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02-10-2015, 09:32 AM   #46
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If I bought a FF digital I would no longer have to make the calcualation of which lens to use on my film camera to get an approximate image that I do on the digitl. I figure that should save me close to 10 seconds in my lifetime and as long as I am making more than $90 grand per hour for my photography it would pay me to go FF just based on this alone.

02-10-2015, 10:20 AM   #47
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QuoteOriginally posted by kooks Quote
Does anybody knows how is the ISO tolerance with Nikon when somebody use the Crop Mode?? i know that the ISO at the D810 goes up to 2855 +/- without any mayor noise but.. what about if it is use in crop mode? is it reduce to 1200 as most APSC ?
I've spoken to guys in a local FF Nikon click a bunch of times. One of them outright told me his D800 cropped to 1.5x has less noise than the D7000 with all factors being the same. I don't know how much less. I usually am more critical with information from people who don't take good photos but all of these guys seem to take great photos.

What I really want to know is, since FF camera pixels are more efficient, is is going to improve the autofocus with all other factors being equal? It seems to me all FF users prefer their FF autofocus to their crop cameras. I don't know if FF cameras simply have more expensive autofocus components or is is a litte bit of both.

---------- Post added 02-10-2015 at 12:22 PM ----------

QuoteOriginally posted by clackers Quote
Not this again!

The noise level and exposure will be the same as in the FF mode.

It's just a *crop* of such a picture.

The pixel pitch, electronics and heat dissipation design are the same.
That would seem to make sense to me too. I will tell you what, we are going to find out won't we?

http://home.comcast.net/~NikonD70/Charts/PDR.htm#D800,D800(dx)

Actually when I look at some of the other Canon cameras compared to the Nikons, (I have my opinion of them) it looks like there is probably some noticable difference.

Last edited by traderdrew; 02-10-2015 at 10:47 AM. Reason: adding a graph
02-10-2015, 02:56 PM   #48
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QuoteOriginally posted by clackers Quote

If you think 4% of the noise pixels suddenly turn to 8%, or that stops of dynamic range are lost in the crop, I want some of what you're smoking!
I smoke the same stuff DXOMark smokes, or any sensor engineer who's ever written about the subject, or anyone who's ever bothered to crop and look at the results, FF or otherwise.

The resulting image noise is more obvious, and the image DR is reduced when the image is cropped and enlarged. That's just a fact, I'm afraid.

Nothing changes at the pixel level, which (I think) is what continues to confuse you.

I suggested before that you do the experiment yourself - crop an aps-c (or any) image at 1.5x, 2x, and 3x, look at the results on your display and in print at the same size. Is the noise more visible with each succeeding crop?

Look at the link Brianr provided. Here's an interesting link where this is discussed, where the sensor engineer and creator of the sensorgen site tries to explain the effect, and here's another that talks about the effect on DOF: here.

Here's Bill Claff's measured results based on raws from each sensor - the "DX" designations means 1.5x crops:




But really there are dozens or hundreds of links like that if you're interested in researching the subject.

.

---------- Post added 02-10-15 at 04:14 PM ----------

QuoteOriginally posted by traderdrew Quote
I've spoken to guys in a local FF Nikon click a bunch of times. One of them outright told me his D800 cropped to 1.5x has less noise than the D7000 with all factors being the same. I don't know how much less.
Not much less. You're actually hard-pressed to see any difference between a D7000 native and D800 cropped (I own D800 now and owned a D7000 for about a week.)

QuoteQuote:

What I really want to know is, since FF camera pixels are more efficient,
They're not The pixel/sensor efficiency has everything to do with the level/age of the technology involved.


QuoteQuote:
...is is going to improve the autofocus with all other factors being equal? It seems to me all FF users prefer their FF autofocus to their crop cameras. I don't know if FF cameras simply have more expensive autofocus components or is is a litte bit of both.
There is theoretically going to be more margin for error with most FF combos lens/sensor because the act of enlargement is going to put the aps-c combo at a disadvantage, but personally I think the FF bodies tend to get better asics, more processing capability and the AF point tolerances lower and precision might be higher. The better AF system usually is folded ito the overhead and the customer pays for it happily

This is something IMO we should wish for with Pentax, BTW. Don't skimp on AF any longer, we'll gladly pay a small premium for the best AF. It's going to be a discerning factor from MILC for a while (PDAF,) lets take advantage of it.

.

Last edited by jsherman999; 02-10-2015 at 03:19 PM.
02-10-2015, 05:40 PM   #49
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QuoteQuote:

That would seem to make sense to me too. I will tell you what, we are going to find out won't we?

Photographic Dynamic Range versus ISO)
Here's the D800 cropped vs. uncropped from that link. Surprise, surprise



02-10-2015, 10:17 PM   #50
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QuoteOriginally posted by jsherman999 Quote
The resulting image noise is more obvious
.

No, what's obvious is the scaling - there are now less pixels for the same output - we mentioned this enough times in the discussion, not sure why you didn't get the memo!


But if every tenth pixel was chroma noise in the uncropped pic, it's still one-in-ten in the crop.


That's what SNR is - a ratio of nine signal pixels to one noise - and cropping hasn't altered that.


Now I want to hear your argument for why dynamic range is reduced by cropping.
02-11-2015, 02:53 AM   #51
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QuoteOriginally posted by jsherman999 Quote
The resulting image noise is more obvious

Really? Enlarging an image more makes the noise/grain more obvious? Well, I'm astounded.

Next thing you'll be telling me that using a 500mm lens handheld at a two second exposure will make things look blurry. And that the reason why the bear looked angry when I took a photo of it in the woods the other day was because I was intruding on its toilet time.
02-11-2015, 07:40 AM   #52
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QuoteOriginally posted by jsherman999 Quote

There is theoretically going to be more margin for error with most FF combos lens/sensor because the act of enlargement is going to put the aps-c combo at a disadvantage, but personally I think the FF bodies tend to get better asics, more processing capability and the AF point tolerances lower and precision might be higher. The better AF system usually is folded ito the overhead and the customer pays for it happily

This is something IMO we should wish for with Pentax, BTW. Don't skimp on AF any longer, we'll gladly pay a small premium for the best AF. It's going to be a discerning factor from MILC for a while (PDAF,) lets take advantage of it.

.
With the new 150 to 450mm lens coming out, they better work on improving their autofocus. I'm not going to say anything bad about the autofocus of the K-3. It's better than the K-5 models. It's just that wildlife will push a camera to its limits in many ways. At least good bird photography does.
02-11-2015, 07:45 AM   #53
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QuoteOriginally posted by kooks Quote
So we can expect that the Crop Mode will behave sort of like spects of the K3 +/- ..
Only if the sensor in the new FF model matches (in crop mode) the pixel count in the k-3, which will have to be higher 40M+.

02-11-2015, 12:51 PM - 1 Like   #54
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QuoteOriginally posted by clackers Quote


That's what SNR is - a ratio of nine signal pixels to one noise - and cropping hasn't altered that.


Now I want to hear your argument for why dynamic range is reduced by cropping.
Cropping alters nothing at the pixel level - the act of enlarging the crop to the same display size is what makes the image noise more apparent. I'm running out of ways to deliver that memo to you

By the way you seem to think you're arguing against me, against something radical I alone am proposing. Why do you think that? Have you just decided to not follow the links I provided, not look into the vast amount of external source material, not believe DXOmark, sensorgen, etc?

The measured data graphs I included earlier in this thread - do you think I made those up? How do you explain them if not? Do you have other data that refutes them?

Here, specifically to your question, again: DR reduced by cropping/enlarging?

That ^ same question has been asked and answered several times that I'm aware of on dpreview, even here I think. That's just the easiest to find with a simple search.

Please, if you're not just trolling, take the time to read the external sources and discussions if you don't want to take my word for it. (If you don't like reading threads, Bill Claff and Bob Newman ("bobn2") do respond to emails/PMs on dpreview, and Falk Lumo ("falconeyes" in that thread) is active on this forum.)

.

---------- Post added 02-11-15 at 01:54 PM ----------

QuoteOriginally posted by Dartmoor Dave Quote
Really? Enlarging an image more makes the noise/grain more obvious? Well, I'm astounded.

.
I know you're being sarcastic, but some folks, including apparently clackers, *are* astounded by that.

---------- Post added 02-11-15 at 02:01 PM ----------

QuoteOriginally posted by aleonx3 Quote
Only if the sensor in the new FF model matches (in crop mode) the pixel count in the k-3, which will have to be higher 40M+.
It would need to be 54MP. (I think it's going to be 36MP though, so a crop will match the K-5. Not too shabby in my book.)

Last edited by jsherman999; 02-11-2015 at 01:03 PM.
02-11-2015, 06:00 PM   #55
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QuoteOriginally posted by jsherman999 Quote
Cropping alters nothing at the pixel level - the act of enlarging the crop to the same display size is what makes the image noise more apparent.
But this is 'Captain Obvious' stuff.

Here we agree - "apparent".

Brian and I have already discussed this, many, many posts ago. :-)

Losing pixels is fine if they can't be rendered by the output resolution. Enlargements beyond a point will always make a difference - the MF and 67 guys and gals benefit from this.

Last edited by clackers; 02-11-2015 at 06:13 PM.
02-11-2015, 06:33 PM   #56
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Sargeant Obvious

QuoteOriginally posted by clackers Quote
But this is 'Captain Obvious' stuff.
I'm not so sure. If it were captain-level-obvious you wouldn't have barged in here to refute it in the first place.

Also, you're not the only one who makes this mistake. Almost every thread on dpreview where this is discussed has at least one poster saying a variation of "But the pixels don't change just because you crop, you guys are really stupid!"

After some careful explanation, if it 'takes', that poster will offer something like "Of course if you change the size after cropping you see more noise! Duh!", describing the general case that all these DXOmark etc measurements are based on and what photographers actually do as if it were some special case.

Kinda like, "Of course the Audi A8 is faster than the Chevy Lumina, but only if you're in the same gear! If you drive the Lumina in 4th gear and the Audi in 1st, different story!"

02-12-2015, 08:01 PM   #57
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QuoteOriginally posted by jsherman999 Quote
I'm not so sure. If it were captain-level-obvious you wouldn't have barged in here to refute it in the first place.

???

You said it yourself, Jsherman.

Cropping only changes resolution, it changes *nothing* at the pixel level, so don't go inventing 'apparent noise' or 'apparent DoF'.

Those are not the photographic definitions.

And I still want to hear why you think dynamic range is altered in the crop.

Not 'apparent DR', either, thank you ... that would be apparently unconvincing!

Last edited by clackers; 02-12-2015 at 08:33 PM.
02-13-2015, 12:39 PM   #58
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OK have to jump in, my take on all this:

I put my HD DA 1.4X on my 16-50 and my 60-250 and shot a roll of 35mm film. The FOV comes out close to what I get on my K5iis without the converter but because I am using a longer lens to get that FOV there is more detail. Also no need to use the crop option or buy new lenses. With the exception of 16mm and wide open that had a little shading on the corners all the pictures came out great with no vignetting. So if you get more detail to the sensor for the same FOV and you have more MP its a win win, just need to get the 1,4 converter if you don't have it.
02-13-2015, 01:21 PM   #59
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QuoteOriginally posted by clicksworth Quote
All these years we have been struggling with the equivalent focal length going from film to APC. Now we have to struggle it the other way. How about making it nice and simple. It will look the same as it did on film! The equivalent focal length will be exactly what it says on the lens.
This precisely. Yes, this camera will be a different experience altogether if you are not used to 135mm. If you'd like to get used to it and understand the change with your own eyes, simply go out and pick up a Pentax film body and attach your K-mount lens of choice. It's a different modality, and IMO a welcome one. I personally like the options.

If you'd really like to see the difference put a 50mm on both your DSLR and film body... You'll note that on the film body you can literally leave both eyes open because the FOV is nearly identical to what you eye naturally sees. Then look through the DSLR and notice the narrow field and the perceived magnification that takes place.

(and when I say "you" I don't mean just you clicksworth. speaking generally)
02-13-2015, 01:51 PM - 1 Like   #60
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QuoteOriginally posted by clackers Quote
???

You said it yourself, Jsherman.

Cropping only changes resolution, it changes *nothing* at the pixel level,
Of course it changes nothing at the pixel level. Think that's the third or fourth time I've said that in this thread alone. It doesn't need to for the image quality to be altered by enlargement.

I think you've caught yourself in a contradiction, by the way. If cropping/enlarging can somehow "change resolution", why can it not "change noise"?


QuoteQuote:

And I still want to hear why you think dynamic range is altered in the crop.
From 1) experience enlarging crops, 2) confirmation from sites like DXOmark and sensorgen and Bill Claff, which also provide a mathematical measure of how much DR is affected by magnitude of crop and subsequent enlargement.

I see you didn't bother to read the links I provided or look at the graphs I provided, again, or provide any contradictory sources or data. (smugness != data. )

At this point I have to assume you're trolling.

.

Last edited by jsherman999; 02-13-2015 at 02:55 PM.
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