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05-18-2011, 11:18 AM   #166
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QuoteOriginally posted by LFLee Quote
hm... no one admit because they can't afford a FF?

I think if Pentax have a FF, I will go for it. It would have to be around $2000 though to make it affordable for me.

Lee
I understand why Pentax isn't making a FF camera, but if they made one for $2000, I'd buy it ---- JUST FOR THE VIEWFINDER!

05-18-2011, 11:27 AM   #167
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QuoteOriginally posted by Marc Sabatella Quote
But if your primary consideration is maximizing DOF and you're willing to sacrifice all else to get there - and this is what the arguments in favor of APS-C over FF have basically amounted to - then indeed, a smaller sensor still is better. I am dead serious about that.
Not *all*; I only beat that particular horse so much because it really is *less* DOF, all things being equal, not "more control over DOF" as it's been characterized. Hyperbole about image destruction ( the LTDs are often still sharper at f16 APS-c than many other commonly used lenses are in the first couple of stops, so it *is* hyperbole ) notwithstanding, you don't get *more* DOF with FF without *changing the standards you're measuring by*.

But I've also pointed out that with the same MP, crop sensors provide greater detail at the same focal length, making them "natural" for macro and long-lens work (as long as you get enough light to provide sufficient signal-to-noise ratio). But you didn't particularly oppose that argument, so it's not seen much column space

QuoteQuote:
Not at all. Again, you completely misunderstand me. I use APS-C, and you couldn't *pay* me to trade it in for FF. I totally get why most people prefer APS-C - I'm one of those people. But I also like to make sure people are getting their facts straight about what the tradeoffs actually are.
Woah, woah, there. You *can* pay me to use FF! Just in case anyone is offering... LOL. Provided there's enough pay

Like I said, I miss the viewfinder.
05-18-2011, 12:04 PM   #168
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QuoteOriginally posted by normhead Quote
You're sounding a little desperate dude. Maybe you should let this go. your point is pretty much insignificant. Your 99% of photographers, you made that up.. in the same way you embellish the importance of FF over APS-C. You're framing the argument in a way that gives way to much importance to things of negligible effect.
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Norm, I think you'll find that Marc has been consistent in his statements that he much prefers aps-c, at least at the current prize/size combos the FF offerings come in. He tends to be an advocate for the facts, not any particular format/body/lens, etc.

Also it should be stated that the FF-centered forums are full of ex large-format folks (like yourself and Steve) who do like the digital FF format quite a bit. It does hit a sweet spot for some when you consider what the 'large' alternatives are - LF film, MF film, MF digital, digital backs, or aps-c and the smaller formats.

FF digital offers a compromise they are more than happy with when it comes with all the modern advantages in workflow and instant feedback digital brings.



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Last edited by jsherman999; 05-18-2011 at 12:24 PM.
05-18-2011, 12:22 PM   #169
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QuoteOriginally posted by jsherman999 Quote
Norm, I think you'll find that Marc has been consistent in his statements that he much prefers aps-c, at least at the current prize/size combos the FF offerings come in. He tends to be an advocate for the facts, not any particular format/body/lens, etc.

Also it should be stated that the FF-centered forums are full of ex large-format folks (like yourself and Steve) who do like the digital FF format quite a bit. It does hit a sweet spot for some when you consider what the 'large' alternatives are - LF film, MF film, MF digital, digital backs, etc, or aps-c.

FF digital offers a compromise they are more than happy with when it comes with all the modern advantages in workflow, instant feedback, etc digital brings.
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Even though we disagree about some things here, I think you and Marc have been very rational and consistent.

I understand I come from a different perception of the process than many people. I come from a place where every media I could record an image in out-resolved the final output media significantly 99% of the time; 4x5 was primarily useful for control of the focus plane, parallax, etc, not because the larger image was necessary. 6x6 was the go-to, and 35mm was a tool for when you needed to work fast and light.

I haven't - and still don't - oppose the assertion that if a given photographer *likes* FF better, then FF is a better solution for that photographer. I *do* oppose the insertion of empirical measurement as a function of artistic value.

I also oppose the blanket statements because they simply aren't true. It's stated that FF has higher signal-to-noise ratio - which is true, but only if the sensor sites are larger. If, as some have, the sensor sites are the same size, the signal-to-noise ratio advantage disappears. It's stated that FF has 'better IQ', but that's *only true if we're comparing the same generation of sensor*. It's stated that "MPixels doesn't matter" - which is patently false - such a statement implies that, say, a 6x6cm image composed of 100 pixels (10x10) is going to have a higher IQ than, for example, a 30x30mm image composed of 10000 pixels (100x100) - absurd on the face of it. There *is* a min/max SNR/pixel density per technology. The K-5, for instance, produces significantly lower read noise than some FF sensors with MUCH lower pixel density ( I don't know how the new sony sensor achieves this, so can't observe details ).

To make an observation of comparative IQ, the question must be asked: "Which camera, which lens, what aperture, what ISO, what shutter speed, what lighting conditions, and what output size and media?" For nearly all values of all of those things, the results are *indistinguishable*. Even so, this will still not tell you whether the resultant image is *good photography*.

If we'd never had "full frame" DLSrs, we'd have a 33mm f1.2 for APS-c for ~$600, and the results would ALSO be indistinguishable from current FF output even in the edge cases.

05-18-2011, 12:48 PM   #170
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I feel like to chime in if you excuse me. Watching Pentax' lens investments I think I've completely understood and second Pentax FF policy which is: why stuck with 24x36mm? Thats a film era old fashion concept. Camera producers had to fulfill the digital gap for their expensive 35mm lense lines-ups with SR, thats why they are producing digital FF cameras. Pentax also has produced an FF camera, don't you see it? it's there, 645D, you can get less DoF, more DoF, more resolution, if you are bothered with the excess area than 24x36 mm, you can crop and voila, you have an exact 24x36mm sensor, what else do you want? One APS-C camera line for ent-prothusiasts and the other one is medium format, I don't think 645D has considerably more weight, size and handling issues comparing with flagship of the FF cameras, D3x.

End of story, thanks for bearing with me.
05-18-2011, 12:54 PM   #171
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QuoteOriginally posted by Marc Sabatella Quote
[...] Well, yes, but math that somehow manages to simplify the factors that an ordinary DOF calculation would need to know. It may well be true that as focus distance approaches hyperfocus distance, the traditional DOF formulas fail. I've seen that suggested. I haven't seen it *proven*, though. I have a degree in math, so I'd be able to follow such a proof were one posted, but I'm not sufficiently interested to actually invested the time that would likely be required. [...]
YES! Some online calculators use the simplified equations which become increasingly inaccurate as distance gets closer than hyper-focal distance. I think someone has confused that fact with "as focus distance approaches hyperfocus distance, the traditional DOF formulas fail", something I've never heard before. Maybe I need to get out more

This online DOF calculator Online Depth of Field Calculator uses the formulas presented at Depth of field - Wikipedia, the free encyclopedia

This is pretty good reading: The DOF equations

And I'm posting this link again, to pertinent Zeiss pdf: Depth of Field and Bokeh

A worthwhile exercise in my experience is to write a spreadsheet macro...



Someone mentioned the relativity of DOF calculations to final print size and viewing distance. (Bravo!!!) It is the Coc number in the DOF equations that accounts for the DOF relativity to sensor size. DOF calculations for different size sensors with the same lens need correct Coc entry to give identical DOF numbers at proper distances -- i.e. that calculation would reveal the settings for: with the same lens on two different sensor sizes, produce 8x12" prints from each camera, with identical framing and identical DOF.
05-18-2011, 01:00 PM   #172
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QuoteOriginally posted by jstevewhite Quote
It's stated that FF has 'better IQ', but that's *only true if we're comparing the same generation of sensor*. It's stated that "MPixels doesn't matter" - which is patently false - such a statement implies that, say, a 6x6cm image composed of 100 pixels (10x10) is going to have a higher IQ than, for example, a 30x30mm image composed of 10000 pixels (100x100) - absurd on the face of it. There *is* a min/max SNR/pixel density per technology. The K-5, for instance, produces significantly lower read noise than some FF sensors with MUCH lower pixel density ( I don't know how the new sony sensor achieves this, so can't observe details ).

To make an observation of comparative IQ, the question must be asked: "Which camera, which lens, what aperture, what ISO, what shutter speed, what lighting conditions, and what output size and media?" For nearly all values of all of those things, the results are *indistinguishable*. Even so, this will still not tell you whether the resultant image is *good photography*.

If we'd never had "full frame" DLSrs, we'd have a 33mm f1.2 for APS-c for ~$600, and the results would ALSO be indistinguishable from current FF output even in the edge cases.
Dude, you seem to be especially obstinate without any hope to understand the expanation why the FF systems have actually better IQ. I got why some people here prefer APS-C due to its lower cost, lighter APS-C only lenses, etc. But I'm losing my faith to mankind when people like you does not show any comprehension about the subject.
First, I've mentioned already we should consider not the bodies alone but the (body, lenses) system. We also should not compare lens on FF vs the same lens on APS-C which is pointless, but rather two different lenses which have the similar FOV. And the first problem raises for lens designers: how to manage to achieve the same resolution characteristic for the lens that has 1.5 lesser magnification ratio. This problem has no solution actually, since they can use the same approach for the FF too.
The second problem is the APS-C lens should have 1.5 less noticeable abberations, because the 1.5 crop perform about 1.5 «magnification». But, again, the same approach could be used for FF lens.
And the main problem is those APS-C lenses are unlikely to be produced: the prime optical design has already reached its perfection, there's no room for significant advance. So they would cost a fortune and would be twice as big as good FF's ones, sharing the same characteristics on FF
05-18-2011, 02:03 PM   #173
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Did you all know that FF is only a crop sensor??? Yes it is, it is crop sensor compared to MF. So if you really want "good"IQ froma sensor, get the 645D, as clearly FF is only a crop sensor

05-18-2011, 02:43 PM   #174
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Sometimes your equipment is too big.

.


I would like everyone reading this thread to take the time to watch this short video and report back here what you've learned! ---> My Instrument is Too Big.

(Don't worry, it's about cameras. Maybe.)


.
05-18-2011, 02:46 PM   #175
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QuoteOriginally posted by Emacs Quote
Dude, you seem to be especially obstinate without any hope to understand the expanation why the FF systems have actually better IQ. I got why some people here prefer APS-C due to its lower cost, lighter APS-C only lenses, etc. But I'm losing my faith to mankind when people like you does not show any comprehension about the subject.
First, I've mentioned already we should consider not the bodies alone but the (body, lenses) system. We also should not compare lens on FF vs the same lens on APS-C which is pointless, but rather two different lenses which have the similar FOV. And the first problem raises for lens designers: how to manage to achieve the same resolution characteristic for the lens that has 1.5 lesser magnification ratio. This problem has no solution actually, since they can use the same approach for the FF too.
The second problem is the APS-C lens should have 1.5 less noticeable abberations, because the 1.5 crop perform about 1.5 «magnification». But, again, the same approach could be used for FF lens.
And the main problem is those APS-C lenses are unlikely to be produced: the prime optical design has already reached its perfection, there's no room for significant advance. So they would cost a fortune and would be twice as big as good FF's ones, sharing the same characteristics on FF
Dude, you seem especially obstinate in your dedication to applying ideal concepts to real world scenarios where they don't apply. You continue to make assertions that would lead one to the counter-factual conclusion that, say, a 3MP sensor @24x36mm would record more detail than a 12MP sensor in 16x24mm. If you want to say [B]the same lens can record more detail on FF than on APS-c given the FF has more pixels than the APS-c[B] I will agree. That obviously doesn't translate to the generic case that *every* lens records more detail on FF than *every* lens on APS-c, even when the FF has more pixels. And if the lenses have the same FOV, and the APS-C and the FF have the same number of pixels, *and* the lens has a COC smaller than the pixels on the APS-C sensor, AND the light level is sufficient for appropriate SNR, the detail recorded will be essentially identical. And if all of those conditions are met, and the APS-c has MORE pixels, the APS-c will record MORE detail. This shouldn't be difficult to grasp.

There *are* limits for pixel density beyond which additional pixels don't add detail because the SNR drops too far to be useful, but (as the K-5 demonstrates) that's technology specific, and the max has not been reached yet.

There are other noise cancellation technologies on the horizon that will further change the game, increasing signal to noise ratio significantly even in smaller sensors.

Your assertion that no improvement remains in lens design is... well, misguided. It's true that we can design ideal lenses, but we can't manufacture them ideally. There *are* still improvements to be made in manufacturing of lenses that can yield increases in lens performance - that is, every lens made has a minimum COC greater than zero.

I'd like to see some support for your assertion that, say, a 33mm 1.2 designed for APS-c image circle would be twice as big as a 50mm 1.2 for FF. Everything I've read says that smaller image circle == easier to design and build, all other things being equal.
05-18-2011, 02:48 PM   #176
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QuoteOriginally posted by rhodopsin Quote
YES! Some online calculators use the simplified equations which become increasingly inaccurate as distance gets closer than hyper-focal distance. I think someone has confused that fact with "as focus distance approaches hyperfocus distance, the traditional DOF formulas fail", something I've never heard before. Maybe I need to get out more

This online DOF calculator Online Depth of Field Calculator uses the formulas presented at Depth of field - Wikipedia, the free encyclopedia

Someone mentioned the relativity of DOF calculations to final print size and viewing distance. (Bravo!!!) It is the Coc number in the DOF equations that accounts for the DOF relativity to sensor size. DOF calculations for different size sensors with the same lens need correct Coc entry to give identical DOF numbers at proper distances -- i.e. that calculation would reveal the settings for: with the same lens on two different sensor sizes, produce 8x12" prints from each camera, with identical framing and identical DOF.
It was from the Wikipedia article on hyperfocal distance that I got the equations I presented.
05-18-2011, 02:48 PM   #177
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QuoteOriginally posted by Macario Quote
Did you all know that FF is only a crop sensor??? Yes it is, it is crop sensor compared to MF. So if you really want "good"IQ froma sensor, get the 645D, as clearly FF is only a crop sensor
No, see, the 645d is a crop sensor from a "good" sensor - a 100mp 4x5 scanning back, for instance.
05-18-2011, 02:52 PM   #178
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QuoteOriginally posted by jsherman999 Quote
.


I would like everyone reading this thread to take the time to watch this short video and report back here what you've learned! ---> My Instrument is Too Big.

(Don't worry, it's about cameras. Maybe.)


.
LOL! That was a blast. I shot a lingerie catalog... actually, more of a glossy brochure-thing used by their seller to impress buyers ... on 4x5 once upon a time. The client insisted. It was fun. Once.
05-18-2011, 05:15 PM   #179
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QuoteOriginally posted by jstevewhite Quote
If, as some have, the sensor sites are the same size, the signal-to-noise ratio advantage disappears.
No, because the FF sensor is larger, so it has more photosites and equivalence comparisons imply maintaining the same FOV and distance from subject. If you scale down images to the same size (the way dxomark makes comparisons) then the extra photosites of the larger format will give you an equivalent effect to pixel binning.
05-18-2011, 05:29 PM   #180
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QuoteOriginally posted by Laurentiu Cristofor Quote
No, because the FF sensor is larger, so it has more photosites and equivalence comparisons imply maintaining the same FOV and distance from subject. If you scale down images to the same size (the way dxomark makes comparisons) then the extra photosites of the larger format will give you an equivalent effect to pixel binning.
Absolutely, but to achieve that you have to drop back to a lower effective pixel count; you might as well use the larger sensor sites and a lower MP sensor. This is where many people get the "megapixels don't matter" mantra, but it's really "megapixels *alone* don't matter". I'm just saying that you can *get* more detail with the FF by adding more pixels, but you have to give up some of that detail to get the DR back, or give up the DR to get the detail. Trade-offs, not a "slam dunk".

The point of that part of the exercise was to illustrate, anyway, that megapixels sometimes *do* matter. If you have a 12MP sensor, and I have a 16mp sensor, we have the same FOV and good lenses, and we both light our scene to sufficiently exceed the noise floor, then print them both full-frame on 8x10, the 16mp sensor will RECORD MORE DETAIL, even if it's a 16x24mm.
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