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Messages - dtaylor

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301
EOS Bodies / Re: 7DII and D400 Specs
« on: February 27, 2013, 10:23:02 PM »
As I have said before, they may be able to achieve supreme sharpness with $13,000 super telephoto lenses

Oh please. jrista's point about Canon updating their lenses is well taken. But there are plenty of lenses which can produce tack sharp results on crop without a $13k price tag. Canon is updating cheaper lenses as well. As sharp as I thought my 70-200 f/4L was, the 70-200 f/4L IS takes it up a notch, just like jrista's experience with mark II L super telephotos. And it's not $13k.

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But when it comes time to shoot a wide angle image with a 24 MP or higher crop sensor, good luck ever getting sharpness on the level that you could from the same pixel count via a full frame sensor and lens, taking in the same angle of view Never going to happen...not ever.

Except that it already happens with Sony/Nikon 24 MP sensors, top notch glass, and a little USM.

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We'll never see a wide angle zoom rectilinear lens, that goes to 10mm for a crop sensor camera, that will be sharp to the corners wide open, with no CA, and zero "decentering"...and somehow rival the best 14 or 15 mm wide angle full frame zoom.  Not going to happen.

I'll gladly pit a Tokina 11-16 f/2.8 (good sample) against a Canon 16-35 f/2.8 (good sample).

You keep using that word 'never'. I don't think it means what you think it means  ;D

For people who think crop will 'never' do this or 'never' do that, you better spend some time looking at the world of biology. Because eyeballs, both human and animal, routinely do things that you say much larger crop sensors should 'never' be able to do. If our eyes do it, then it's physically possible, and you're a fool to bet against the march of technology and Moore's Law when it comes to the physically possible.

When DSLRs first hit the scene I heard repeatedly that a DSLR would 'never' out resolve 35mm film (happened at 12-15 MP); 'never' produce large prints that could rival MF film (happened with the 5D2, and then the 16/18 MP generation of crop sensors); and 'never' have DR like neg film (today's FF has more DR then all but a couple emulsions). When the 5D was popular I heard that crop would 'never' out resolve it or have better noise (again, happened with the 16/18 crop generation).

Unless a manufacturing break through renders crop obsolete by making FF just as cheap to build (doubtful, but never say never), we will see crop bodies in the future that out perform today's D800. And we will see even smaller sensors in P&S super zooms that rival today's DSLRs. Not if. When. I guarantee you that designers will exploit every advantage they can get as time goes on, including lenses that change shape, liquid lenses that can alter their characteristics like an LCD can alter its display, super dense sensors, custom in camera processors that put today's best graphics cards to shame, etc, etc. We may even see biologically grown sensors, at which point MF might be as cheap as today's Rebels, shattering another 'never'.

So tell me again what's 'never' going to happen. It amuses me.

302
Excellent post. Thank you for digging up and laying out the formulas. I remember where they're at, but I was being too lazy to dig out the book and copy them. You posted them along with a clear explanation.

I would only add that post processing can recover details <MTF50, giving more potential to the 24 MP sensor past it's diffraction "limit". And that diffraction is not the same for all wavelengths, something sensor designers are aware of and will likely exploit in future very high resolution sensors with very high speed in camera processing. At that point you adjust the Bayer pattern to gain detail and process it all down to a file size smaller then the native sensor output, but with more detail then an image from a regular Bayer sensor.

Thanks again for the post!

303
EOS Bodies / Re: 7DII and D400 Specs
« on: February 27, 2013, 06:33:30 PM »
I'm not saying its worse, its just the extra MP don't make any difference to the resolving power once diffraction has set in.

I've pointed out twice now that it actually does. This is not opinion, it's science that was worked out a long time ago. Optical resolution does not work the way the majority of people assume it works, with the weakest link "capping" or "limiting" the entire system to its resolution. The resolution of the total system is always lower than the weakest link. And increasing any component in the chain...not just the weakest...will increase total resolution. Whether the increase is practical and observable is another question entirely, but to wrap your mind around some questions in photography you have to understand how resolution actually works.

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Take another example - scan a photo which was a bit blurry -

False analogy. Here you are changing the target resolution rather than the resolution of a component in the optical system.

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However, back to the meaning of my original point, do we really need all these MP? Do you need 24MP from your crop camera?

I don't "need" it. But it's not going to hurt anything, and it's a step towards higher resolutions that will show noticeable improvements in the large prints I make. Under the best conditions, it might just improve my prints today.
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going from 3 to 6MP is a very real difference. Going from 18 to 36 MP isn't.

Go ahead and compare 36" landscape prints from the 7D (or 5D2/3) and the D800 and say that.

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We're at the point of diminishing returns now - especially as lenses and physics are now becoming limiting factors, and virtually no-one needs to print anything that big and that detailed. If you really do, a larger format than APS-C will yield more real life improvements at such high MP counts. Marketing is leading this drive into the unneeded.

As jrista points out, Canon is revamping their entire lens line because they know where this is heading. Moore's Law isn't going to stop because a few people claim they don't "need" higher resolutions. Granted there are ultimate physical limits, but the end of this road is probably 200 MP FF sensors and the equivalent APS-C sensors. The camera may pre process these images to smaller pixel dimensions for better file sizes, but it will use every pixel in doing so, and the resulting output will be stellar, a match for today's MFDBs.

Back when I bought my first DSLR, a 10D, you could have said a larger format would serve me better then incremental DSLR improvements. Except that those incremental improvements added up to a 7D that produces 24" prints to rival anything I've ever made or seen with 645 film. I say keep the improvements coming.

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10-22 and 17-55. Admittedly, the 10-22 does have the 17-40 beaten when it comes to detail at larger apertures in the corners, so to call the cheaper L lens comparable is debatable.

The Tokina 11-16 f/2.8 really has the 17-40L beat, and is cheaper.

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But the 17-55/24-105 comparison is a good one. The 24-105 when used on FF goes wider, longer, offers more detail, is brighter (f2.8 on crop = f4.5 on FF), and (at least in the UK) cheaper. OK, its vaguely bigger and heavier, but you can't have everything...

f/2.8 != f/4.5 on FF. I cannot shoot a crop body at f/2.8 and a FF body at f/4.5 and hold the same shutter and ISO. I realize what you're getting at (i.e. FF noise or shallow DoF), but it's still not the same. And I would argue the detail claim as well.

That said, they're basically the same price at B&H.

304
EOS Bodies / Re: 7DII and D400 Specs
« on: February 27, 2013, 02:26:31 AM »
jrista - point well proven with some great shots!

305
EOS Bodies / Re: 7DII and D400 Specs
« on: February 27, 2013, 12:06:49 AM »
If you have an aperture so small that both a high MP body and a low MP body have diffraction, the high MP body will have no advantage. It doesn't matter how finely the sensor can resolve the blur projected by the lens, its still just blur.

Once again, resolution does not work like this. First, diffraction is not a hard limit. Second, even at extreme apertures where diffraction approximates a hard limit, a higher resolution sensor will still yield superior results. Why? Because the resolution of a system is not the weakest link in the chain. It is computed from a formula using all the links and is always less than the weakest one. Increasing any link results in a higher final resolution, but the final resolution is always less than the weakest component.

Practically speaking the increase may not matter outside of a lab. And for 18 vs. 24 MP I'm guessing it won't matter much outside of a lab test even at f/2.8. But putting a higher resolution component in the chain will never result in worse performance.

I hate the term DLA because it's inaccurate and it conveys the idea of a "hard limit" that goes down as the sensor resolution goes up. It is not at all consistent with the science of optics. And it plays off another issue in general conversation: the portrayal of resolution as a single number. It's not a single number. It's an MTF curve. Your comment "it's sill just blur" illustrates the problem. The 7D is "diffraction limited" at f/6.9. The way you describe this, f/8 produces "blur." The reality is that detail with X contrast at f/6.9 has some value <X contrast at f/8, and can be restored to X contrast with sharpening. I can make f/6.9, f/8, and f/11 24" prints all day long and you won't be able to tell me which is which.

At some point detail is truly lost, i.e. contrast of 0%. But the point is not immediately past the DLA.

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While a 24MP sensor with DLA setting in at f6.0 will allow for some lenses to shine at larger apertures, where will this marketing machine stop? If the next round of crop cameras hit 40mp, and then after that 60, will you still be arguing for it to carry on?

I've seen convincing arguments for 100-200 MP FF sensors, assuming technology allows you to hold the line on noise/DR. Why? Because of another point that's not reflected in simple DLA numbers tossed around on the web: the impact of diffraction is different for different wavelengths of light. And if your sensor design + RAW software takes this into consideration, it can maximize the detail recovered. We will eventually see that point in digital camera design.

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There comes a point where making EF-S glass good enough to resolve such detail at the large apertures needed to avoid diffraction becomes unaffordable. We're already at the point where the 17-40L and 24-105L cost less than their EF-S counterparts.

Which counterparts are you thinking of?

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But for those than want the extra MP so they can resolve more detail, in all but very select circumstances and with all but the very best glass, they'll be very dissapointed.

I'll agree that 18 vs. 24 MP is not a very big deal and is driven by marketing. But sensor resolution is not limited by diffraction in the way you think it is. And we will see even higher resolutions in the future. If a jump could be made today to 35 or 40 MP while holding the line on noise/DR, it would produce observably better prints.

306
EOS Bodies / Re: 7DII and D400 Specs
« on: February 26, 2013, 03:49:27 AM »
APS-H is a nice middle ground; better IQ than 1.6, better reach than FF.

We're at the point of diminishing returns where it really doesn't matter with FF vs. 1.6x. There's hardly a reach gain today with 1.6x. It's there, but you pretty much have to crop even further and then print 24" or larger. With 1.3x in the newest generation of sensors you would never see the gain vs. FF.

Likewise, there's hardly an IQ gain with FF except at high ISO. So the IQ difference between 1.3x and 1.6x, with the sensor tech the 7D2 will have, would be a scientific footnote, not a human observable quantity.

We're long past the days of the 5D vs. the 20D where IQ and reach differences were immediately obvious. 1.3x loses compatibility with numerous lenses and increases costs for no real advantage. It's not coming back. APS-C gives you lower cost bodies and, in some cases, lower cost glass. FF gives you more high ISO room. That's about it.

307
EOS Bodies / Re: 7DII and D400 Specs
« on: February 26, 2013, 03:42:06 AM »
Ps - I really hope Canon resist the temptation to take their 1.6x crop sensor up to 24mp. It'll suffer from softness due to diffraction from f6.0 onwards - mount an f5.6 lens on there and you've got little in the way of options. Even the legendary 300/2.8 II with a 2x TC III will underperform, and leave you with just one aperture option if you want to attempt to utilise all of those megapixels.

Resolution doesn't work like this. In a format, a 24 MP sensor will always out perform an 18 MP sensor whatever aperture you choose. Now even under the best conditions it won't amount to much and may not be immediately obvious in large prints. But it will always be better by some amount. Diffraction is not a hard limit and is not a reason to cap APS-C sensor resolution or to limit your use of apertures.

The current 7D is "diffraction limited" at f/6.9. I regularly use f/8 and f/11, and after post processing even f/16 is fine. More to the point, the 7D is never "worse" than the 10D, 20D, 40D, etc., not even at f/22 or f/32.

High ISO is another non-reason to cap resolution. Noise for an image is determined by technology and total surface area, not pixel size. At least not until you get into the extremely small pixels on some P&S bodies.

The only possible reason to hold back on increasing the resolution is DR. Pixel size is a factor for DR. But if technology eclipses this, my guess is Canon will match the competition. Too many people will see 18 vs. 24 MP as a negative, and Canon's not going to give up that marketing point.

Given the choice I would take 18 MP if it had noticeably higher DR. But that choice may not be what anyone thinks it is, i.e. the DR gain may be less then the resolution gain. And I doubt Canon will give us the choice. Their competitors have settled on 24 MP. You can guess what they will do.

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EOS Bodies / Re: Canon EOS 7D Mark II Spec List [CR2]
« on: February 19, 2013, 01:15:02 PM »
Canon cannot put the same AF-system like the 5D Mark III´s in an 7D Mark II for the mentioned price. So don´t expect it.

Canon could put the 1DX's AF system in every body they've got. The AF components are among the cheapest to manufacture. Like everyone else they use AF specs to segment the market, but the 1DX AF is not actually hundreds of dollars more to manufacture then the Rebel's AF.

Whether or not they will put the 5D3's AF in the 7D2 remains to be seen.

309
EOS Bodies - For Stills / Re: Film EOS Body
« on: February 17, 2013, 07:37:45 PM »
Adding another vote for the EOS3. I actually prefer it over the 1-series film bodies due to size/weight. It's an awesome camera, and the used price right now is a steal.

I was never that crazy about eye controlled focus, though it does work with a reduced set of focus points. (It never works well for me with all 45.) But there are a couple other features I wish were on my 7D. Namely the spot metering mode where you can take multiple readings and the camera will compute the exposure, and the additional metering scale to the right of the viewfinder.

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EOS Bodies / Re: $1200 7D vs. $1800 5D II?
« on: February 14, 2013, 08:40:41 PM »
5D2 if you regularly shoot and make large prints at ISO 1600 and above. OR if you have certain Canon lenses which really work best on FF (T/S; the fast wide primes like the 35 f/1.4).

7D for everything else.

No matter how many times people insist...just insist...there's a HUGE difference when they pixel peep at 300%, they cannot pick out 16x24 or 20x30 prints at ISO 100-800.

And $600 would make a big dent for lenses, either buying one you need out right, or getting you that much closer to one that's more expensive.

311
EOS Bodies - For Stills / Re: Upgrade from 40D
« on: February 08, 2013, 01:50:47 AM »
1) Used 1D Mark III (yeah, submirror AF blah blah)

Sports and wildlife: excellent
Landscape: OK
Low light: OK

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2) Used 5D Mark II

Sports and wildlife: OK
Landscape: excellent
Low light: excellent

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3) Used 7D

Sports and wildlife: excellent
Landscape: excellent
Low light: OK

Not sure what to say here except that you're probably looking at the 7D or 5D2, and not the 1D3 regardless of the cool factor of having a 1-series camera.

If sports AF/fps are critical, 7D.

If >3200 ISO and/or >11x14 low light prints are critical, 5D2.

Low-mid ISO landscape prints are the same from either after post processing, and you can easily print 16x24 and 20x30.

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Since we're going to argue this...

DPReview Noise Test Results at ISO 3200:

7D Chroma: 3.3
5D Chroma: 4

7D Luminance Black: 2.7
5D Luminance Black: 3.1

7D Luminance Gray: 3
5D Luminance Gray: 3.4

I don't like the IR comparometer for high ISO because those particular studio tests are not as carefully controlled in regard to lighting. The "Dave Box" test is carefully controlled, and the 7D clearly edges out the 5Dc.

These results apply to any of the 18 MP APS-C bodies.


313
As for its High ISO IQ, Its better than any crop camera canon makes. DXO even confirms this and my own usage agrees also.

Imaging Resource and DPReview confirm the opposite and publish the test photos and all test details for review (reproducibility, something DxO lacks). Should someone believe DxO or their lying eyes?

If we're going to talk experience, my experience, the experience of members at my photo club, and the experience of a friend with a rather successful wedding photography business all concur. Nobody who has ever claimed the opposite has ever been able to provide images to prove it. If you can you'll be the first.

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Points to consider...

* The shutter counts provided by Canon are estimates of average lifespans. A 1DX might lose a shutter at 10,000 images, while your T1i still clicks at 250,000. That wouldn't be the average, but it certainly can happen and will happen to someone. Don't assume your camera is about to die based on shutter count.

* The 5Dc is definitely better at high ISO then the T1i.

* The T2i / 60D / 7D out perform the 5Dc in all respects, including high ISO / noise. This is a tested, measured, and proven fact for those who want to argue that "FF must always be better!" (See the reproducible tests at DPReview and Imaging Resource.) The differences are small, but in the crop sensor's favor.

* A used 5Dc will have a shutter count equal to or worse than your T1i.

* The 5D2 / 6D has clearly superior noise, sharpness, and fine detail at ISO 1600 and above over the 18 MP APS-C bodies. Add to that superior fine detail at any ISO over the 5Dc. How important this is depends on what you do. 8x10's at 1600 and 3200? It's a non-issue. ISO 6400, 12800, and/or 16x20 high ISO prints? You will definitely appreciate the 5D2 or 6D.

My recommendation:

* If you absolutely need the high ISO performance (i.e. >3200 and/or lots of 16x20 prints at ISO 1600 and above), your budget only allows for a used 5D2.

* If you are leaning towards the 5Dc because you also want a new lens, you should be looking at Canon's 18 MP APS-C bodies. (What crop glass do you have btw?)

* Unless you get one really cheap, it's hard to recommend a 5Dc that will have just as much wear and tear as your Rebel, and fewer features. It is better at high ISO then your Rebel. At the right price it could be a good move with your budget and a lens. But every time I check the 5Dc's they are overpriced because people think FF is "magic" when it's not. At any price I've seen them, the 60D is a far better option.

315
This thread seems surreal.  Unless shooting in the studio under carefully conceived lighting, good post production and printing small, how can so many people say the iq difference between a rebel and a mkiii is similar, not to mention indiscernible?

Because we've taken a wide range of shots under a wide range of lighting conditions, and printed them to large sizes. And at ISO 100-800 the differences just aren't there.

Above 800? Absolutely. Though I would say the 18 MP sensor is good through 3200, the FF sensor shows a greater and greater advantage with each stop past 800. I consider the 5D3 probably the best low light DSLR made. (Haven't tried a 6D.) But if you're not shooting at those ISOs, it just doesn't show an IQ advantage over the many other sensors out there. (Canon's 18 MP APS-C; 5D2 sensor; several Nikon / Sony sensors).

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I don't think that once you shoot the mkiii in the real world, you would ever choose to shoot the rebel.

He just told you he observed the opposite. Should he believe you, or his lying eyes?

Again I'll say that, given the trip, he should keep the 5D3 unless he is short a critical lens and trading the 5D3 for a 7D gets him the lens. It sounds like that's probably not the case, though his kit is weak on the telephoto end. At the bare minimum he's going to need a 1.4x for the 70-200. And I lean towards the comment that even that won't be enough, and a 100-400 will be the bare minimum for wildlife in this scenario.

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