff on the Otus at f/2.8 and f/4, where as the Sigma is sharp through and through:



Similarly, stop down the lenses a bit, and the vignetting issues clear right up as well. The 50L actually has better vignetting than the new Art 50 at f/2.8:



I would share the CA fields maps, however again, DXO, in all their biased wisdom, only seems to have produced CA data for the maximum aperture. CA DEFINITELY drops in the corners as you stop down, since the narrower aperture is blocking light from the periphery of the lens where the most CA occurs. As such, it is only possible to compare the wide open performance, where, once again, the 50L is at it's worst (although again, much of it's wide open performance is explicitly by design, in order to achieve a specific aesthetically pleasing result.)

5
EOS Bodies / Re: 1d IV vs. 7D II
« on: Today at 09:25:37 PM »
Do let me know when this thread gets back to a discussion between 1D IV vs 7D II.
Alas, it seems to have run off into another FF vs APS-C discussion...

Everything I've said about FF vs. APS-C applies to APS-H vs. APS-C. It's sensor area that matters, so from a sensor IQ standpoint, the 1D IV wins. The 1D line also gets extra attention to all the fine little details, the small things that require a lot of extra hands on time to tweak and tune and refine. It's a large part of the reason the 1D models cost more...they are highly and optimally tuned. You can ask almost any 1D owner regardless of generation, and most will tell you they love the out of camera quality in every respect...higher sharpness, lower noise, better color fidelity, etc. etc. The same fine tuning applies to all the other non-sensor aspects of the camera as well. The 1D IV had a much better AF system that performed much better than the 1D III and any other Canon camera of the time. It had the high frame rate, the higher performance shutter, etc.

I think it would be very difficult for the 7D II to beat the 1D IV. At best, Canon might achieve parity, and some non-sensor features might be better (i.e. better AF system), but I generally don't think IQ will be better.

6
EOS Bodies / Re: 1d IV vs. 7D II
« on: Today at 09:21:47 PM »
Pretty much an excellent description of what to expect.  Most of us agree that the 7DII will not equal the 1Dx.  The 1DX is really purpose built for sports and action photography.  The 7DII will be purpose built for video.  The writing is on the wall.  While I'm sure it will offer much more than the 7D and offer better IQ, much of the design is going to be built around a videographer's dream.

Heh. I think it's all the mystery that surrounds the 7D II, and what it might actually end up being in the end, is what has everyone so intrigued by all the 7D II rumors around here. It so long overdue for release now, people are biting off their fingers waiting for some concrete news to finally hit the rumormongers.

My fear is that a feature rich camera tailored to videography is going to be priced out of the range of most photographers who dont need the video features.  I predict this camera will come to market around 2800.00 which will mean more like 3200.00 because we know Canon will milk us for every penny in our accounts.

I honestly think the chances of that happening are roughly around 0.0000292372349%.  8) Canon would kill off the 7D II before it ever has a chance to start if they priced it at $3200. The original 7D was $1700 (or $1900 with kit lens.) It's been on the market for a very long time, has an established and strong following, much of that following is eagerly awaiting the release of the 7D II, and it's an APS-C camera. Pricing it at $2800 means they are pricing it $1100 higher than the original 7D. The original 5D II body only was $2700, which means the increase in price to the 5D III was $800 at release (and today stands at $700 MSRP, and $0-$100 when you factor the average in-cart price, which has been between $2600 and $2800 frequently lately for gray market, and around $2800 for official market). I'd say that $800 is the absolute maximum of an increase we can expect to see, hence the maximum potential price of $2500 I mentioned before.

To make things worse just because they like to make us feel more pain, the initial order will likely be kits with lenses they have a boat load of stock on.  So we are talking an initial out-lie of about 3600 to 3800.

Again, I think that is highly unlikely. That would utterly kill off the 7D line...for the demographic I think is most highly interested in the 7D II, those prices are well out of the range of "generally affordable." People may want to buy them, but so many simply wouldn't be able to afford them. That would be really bad for Canon's bottom line. Greed works in both ways...the "greedy" want to make as much money as they can, which means they have to find the price point that will sell the most copies as often as possible...and it really isn't the "greedy" company that sets the price, the market, the consumers, set the price by buying when prices are good, and not buying when prices suck. I don't think that the 7D II will hit the street with a price higher than $2500, and if it does hit the streets at that price, it will most likely be primarily due to the economic disaster brewing in Japan with higher taxes and more quantitative easing, and it will still hurt Canon. I think a price closer to $2000, give or take a couple hundred, is far more likely, as it would satisfy Canon's bottom line goals due to higher (probably significantly higher than at a $3800 price point) sales volume.

7
EOS Bodies / Re: 1d IV vs. 7D II
« on: Today at 08:57:43 PM »

There is no chance the 7D II is ever, ever, ever, ever, EVER going to "trounce" anything with a larger sensor. Just not gonna happen.
If we assume a similar number of pixels and similar level of technology, you are right. However, take a 50 megapixel FF camera and a 20 megapixel APS-C camera and you can expect similar levels of performance.... but go the other way and make a 12 megapixel FF camera and now you have a camera that shoots ISO 409600 like an APS-C camera shoots ISO 12800.... And likewise, compare a 7D2 to a 1D and see what happens..

First off...has anyone actually seen the sample still images from the A7s? Despite it having only 12mp, it's high ISO images are pretty crappy. Even the 6D does better at high ISO RAW than the A7s for some reason. Most of the "wow" stuff I've seen about the A7s has been video related, and I think Sony's BIONZ X processor is really what's doing all the amazing stuff. The A7s is still an Exmor...and unless Canon has tweaked the design, I believe Exmor sensors still digitally boost after CP-ADC for all ISOs. That might explain the lackluster high ISO RAW performance...

Anyway...your talking about pixel performance. On a per pixel standpoint, yes, the individual pixels of a 12mp or 10mp or 8mp 7D II would perform better than the individual pixels of a larger sensor with smaller pixels. But again, that doesn't matter. Pixel size doesn't really have anything to do with it. A single pixel doesn't make a picture. Multiple pixels in concert make a picture. Lets say we have a 50mp 1D XXX (;D) and a 12mp 7D II. Will the 7D II perform better than the 1D XXX? Hell no. There is no inverse trouncing going on here.   ::) The 7D line will forever be in the position of leghumping Ms. 1D while she's in the middle of pole dancing for photography nerds.  :o Why? Because so long as you are not constrained by reach...a larger sensor will always gather more light. It's sensor area that matters, not pixel area. The 50mp image can always be downsampled to the same dimensions as the 12mp 7D II. More pixels interpolated into less area...that only and always means one thing: Better results.

I used to think the same thing, years ago...that bigger pixels would make smaller sensors perform better, but the theory doesn't fit with the idea that only pixel size matters for camera performance. Pixel size is, for all intents and purposes, a non-factor. Sensor area is what matters. 36mmx24mm = 864mm^2, whereas 22.3mmx14.9mm = 332.27mm^2. That is a ratio of 2.6:1 in favor of the FF sensor. Pixel size doesn't even factor into the equation.

Now, what does factor into the equation is quantum efficiency. It we compare the original EOS 1Ds body from way back when, the 7D of today will perform better in some ways. The quality of silicon back in those days was not as high as it is today, and quantum efficiency wasn't anywhere close to where it is today (I think somewhere in the 20% range...the 7D has twice that, so like my explanation earlier about going from 41% to 82%, going from 20% to 41% is significant.) The lower quantum efficiency and older, inferior sensor design are going to cost the 1Ds in comparison with the 7D. However, the 1Ds was upgraded...we got the 1Ds II, 1Ds III and now we have the 1D X. That's why I try to refer to the "1D line" and "7D line". Any technological improvemnt you can think up for APS-C sensors can be applied to FF sensors. There is no technological improvement for APS-C sensors that can ever give it an edge over FF sensors because they all get the same technological improvements in the end. (That's basically what you said in the second half of your post.)

So...it boils down to quantum efficiency. The 7D is already at 41%. The 1D X has 2.6x the sensor area of the 7D, however you can only get up to 100% Q.E. before you run into the laws of physics where absolutely no more improvement can be made.

On an equivalence basis...bigger sensor, more light, better sensitivity. Pixel size need not apply, the job of sensitivity is already taken. ISO 400k on a 1D XXX is always going to trounce ISO 400k on a 7D II. Just as much as ISO 400k on a 55x44mm MF sensor is always going to trounce ISO 400k on a 1D XXX.

8
At the risk of being flamed, I feel that the many photographers around here that proclaim IS to be of no use on lenses wider than 85mm are being snobs. It's as if they are saying, "My technique is such that I would derive no benefit from it and if you feel the need for it, well you just suck."  OK, that's a bit of an exaggeration, but you get my point.

I used to think the same way as you- the pros who suggest IS isn't important at wider FLs are snobs.
But let's dig deeper- there is SOME truth to it, as I have realized with time. Not all true, mind, because I still think IS is important.
However, I think IS gives a false sense of confidence to inexperienced photographers. They feel they can shoot a photo at 1/17 just because they are shooting with a 35mm lens with IS. But they don't understand the limitation of shutter speed vs subject movement.
Pros point at the fact that you realistically cannot shoot lower than 1/n (put your favorite number here) unless you want motion blur or you are shooting still life.
Now, for longer focal lengths, n is a larger number:
Consequently 1/n is higher, and 1/n divided by factor of image stabilization still remains high. So motion blur is avoided.

Now, less knowledgeable people have taken this maxim, misunderstood it, and propagated it at face value- that IS is unimportant. I think it is just a misrepresentation and generalization of otherwise sound logic.

Image Stabilization has one purpose, and one purpose only: To reduce blur from camera shake at slower shutter speeds. There is no other purpose for IS, thats its sole reason for being.

The notion that IS is unnecessary for focal lengths below 85mm was true. As pixel sizes continue to shrink, that notion will become increasingly less accurate and less valid. Smaller pixels register smaller degrees of camera shake. In other words, smaller pixels magnify the effect of camera shake to a greater degree. Were around 4µm pixels (+/- 0.3µm) now, but they will continue to shrink. Having IS on a 50mm lens will be far more valid at 3µm than it is today at 4.3µm. Having IS on a 35mm lens will be more valid at 2µm than it is today.

I don't know how small pixels will shrink...I think were going to have problems with other things before APS-C and FF cameras get sensors with pixels in the 2µm range (exponentially increasing in-camera processing power requirements, similarly increasing computing power needs just to import and process RAW images, significant increases in storage space needs, etc.) By the time we actually do get down to pixels a quarter the area of pixels today, I think the argument about having IS on lenses shorter than 85mm will largely resolve itself...the results will simply speak for themselves.

9
EOS Bodies / Re: 1d IV vs. 7D II
« on: Today at 05:49:22 PM »
Jon, do you see a market for the 7DII except for those high-end shooters looking for reach?
If they want quality they have the 3 FF cameras.
If they are looking for value they have the 70D.

First, there is more to IQ than what the sensor does. I've said this a lot before on these forums, as had Neuro. Sometimes the focus capabilities and frame rate of a camera are VASTLY more important than how good the sensor is. In that respect, there aren't three FF options...there is really only one: The 1D X. The 5D III has a decent frame rate, but if the 7D II hits the streets at 10fps, the additional 4fps over the 5D III is going to be very significant. Were talking about a 67% increase relative to the 5D III. The 6D, while it has it's advocates, and it definitely pounds out the High ISO IQ, is definitely lagging in the AF area. That is not to say the 6D AF is bad...however it's no 61pt AF system either.

If the 7D II hits the street with 10fps, a comparable APS-C optimized AF system to the 61pt system (say 41pts?), and a 20-24mp sensor, then I absolutely think it will have a market, and I think it will sell like hotcakes. You definitely cannot compare that to the 6D. The only benefit the 6D has going for it is the larger sensor...but that is one out of many factors that affect IQ. The 5D III, in circumstances where frame rate is not critically important, will probably still give the 7D II very solid competition, but in the cases where frame rate is critically important, the only real full-frame counterpart to a 7D II with such specs would be the 1D X.

So yes...it will definitely have a market. I suspect they will fly off the shelves, despite the existence of the 6D. I suspect many a 5D III owner will buy one as a backup. I know for sure that a lot of aspiring amateur bird photographers will be picking one up, especially if a new 100-400 hits the streets along with the 7D II.

The reasons the 7D was a success have not changed. Nothing has really changed. The only thing that would kill the 7D II is if it hit with a MSRP over $2500...then I think that would kill off early adopters and slow sales until the price drops below $2500 at least (I think a price around $2000 is most likely.)

If Canon wants to replace the 1D (and IMO that's the only reason for 7DII to exist), Canon will try to replicate the IQ as close as possible. And that will mean lower MPs.
Note that Canon was pretty conservative with increasing megapixels on their 1D line.
They must have noticed people who want reach are wiling to sacrifice resolution for light sensitivity.
Mind you, the difference between APS-H and C isn't as much as with FF, so innovation in sensor light-sensitivity might well allow the newer APS-Cs (maybe not 7D though, if it still has the 70D sensor) to trounce the 1D line.

Why would you think the 7D II is a replacement for the 1D? The two lines are designed for completely different groups of buyers. The 7D II is not, has never been, and will never be a replacement to the 1D X. Your completely ignoring the price difference here. The price of the 7D II is likely to be less than 1/3rd that of the 1D X. It doesn't really matter how good the 1D X is, or how good it's potential successor is...price is the real segregator here. The 7D II will sell because it will fall within the realm of generally or eminently affordable to the majority of middle class buyers. At $6800, the 1D X does not fall into that class, not even close.

Regarding the megapixels of the 1D X, Canon didn't get away with anything, nor were they conservative with anything. It's so funny how short peoples memories are. :P I remember, very very clearly, the loudest and most vocal outcry from Canon customers before the releases of the 1D X, D800, 5D III, and D4. The loudest demand, by a very LARGE margin, was: "Fewer megapixels! Better high ISO!" That was what people wanted, was VERY MUCH what people wanted from the 1D IV/1Ds III successors. Canon didn't skimp, get away with, nor was conservative with the 1D X. They delivered EXACTLY what their customers literally demanded. For those who can afford it, it seems to be a raging success as well. It's converted more than a few pro Nikon shooters to the Canon camp, and has made raving fans of existing Canon 1D/1Ds users.

There is no chance the 7D II is ever, ever, ever, ever, EVER going to "trounce" anything with a larger sensor. Just not gonna happen. Again, outside of the one caveat I mentioned, the IQ you get from a sensor really has nothing to do with the pixels. Improvements in pixel technology are primarily going to reduce read noise, which is already a very small factor in the deep shadows, and secondarily improve sensitivity. The quantum efficiency, Q.E., of the 7D is already at 41%. To double the noise performance, Canon would have to achieve 82% Q.E. I know of sensors that can achieve 82% Q.E. at around 650-600nm, but all of them require significant cooling to do so...usually a Delta-T of -50°C or more. That kind of cooling requires a lot of power (for example, most high Q.E. Astro CCD cameras use two- or three-stage peltier cooling...a peltier, or TEC is a thermoelectric cooling device that uses a P-N transistor matrix to create an electronic heat pump...they draw significant amounts of energy.)

Now, assuming Canon did somehow manage to improve the Q.E. of their sensors to 82% at average operating temperatures (pretty much not possible, dark current is going to be very high at operating temperatures of 60°F and above) but just for the sake of discussion, let's assume they do. At 82%, they can double their noise performance (reduce noise by half). That still doesn't cut it. The 1D X has a total sensor area that is 2.6x greater than the 7D (and any potential 7D II), so you would at least need to increase the 7D II's Q.E. by 2.6x instead of just 2x. Well, that isn't actually possible. To double Q.E. again beyond 82%, you would need 164%...but you can't have better than 100% Q.E. (quantum efficiency is the ratio of conversion of photons to released electron charge in a photodiode...you cannot convert more than 100% of the incoming photons.) You can't even get that .6x better than 82%, because that would require another 50% Q.E....or 131%.

All that matters in this particular area is total sensor area. So long as Canon does not make the 7D line use at least a FF sensor, it will never be able to "trounce" the 1D X in terms of equivalent IQ. In terms of reach, all that matters is how big the subject is reproduced on the sensor...in which case smaller pixels mean more detail, but total light gathered for your subject is roughly the same regardless of sensor.

10
*Sigh*

 Comparatively, it has the same resolution, better transmission, less distortion, and less CA than the Otus.


Sigma is 1.7 T stop vs Otus at 1.5 T stop.

Ah, you are right.

Regardless, the Sigma looks like an excellent lens, and at only a quarter the cost of the Otus.

11
*Sigh*

DXOs Lens test results are so useless. They rate it less than the Otus, as they should, however all of the measures they choose to exhibit would otherwise indicate that the new Sigma 50 should be the better lens. Comparatively, it has the same resolution, better transmission, less distortion, and less CA than the Otus. Only in a footnote do you actually learn why DXO rates the Otus higher: It has sharper corners.

Bleh. DXO. Bleh. It's like they just barf up test results and let the chunks & giblets remain where they plop.

I think the world would be well-served if DXO just gave up on lens tests alltogether, nuked their lens tests database, and just stuck with sensor tests. (And furthermore, I think the world would be better served if DXO did away with scalar test "scores"...just as useless as the chunks and giblets that is their lens tests.)

12
EOS Bodies / Re: 1d IV vs. 7D II
« on: Today at 04:24:11 PM »
Thanks, Jon Rista for trying to put this back on track.

Apparently some don't get why this matters. If physics really does limit how well an APS-C sensor can perform at higher ISOs (and I have no reason to doubt you on that), then the direction Canon decides to go with the 7DII sensor will tell us much about what the company thinks about the future of high-end crop sensor DSLRs.

If Canon were to release a 16mp 7DII, they are saying something quite different than if they release a 22-24 mp 7DII.

The relevant question for Canon is most likely to be – which one will generate more demand in the marketplace?

Many would say the 16mp sensor, which should have better high ISO performance than the current 18mp sensor. In effect, Canon would be following the same path with its flagship APS-C body that both they and Nikon have followed with their flagship full-frame bodies.

But, what really would be the demand for such a body – a good, maybe even great all-purpose crop body, but still not as good as the almost identically priced 6D in terms of high ISO performance. The 6D would be a better all-purpose body; and would there be sufficient differentiation between the two in the marketplace?

Or Canon could go the other way and release a 24mp crop sensor body -- essentially conceding the high ISO niche to full frame. Would this camera find a bigger market?

While the relative advantages of a crop sensor for reach have been much debated, almost everyone concedes that in cases where the shooter is distance limited and significant cropping is required, pixel density does matter. You will always reach some point where there simply aren't enough pixels to give you a usable image.

So, why the reference to the 1D IV? Because that was the point at which Canon abandoned the sensor that many argue passionately was the ideal compromise between size and reach.  We can't assess or intelligently speculate without first knowing what the constraints are.

If the ISO performance of the APS-H sensor can never be achieved with the smaller APS-C sensor, then Canon must decide which path to go down.

So, unlike the many, many threads where individuals focus solely on what they want and assign human motives to a large corporation (Canon doesn't care...Canon doesn't listen...Canon had better do this...) this is simply an effort to explore what the reasonable expectations may be, so that it gives us a better idea of what choices Canon is facing and, when they announce their decision, we have a better idea of where the market is going.

Thanks for the detailed thoughts. I understand where your coming from now, so maybe I can provide a clearer answer.

For all intents and purposes, all else being equal, the only thing that actually matters when discussing IQ is the size of the sensor. The size of the pixels does not actually matter. You could have an FF, APS-H and APS-C with the same size pixels, to eliminate pixel size as the ultimate determining factor here. Assuming equivalence (same framing, same depth of field), per-pixel noise will be the same, however the FF will always be better than the APS-H which in turn will always be better than the APS-C. ALWAYS. Note the factors here: Same framing, same depth of field.

So, why? Why is it that the IQ edge will always be FF > APS-H > APS-C > 4/3 > Small Form Factor? If we dive into what is necessary to achieve identical framing AND identical DOF, you'll understand why.

Identical Framing

To achieve identical framing, you either use a longer lens, or get closer. It's pretty much as simple as that. However in achieving identical framing, you are changing the total amount of light, for your subject, that falls on the sensor. It really doesn't matter if the sensors have the same pixel pitch, or the same total pixel count, either way, the larger sensor is going to be gathering more light in total when you normalize framing.

Identical DoF

Now comes the part that everyone usually assumes is the caveat that somehow lets a smaller sensor achieve better results than a larger sensor. To achieve the same depth of field with a larger sensor, you need to stop down the aperture. By stopping down the aperture, your negating the benefit of gathering more total light. The caveat stops there, however. At worst, you'll simply normalize the results...the FF sensor will have the same amount of noise as a smaller sensor. The Identical DOF factor is not a magic bullet that can ever allow a smaller sensor to perform better than a larger sensor.



Let's take two sensors that have the same number of pixels. The 1D X and 7D are pretty ideal examples, since they both have exactly the same pixel count. Take the same shot with both cameras, and in not a single case will the 7D image ever be better than the 1D X image. The larger pixels trounce the 7D, at all ISO settings.

Assuming your aiming for the same depth of field, then the 1D X image will at worst look the same as the 7D images, however there are actually technological improvements that make 1D X images always look better than the 7D, even when using significantly narrower apertures.

Everyone always talks about the "equivalent" cases, however in my experience, in practical scenarios equivalence is rarely ever actually desired. One of the big reasons for buying a camera with a larger sensor is to get a THINNER DOF. The moment you open the aperture up on a larger sensor, all hope for the smaller sensor is gone. Not only are you gathering more total light simply by virtue of greater sensor area, but now your allowing more light through the lens. As is also always the case these days, the pixels of FF sensors are larger than the pixels of APS-C sensors...so you have more total light with larger pixels along with the use of a wide aperture (at least as wide as the one you were using with the APS-C).

There is also often another benefit with larger sensors. They usually have more pixels than smaller sensors. For example, if you fill the frame with your subject with both a 5D III and a 7D, the 5D III is not only putting larger pixels on the subject, it is not only gathering more total light...it is ALSO putting more pixels on the subject. If you then downsample your 5D III images to the same dimensions as native 7D images, the extra pixels of the 5D III provide more source data, such that when interpolated, the 7D-normal outcome is even better, sharper, less noisy, more accurate.

This is not always going to be true anymore...especially if Canon moves to a 24mp 7D II. However that does not negate all of the other advantages of using a larger sensor. The more total light is always going to be the case...larger sensor, more total light...more total light, higher SNR, less noise.



Finally, there is the one caveat that actually does give smaller sensors the edge. Or rather, to be more accurate, the caveat that gives smaller pixels the edge. Reach. The much-vaunted reach factor. The only case where a smaller sensor can give you a performance edge is when you are literally reach limited. You cannot use a longer lens, and you cannot physically move closer. You are either blocked by some active barrier, at the shore of a body of water, or moving closer would scare away your subject.

In this case, and pretty much only in this case, we are actually NOT talking about an equivalent set of circumstances. Equivalence requires identical framing...however the larger the sensor, the less total area of the frame your subject is going to take. We now have identical subject size. Assuming that your FF sensor has larger pixels than the APS-H, and that in turn has larger pixels than the APS-C, then the APS-C is actually going to perform better. Some would argue that the larger sensor is still performing better...after all, it still has larger pixels. If one is willing to completely ignore the level of detail being resolved, then indeed, the larger pixels will still be less noisy. But were talking about reach here...the level of detail being resolved is exactly what matters. In this case, as the facts of physics would have it, your actual subject is getting the same amount of light in both systems. It's a matter of area, and the absolute area of the sensor is the same, even though relative area (to the frame) is different. The key difference is the amount of detail...larger pixels resolve less detail, and blur the edges of your subject with nearby background (and/or foreground) detail.

In reach-limited scenarios, with identical subject size at the sensor, smaller pixels perform better.



There is a lot of value in smaller sensors with smaller pixels. For the less skilled, it means you can get some detail and ultimately end up with a good composition without having to have other skills to get close, or compose right in camera, etc. With more pixels, you can always crop to enlarge and compose better.

If you have skill, and tend to photograph things that need reach...wildlife, birds, airplanes, even sports, reach is a very valuable tool.

Even more so, it is a valuable tool to those with limited budgets. To achieve equivalence with a larger sensor, you need bigger lenses. To justify the cost of full frame, especially a high end full frame, you need to be able to produce better images, so you need bigger and better lenses. A crop sensor with lots of pixels means you can get an order of magnitude more bang for your buck, and often in a smaller, more portable and manageable package. More pixels doesn't really hurt you, either, as in a reach-limited scenario, your subject is still covering the same absolute area of the sensor...more pixels simply means more detail...and you can always downsample.

13
EOS Bodies / Re: 1d IV vs. 7D II
« on: Today at 11:21:13 AM »
On the basis of better IQ and lesser noise at high ISO, there's a good chance the 7D II will be at least as good as the 1D IV. In there last few years, there have been great strides made in sensor technology. Let's hope the camera that finally comes to market doesn't have too many, hence smaller, pixels to negate that virtue.
On the other hand, the reliability and durability of the 7d II will likely not come close to the 1D IV (nor any others in the 1D family) unless it's sold at a price point above the 5D III. Since it's being billed as a prosumer camera, we can  be pretty certain THAT's not going to happen.

There have been strides in sensor technology, however pixel size still dominates the determination of how much noise you have. Smaller pixels will always have more noise, that's a simple matter of physics. We have improved READ noise with better sensor technology, but read noise is only a small contribution to total noise (especially at high ISO)...photon shot noise is the primary source of noise in images. The larger pixels of the 1D IV will always win out against smaller pixels of APS-C sensors. The only way the 7D II could do better is if it had larger pixels than the 1D IV, however that would make it something like a 10mp sensor...highly unlikely.

14
Lenses / Re: Teleconverter advice
« on: Today at 09:29:22 AM »
I do not own one myself, however there are plenty of comments around the web about the MC4. There are a plethora of comments about strong vignetting on the MC4, especially on FF but even when used on APS-C. IQ is better in the center, but commentary also seems to indicate that IQ is still not generally as good as the Canon 1.4x TC III (despite what the german article indicates).

I got a 300 DGX Blue Dot, however if the MC4 had been available for purchase at the time I purchased, I'd probably have one of those, despite the vignetting. At the time I bought, it simply was not in stock at any of the major distributors (Amazon, Adorama, B&H...I generally don't like buying from anywhere else, had too many problems.) I waited for a while, and eventually got the 300 DGX.

From what I've read, I am honestly not sure that the core IQ issues that I experience with the DGX are fixed with the MC4. My primary issue with the Kenko I own is not really with vignetting or corner sharpness...it's with the way it convolves detail, and especially the way it renders out of focus blur. The MC4 might be a little better than the 300 DGX in the center for the focused target, but the "scratchy" background blur, the warped and spotty highlight blur circles, and "rough" detail (it can be sharp...but there is something else going on with it that makes images produced with the 300 DGX just not as appealing as those produced with the 1.4x TC III), as far as I can tell based on commentary and sample images those issues exist with the MC4 as well (and probably most/all other Kenko TCs).

If you don't really care about your background blur, the MC4 should be sharp enough, but it still doesn't seem to give the same kind of aesthetics to it's IQ as the Canon 1.4x TC III does.

15
EOS Bodies / Re: 1d IV vs. 7D II
« on: Today at 09:06:52 AM »
Okay, I know one is discontinued and the other is non-existent, but this is mostly for fun and a bit of learning.

Do the experts here think that the overall image quality of the 7DII will match or at least come close to the APS-H 1D IV? Why or why not?

It would really depend on what aspect of IQ is most important to you. Do you need to resolve the finest possible detail, or is low noise the most important thing?

I don't think IQ is some rigidly definable thing. There are objective traits of IQ, and there are subjective traits of IQ. If you require the ability to resolve fine detail, especially at a distance, the 7D II will probably fare better. If you expect the lowest possible noise and need to use higher ISO settings, then the 1D IV will be the better option.

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