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Messages - jrista

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1171
EOS Bodies / Re: Why are DSLRs so Big?
« on: November 12, 2013, 01:31:03 PM »
With film and manual focus plus manual aperture, there was little in the cameras. Manual film transport too meant all you needed was a tiny battery to power the exposure system, at least that is how I used my dads Tlb canon. And it still works.
Move to a T90 and you get multiple motors for film transport, more buttons and less dials. But to do this you have more electronics which go somewhere. Size goes up.
Move to a digital canon and you have to add in all those things peculiar to digital but absent with film. Rear screen, memory card(s), bigger battery, flash, dials to zoom in or change focus points and so on. You then have to have the buttons spaced such that they are usable.
Following a logical set of steps you can see how dslr bodies range from the 1 series to the rebels. My only criticism of the 1series is the weight! But even that can help with balance or unsteady hands. My 350d seemed to produce many more crooked horizons which are absent (mostly) on the 1dx.   

The now decades-old Canon film 1-series SLRs that used the EF mount were roughly the same size as modern 1-series EOS DSLRs. The size of the 1-series has nothing to do with electronics. It is an ergonomics factor...always has been. The large 1-series have always had the integrated grip...its one of its selling points. The large size offers much better hand-holdability in both landscape and portrait orientations.

That is, has always been, and probably will always be one of the primary arguments for using an SLR-style camera...ergonomics. Even if you have smallish hands, mirrorless cameras are exceptionally small. They really don't fit the hands all that well, and while they certainly save on weight, for all but those with tiny hands, they end up having other ergonomically related problems, like cramping your hands into your face in an uncomfortable way.

From a weight standpoint, one of the most significant weight factors in a modern DSLR is the battery. Larger batteries with much greater capacity are usually the most dense aspect of the camera. A large battery can get you a lot more shooting time before having to swap out batteries, and/or supply the necessary power to move the mirror and actuate the shutter and write huge amounts of data to a memory card at extremely high frame rates. It's a trade off you can choose to make, however...1D X with grip and extra large battery, or 5D III with no grip and a relatively small/light battery. Perhaps at some point in the future dense, heavy batteries might be traded out for some kind of light weight fuel cell that can operate for days under the same kind of load conditions.

1172
EOS Bodies / Re: New high resolution camera
« on: November 12, 2013, 01:21:31 PM »
..but the corners are always going to be crap regardless. Buy a Nikon 14-24 and the necessary Canon adapter, and slap that on your ultra high res FF camera to extract the most you can from the sensor, and push that final output resolution as high as possible.

FWIW - I use the 14-24mm Nikon on a D800 on occasion, it's kind of impressive.  but the corners aren't so great for sure, lots of CA and a bit soft.

You should directly compare the 14-24 corners to canon's 16-35 corners. Sadly (and I own this lens), Canon's corner and edge performance is really atrocious. Corner performance on Nikon's 14-24 is worlds better, and even though it isn't as good as the center of the lens, it is still one of the best zoom lens performers in that range.

Really want wide angle high resolution, try the 14mm Samyang prime instead. It's better in the corners at 1/4 the cost.

Totally agree here. The Samyang (Rokinon) 14mm is my next lens purchase for astrophotography, as it has stellar corner performance with very little coma or CA. And it is a hell of a good price, too ($350 on average).

I'd also like to see DxOmark publish more lens tests using the D800e, the regular d800 is well covered, the e is only published with a few lenses.  AA filter on the d800 is weak but still there vs the e model.

Subjectively comparing center resolution from my long gone 5d2 and 70-200L f/2.8 IS 2 with my d800e with 70-200 f/4 VR Nikon does seem to give a small edge to the Nikon combo but the Canon pair was also providing extremely good detail, especially when using DPP to process it. They'd be hard to tell apart on the same shot, printed at 36"


I don't really trust DXO's lens ratings...they overweight the wrong factors and rely too heavily on the camera's sensor to evaluate the results. It's really too bad here isn't some kind of generic means of testing lens resolution without ultimately linking, inextricably, the lens AND sensor tested.

Anyway, one thing that DXO lens results do seem to indicate is that Canon class is currently quite superior to Nikon glass. It takes a sensor with considerably higher spatial resolution to overcome the raw lens resolving power of most modern Canon lens designs. DXO's raw measurements do clearly demonstrate the value of increasing sensor resolution, though...it is basically an empirical validation of the theory I laid out before. Even with a poorer performing lens, a higher sensor resolution is going to outperform. Same thing goes in the inverse...a higher resolving lens can help support a lower sensor resolution. Same difference either way...increasing the resolution of any single component in an optical system will increase the final output resolution.

Interesting, that while Nikon and Canon have chosen different paths, the final results are quite similar. I guess that means the one key area where Canon needs to improve is sensor dynamic range/read noise. They are still using a decade (plus) old fundamental sensor and ADC design...and it is clearly inferior to the competition. Would be nice if they spent some time bringing their sensor fabrication tech up to par with their competitors with the next generation of DSLR releases.

1173
EOS Bodies / Re: Patent: A Pellicle Mirror by Canon
« on: November 12, 2013, 01:12:10 PM »
I actually disagree with that one, after a certain point. With wildlife/birding when you have a big enough lens it's the non-body arm that's got all the weight on it. Granted it still does need some proper sized grip. The body lens area itself though can be as small/thin as it wants.

I don't think the future of the cameras used for this sort of thing will be small though. Even with the new A7 and what not there are noticeable features that still reserved for "big cameras" just because they are seen as premium features.
My guess anyway ...

The camera grip is critical when it comes to hand-held wildlife and bird photography. You need both arms, and both are just as essential to properly stabilize the rig. Could you imagine trying to balance an f/2.8 300mm or f/4 600mm lens with just one arm? If you have a tiny mirrorless camera with practically no grip attached to one of those lenses, you have no real leverage with your other hand...no way to properly balance such a large setup. I often hand-hold my 600mm f/4 lens for wildlife, and speaking from experience...it is already difficult enough trying to handle it with a 7D. It would be practically impossible with, say, an EOS M. I'd rather have a 1D X, which has more area to grip in more vertical space, than something even smaller than what I deal with now.

1174
EOS Bodies / Re: Patent: A Pellicle Mirror by Canon
« on: November 12, 2013, 01:12:52 AM »
as from a technical standpoint I do not see how an EVF will ever even be as good as an OVF, let alone superior to one. Personally, I am hoping the classic slap-happy, noisy DSLR lasts for another 50 years...after which point I'll probably be dead, and will no longer care.  :P ;D
I agree that for the applications you cite an EVF would not be the solution. However I think that we are not likely to see the abandonment of EVFs but rather further improvement.
Perfection is not really necessary to be able to achieve 98% of what a photographer needs to know before pressing the shutter.
I have been photographing a series of jobs over the last week where I dearly would have loved to pre-chimp my shots.
I was in a variety of fast moving situations with varying light brightness and color temp that necessitated rapid shooting and chimping to ensure that the exposure was ok.For the most part I was doing well but I would have realized a whole lot less PP had I gotten closer in camera.

I acknowledge the shortcomings but like RF finders, EVFs have their uses.

Oh sure. I'm not advocating abandoning EVFs. I'm all for technological improvements when and where we can make them. I think EVFs can and will be quite useful in certain circumstances. Some EVFs in use for high end cinematography are already quite good, and excessively expensive on a per-part basis. Those costs will come down, and they service their niches quite well.

My concern is that someday EVFs will ultimately replace OVFs.

There is this strange fervor over miniaturization and elimination of the mirror. Its like a fashion fad that just won't die. I don't quite understand it. Not one single mirrorless camera that I've ever held felt good in my hands. I feel cramped, I have to compress my hands in a weird way, and compress the camera and my hands against my face in an uncomfortable way. Miniaturization certainly has its uses in some areas...we don't want our processors to take up warehouses worth of space, so miniaturization does wonders for computing chips. A reduction in weight is useful as well, however not at the cost of having to work contortionist magic on my hands in order to hold a camera to my face. IQ aside, unless some pros have figured out the magic of one-handed photography, I cannot fathom what it is about these microscopic little cameras that has everyone so radically excited, even raving.

Yet...that's the trend. Fad or otherwise, I do have some honest concerns about EVFs and MILCs replacing good old OVF DSLR cameras WAY too soon. I could possibly get used to a mirrorless camera for landscapes...hell, 90% of that work is done with a tripod and a remote shutter release. But wildlife? Birds? Any kind of action whatsoever? Ergonomically, mirrorless cameras (at least as they are designed today), in their diminutive size with their lackluster EVFs, are an utter disaster....

1175
EOS Bodies / Re: New high resolution camera
« on: November 11, 2013, 11:46:48 PM »
I don't agree with this.

I know you don't, and you argue my examples when I show them, that is fine, you make your cjhoices for yourself and I'll make mine for me.

But I never questioned system resolution as a concept, I know full well the interplay of the elements within that system. We just come to different conclusions when looking at the images they produce, I don't care a fig for technical theories, just understanding why I see what I see.

Well, the example I've usually seen from you is the 7D vs. the 1D III, and I think your argument usually boils down to the fact that the AA filter on the 7D is fairly strong, thus diminishing the value of the 7D. I won't deny that a strong AA filter throws another factor into the mix, and it is a factor to take into account when actually measuring different devices. Even so, the use, or not, of an AA filter isn't a reason to stop pushing megapixel count/spatial resolution. My theory always assumes "all else being equal"...in which case the AA filter would be tuned to provide similar results around nyquist for any given sensor resolution.

I don't deny that it is important to use empirical data as well, however empirical data can and is often interpreted differently. It's a subjective measure, and how the data is interpreted, according to what criteria, and by whom, are all important factors in normalizing empirical results. Personally, I see a meaningful, if not "ideal", improvement in resolution with the 7D over the 1D III in your past visual examples, you do not... That is an important discrepancy, and just because the data is yours does not inherently invalidate the observations of others. I have very good 20/10 vision with my corrective lenses, and perhaps that plays a role. If the 7D had a weaker AA filter, the difference would likely be even more pronounced. One could also perform a test with the AA filter removed from both cameras (thus eliminating the additional factor), and I think the difference in spatial resolution would be quite clear in that case.

Your argument is usually perceptual (subjective), where as I try to make mine objective. Perceptual/subjective arguments, while not invalid, are hard to use as a viable basis for comparison because of the very fact that they can be interpreted differently in the absence of normalization. You see the 7D as having no visual benefit over the 1D III...I see the 7D as indeed having a visible benefit over the 1D III, if not quite as much as theory would have predicted...all using the exact same source images that you yourself produce. That is a war neither of us will win, and one which doesn't help anyone else understand the fundamental value of having a higher resolution sensor.

A 24mp APS-C sensor would arguably demonstrate an even greater lead over the 1D III...I'd be very curious to see you perform a visual comparison of say a D7100 vs. the 1D III, or even the 5D III that was identical to your test of the 7D and 1D III. I'd wager the D7100 clearly outperforms either Canon camera in the realm of final resolving power (spatial resolution).

I'm sorry if my replies frustrate you, but you often seem to be making the (subjectively based) argument that there is no value whatsoever to increasing megapixel count beyond the point where Canon currently is (~20mp APS-C, ~24mp FF). From an objective standpoint, there most definitely is, and I think it is important that people understand that. All else being equal, you don't lose anything by moving to a higher resolution sensor, and in fact you almost always gain something.

Subjectively, images from the D800 (at least at lower ISO/in good light) are superior, often vastly superior, to anything that you can get out of any Canon camera on the market right now. As a Canon fan, I don't really like to give a bone to the competition, but in this case, both subjectively and objectively, a higher resolution sensor most definitely has something to offer...and in a clearly visible, empirical way.

1176
EOS Bodies / Re: Why are DSLRs so Big?
« on: November 11, 2013, 07:25:20 PM »
As Canon stated, they were able to reduce the size of the SL1 by developing a new package for mounting the sensor as well as further miniaturization of the electronics.  Its small enough now so that I find it difficult to use.
How big of a LCD display did your canon F1 have ?  How many buttons?  Not to mention joystick and control wheels.  You can combine them down to fewer controls, and with touch screens, maybe some of them can go away.

Even with a large touch screen, the controls would never be as convenient or reliable, and likely never as quick, as with physical dials and buttons. There is something to be said for having a large camera body with large physical controls...you have the ability to memorize button placements, button press sequences, dial rolls by notches, etc. allowing you to almost entirely automatically reconfigure a DSLR on the fly via. procedural memory, allowing the rest of your mind to focus on the art. I can't imagine ever being able to achieve that with a touch screen...especially when my face is pressed up against the camera body.

1177
EOS Bodies / Re: Patent: A Pellicle Mirror by Canon
« on: November 11, 2013, 07:22:32 PM »
... Are they there yet? No! But they are getting closer and how long will it be until EVF is superior to optical....

Regarding the emphasized part above...I would say never. I think an EVF could get very close to being "as good as" an OVF, but an optical viewfinder is ultimately only going to be limited by the viewers eyes. There is going to be no limit on dynamic range, only the lens will limit resolving power, it will always work in any light level (i.e. I use my OVF to find stars when doing astrophotography...stars, which have about 0.0020-0.0025 lux), and always updates instantaneously when your scene changes. No matter how you slice it...an EVF will never be "superior" to those things.

Given that an EVF is ultimately dependent upon the sensor for low-light sensitivity, barring some unbelievably radical change in how low light sensitivity is achieved, I don't foresee an EVF ever supporting astrophotography...even with 100% Q.E., more than half the stars in the night sky that are visible with an OVF are going to be lost to noise with an EVF. Dynamic range will never be infinite with an EVF, as the sensor's DR will never be infinite. For an EVF's pixels to be invisible to an eye with 20/20 vision, they would need to be so small that they would filter out a moderate amount of red light, and to be invisible to an eye with 20/10 vision, they would need pixels so small that they would filter out most red light.

I'll probably have no choice, at some point in the future, but to switch to mirrorless. When that day comes, I'll do it as begrudgingly as a human being can begrudge...as from a technical standpoint I do not see how an EVF will ever even be as good as an OVF, let alone superior to one. Personally, I am hoping the classic slap-happy, noisy DSLR lasts for another 50 years...after which point I'll probably be dead, and will no longer care.  :P ;D

1178
EOS Bodies / Re: Patent: A Pellicle Mirror by Canon
« on: November 11, 2013, 07:09:55 PM »
They won't be much smaller, the geometry for a pellicle mirror is the same as a swinging mirror, they should be lighter and less complicated.

However, the "issue" for pellicle mirrors was always durability and light loss, the silvering had to be on the frontside of the mirror so was very delicate, and even the best lost the film about 1/2 a stop, also the light going up to the viewfinder is lost to the exposure. Now if they have come up with an electronically switching mirrored surface that is silvered on the backside they have cracked it and I for one, would find that more interesting than the EVF's around so far.

Totally agree. Some kind of piezoelectric pellicle mirror would certainly tickle my fancy! I'd pick up one of those, for almost any cost, before even looking at a mirrorless with an EVF. I wonder if it is possible, though...to use some kind of electrostatically activated mirror that doesn't result in any light loss when deactivated for exposure...

1179
EOS Bodies / Re: New high resolution camera
« on: November 11, 2013, 07:03:00 PM »
That would all be well and good if you achieved close to those 36MP in actual use. But Nikon, and forget Sony, don't come close.

DxO ratings have been widely discredited, but their measurements are considered by all to be accurately made and honest, look how poorly the D800/E actually does, http://www.dxomark.com/Lenses/Camera-Lens-Ratings/Optical-Metric-Scores so how does a 36mp system resolve a mere 2-4mp more than a 21-24mp system?

In most situations, even with the best glass made for 135 format cameras, you are not going to achieve anything like the resolution your sensor numbers suggest once you go over the mid 20's, factor in AF, less than optical bench test level support (forget hand holding), perfect illumination and contrast and a billion other variables encountered in actual image taking and the "benefits" of these oft touted and demanded sensors become useless.

I believe Canon know this, this is the reason they have so far "settled" on 18mp for APS cameras and mid 20's for ff cameras, they are smart and know the next level advances are not in the mp numbers, the advantages as demonstrated by the D800/E are just not there yet.


I don't agree with this. Resolution is a product of all system components, not just the lens or just the sensor. The D800 clearly produces images with better resolved finer detail. No, you certainly don't get a linear increase in resolution as sensor pixel count scales up, but the difference between a 24mp FF sensor and a 36mp FF sensor is certainly quite clear to the naked eye.

This is because it is a misnomer to assume either that a lens "outresolves" a sensor or a sensor "outresolves" a lens when discussing the final result. The simplest approximation of final output resolution is to take the root mean square of the components involved. Assuming a "perfect" (i.e. diffraction limited) f/4 lens that resolves 170lp/mm (~2.9µm blur circle), and a sensor that resolves 120lp/mm (~4.1µm blur circle), then the final output resolution is going to be ~100lp/mm.

Code: [Select]
outputRes = (1 / sqrt(lensBlurCircle^2 + sensorBlurCircle^2)) / 2
A sensor with lesser resolution, say 100lp/mm (~36mp FF) and a sensor with higher resolution, say 150lp/mm (hypothetical 78mp FF), using the same exact lens the final output resolutions are going to be ~86lp/mm and 113lp/mm, respectively. Both are meaningful differences...a 100lp/mm sensor resolves about 16% less than a 120lp/mm sensor, and a 150lp/mm sensor resolves about 13% more.

We could extrapolate further. Assume someone develops a FF DSLR sensor with 1µm pixels (similar to the pixel sizes in compact cameras and phone cameras). Such a sensor would have 864mp. Completely useless, right? Well, using the same formula above for the same lens again, the output image would have about 162lp/mm...and increase of over 43% over our previous hypothetical 78mp sensor.

You can always gain more with a higher resolution sensor. There is eventually a point of diminishing returns...our hypothetical 864mp FF sensor is definitely getting there as well...as no matter how high you push the megapixel count, you can never resolve more than the lenses 170lp/mm. When diminishing returns kick in, you need a more perfect lens, and eventually a more perfect lens at a wider aperture (to resolve more than 170lp/mm). Given the difficulties of achieving both perfection and a wider aperture, I suspect once FF sensors hit the 1.5-2µm pixel pitch mark, there won't be any reason to go any farther unless some kind of hardware pixel binning is employed. That said, I do most certainly think we can do much better than 36mp for FF sensors, and better than 24mp for APS-C sensors.

Now, all the theory aside...if you have a high res FF sensor paired with a lens that just can't keep up (i.e. it has excellent center performance but horrid edge performance, like say the EF 16-35mm f/2.8 L II), then you have to ask yourself: Why are you still using the 16-35 L II? A 78mp or even 864mp sensor will still resolve more in the center than a 23mp or even 36mp sensor, but the corners are always going to be crap regardless. Buy a Nikon 14-24 and the necessary Canon adapter, and slap that on your ultra high res FF camera to extract the most you can from the sensor, and push that final output resolution as high as possible.

1180
EOS Bodies / Re: SL1/100D vs EOS-M image quality
« on: October 30, 2013, 10:26:13 PM »
Check http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=458&Camera=835&Sample=0&FLI=0&API=2&LensComp=458&CameraComp=812&SampleComp=0&FLIComp=0&APIComp=2TDP's ISO 12233 crops for the 200/2.  They're shot RAW, converted in DPP with the same settings.


That link is broken. The text "TDP's ISO 12233 crops" is actually included in the URL, when I don't think it should be.

1181
EOS Bodies / Re: EOS 7D Mark II Spec List Surfaces [CR1]
« on: October 30, 2013, 10:24:22 PM »
I am not about to say pixel size is the most important factor, however I would say it is far from a "mostly irrelevant factor."

Let us not take this out of the context in which it was said. We were talking about noise and the large pixel fallacy. I also said that smaller pixels collect more information, that there are tech related factors, etc.

Ok, fair enough.

1182
I was seriously considering  the kenko,  but knowing this might be a possibility lead me right into the arms of  Canon.   pretty sneaky sis.

Also keep in mind that when using a Kenko on Canon, metering is off by one or two stops, depending on which TC you are using. You eventually pick up on that, but early on you'll find that most of your shots are overexposed. I still forget to compensate these days, which is why I finally just went and purchased the Canon TC instead...much less of a hassle having to always remember to change your exposure by an additional stop.

The real question is, is that slightly lower hassle worth twice the cost? The Keno DGX TCs are about half the cost of the Canon Mark III TCs...

1183
EOS Bodies / Re: EOS 7D Mark II Spec List Surfaces [CR1]
« on: October 30, 2013, 10:05:34 PM »
Full well capacity is really more a function of pixel area than pixel Q.E. Area is the defining factor when it comes to how much charge a pixel can hold. Increasing Q.E. might improve sensitivity, which is the rate at which photons convert to charge, but it doesn't do anything to increase the maximum charge (FWC) a pixel can contain. That is why cameras with larger sensors generally perform better than smaller sensors...they have historically had larger pixels.

No, larger sensors perform better (for a given exposure) because they are, well, larger. Pixel size is a secondary, mostly irrelevant factor.

Correct. I did read, and still remember, the article on equivalence. So, correct, assuming you are always using the full sensor area. There are situations where you don't, say cropping for detail. In which case, the part of my answer you did not quote applies...it's a tradeoff. I am not about to say pixel size is the most important factor, however I would say it is far from a "mostly irrelevant factor." It all just depends, and you make the various tradeoffs you have to in order to get what you need so service your own personal photography best.

In the end, one could often make the argument that neither pixel size nor sensor size really matters in the end anyway, as a more significant factor in final image quality is how you process, so long as the image output size is smaller than the input size (which is by and large the most common case these days with publishing occurring on the internet far more than it occurs in print in any form).

1184
EOS Bodies / Re: EOS 7D Mark II Spec List Surfaces [CR1]
« on: October 30, 2013, 09:52:23 PM »
Fairly simple reason for this..... assuming the same technology for reading the charge, if you make the photosite with twice the area, it will collect twice the charge, and the accuracy of the reading will be twice as accurate.....but this is only true until saturation is reached.... and that's why FF is so much better in poor light with less of an advantage in good light.


Wrong, the D800 is as good as the D600. Pixel size is an almost irrelevant factor, sensor size is the main factor (for the same exposure). You are confusing what happens at pixel level with what happens at image level.


Here is my logic......
Let's say that you have two cameras, one with pixels twice the size of the other. We assume a 16 bit a/d converter. We assume that all the circuitry is of the same technology.

You take a picture of the same scene with both cameras. In the first camera there are 0 units of charge in a dark pixel and 500 units of charge in a bright white pixel... Gain is applied (multiply by 128, either digital or analog) and you end up with a 16 bit number where the last 8 bits are noise.
In the second camera there are 0 units of charge in a dark pixel and 1000 units of charge in a bright white pixel... Gain is applied (multiply by 64, either digital or analog) and you end up with a 16 bit number where the last 7 bits are noise.


That is noise per pixel, not per area. The signal in the first case will have weight 1/2 of that in the second in the final image. So you multiply by 128 but when you resize to the final output image, you divide that by 2.


Assuming you resize.

@Don: Pi is referring to Equivalence. He has brought it up in prior threads. The source of the theory is actually very good. Read this: http://josephjamesphotography.com/equivalence/index.htm. It might clear some things up.

1185
EOS Bodies / Re: EOS 7D Mark II Spec List Surfaces [CR1]
« on: October 30, 2013, 05:43:55 PM »
Doesn't larger FWC allow more DR?  Of course, as I type this I'm thinking about the D800 its DR.  Ah hell, I'm going back to using the green square mode and not thinking about this crap.

Only really at the lowest ISO setting, however to get more usable DR than the best sensors offer today, you would also need to increase bit depth. The best sensors on the market (Exmor) get around 13.2 stops of DR at the lowest ISO setting. You might be able to push that to 13.8 stops and still use 14 bit data, but to get any meaningful increase, you would need to use full 16 bit data.

Full well capacity is really more a function of pixel area than pixel Q.E. Area is the defining factor when it comes to how much charge a pixel can hold. Increasing Q.E. might improve sensitivity, which is the rate at which photons convert to charge, but it doesn't do anything to increase the maximum charge (FWC) a pixel can contain. That is why cameras with larger sensors generally perform better than smaller sensors...they have historically had larger pixels.

It's a trade-off, though. While those larger pixels have less noise, they also reduce spatial resolution. If you have a FF sensor with 8µm pixels and an APS-C sensor with 4µm pixels, the FF sensor will have a higher FWC and therefor less noise, but also half the resolution.

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