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02-24-2015, 01:54 PM   #211
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QuoteOriginally posted by Class A Quote
Sorry, but f/2.8 on FF is faster than f/2.8 on APS-C (assuming equivalent focal lenghts).

...

The meaning of "faster" is tied to DOF and exposure, not to a number that varies with the sensor size it is based on.
You can use whatever terminology you like, just expect people to be confused when your wurlitzers don't match how they're used in the standard voice recognition unicycle.

02-24-2015, 02:24 PM   #212
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QuoteOriginally posted by Class A Quote
And you'd be getting better IQ than shooting with f/7 on APS-C (for the same framing).

If you don't need the extra IQ boost then you don't need FF gear, however, FF is not just for shallow DOF.

The large format shooters of yore, often stopped down to f/64. They didn't choose the heavy, large format equipment to get shallow DOF shots.
I suppose you are right. I guess I'll find out when I own a full frame camera.

The question I have is how much of an image quality boost will a photographer really see? Is it the sort of thing you'll see at web sizes? Will you see it an 8 by 10? Or do you only see it if you print 36 inches on a side? I don't honestly know. When I am guessing crop or full frame looking at photos, I mostly do it based on depth of field. I can't honestly look at a Flickr photo and tell if it was taken by a D7000 or a D800. I'm sure there are experts here who can, I just haven't developed the eye for it, I guess.
02-24-2015, 02:58 PM   #213
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QuoteOriginally posted by BrianR Quote
Nether comparison is better than the other, they're just different (though I also don't understand how Norm's example is supposed to simulate a ff/aps-c DoF comparison).
So we have three comparisons:
  1. Apples to Apples
  2. Apples to Oranges
  3. Apples to Lemons
If you are saying, neither is better than the other, then I have to politely disagree.
Some people may be smart enough to compare apples to oranges and still know what is happening, but for most it is better to compare apples to apples.

QuoteOriginally posted by BrianR Quote
I beg of you to stop trying to enforce an 'apples to apples' comparison as you call it, it's A way to compare, not THE way.
I'm not trying to "enforce" anything.

Sometimes, if someone posts something that is incorrect, I try to point out why it is incorrect. That's done easiest with an "apples to apples" comparison. The wrong conclusions people arrive at ("A larger sensor has better light gathering abilities" and other such myths) tells me that their "apples to oranges" comparisons don't work.
02-24-2015, 03:01 PM - 4 Likes   #214
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It works for 'f/8 and be there' too

QuoteOriginally posted by Rondec Quote
I understand that you think that shallowness of depth of field is the goal of photography
Argh!

I hate when people misread what I say and put words in my mouth.

Shallow DOF is not the 'goal of photography.'

What I said was that the majority of the time for my shooting, the DOF either doesn't matter (subject far enough away, at hyperfocal, etc)
or it's beneficial (subject isolation). The times when I need to stop down past the point where I'm giving up DR/SNR are few and far between, for me. Even when I'm trying to isolate the subject, the environment is nicely represented without being harsh/distracting:

Here are some shots that (maybe) show what I mean when I say "DOF doesn't matter or shallow DOF is beneficial"

180mm f/2.8

180mm f.2,8, 50mm f.1.8

180mm f/2.8, 32mm f.2,8 (tamron 28-75 2.8)



Even for WA, or landscape. I'm usually shooting things where I'm taking advantage of hyperfocal or very-expanded DOF, and I usually am shooting at f/8 for those situations on both aps-c and FF. I get 'enough' DOF in both cases, in fact for that type of shooting I can't usually even see any difference in DOF, and I can take advantage of the better SNR/DR on the larger format then.

20mm f/8 (always shoot my 15ltd at f8 - this 20mm on FF gives me another stop, these are just to show how DOF difference is not visible)



For that matter I'm not sure why some landscape shooters really need to shoot smaller than f/5.6 on aps-c very much, unless they're really trying to bring close foreground in.

I actually should start tagging my photos for 'ff advantage' so I can find great examples quicker, these are just the ones I happened across


Last edited by jsherman999; 02-24-2015 at 03:10 PM.
02-24-2015, 03:13 PM   #215
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QuoteOriginally posted by jsherman999 Quote
Argh!

I hate when people misread what I say and put words in my mouth.

Shallow DOF is not the 'goal of photography.'

What I said was that the majority of the time for my shooting, the DOF either doesn't matter (subject far enough away, at hyperfocal, etc)
or it's beneficial (subject isolation). The times when I need to stop down past the point where I'm giving up DR/SNR are few and far between, for me. Even when I'm trying to isolate the subject, the environment is nicely represented without being harsh/distracting:

180mm f/2.8

180mm f.2,8, 50mm f.1.8

180mm f/2.8, 32mm f.2,8 (tamron 28-75 2.8)



Even for WA, or landscape. I'm usually shooting things where I'm taking advantage of hyperfocal or very-expanded DOF, and I usually am shooting at f/8 for those situations on both aps-c and FF. I get 'enough' DOF in both cases, in fact for that type of shooting I can't usually even see any difference in DOF, and I can take advantage of the better SNR/DR on the larger format then.

20mm f/8 (always shoot my 15ltd at f8 - this 20mm on FF gives me another stop, these are just to show how DOF difference is not visible)



I actually should start tagging my photos for 'ff advantage' so I can find great examples quicker, these are just the ones I happened across
Sorry. I'm really not trying to attack you, it just seems like a big focus of the full frame arguments come down to shallow depth of field and most of the time when I go out shooting, I am shooting stopped down. That doesn't mean I won't get benefit from full frame, but it may not be the same benefit that someone who is shooting a lot of portraits would get.

Maybe I should pay attention to the back ground more and shoot more wide open.

I shot this with the DA *55 at f4. I certainly could have shot it at f2 and the background tree would be blurred more, but I guess I wasn't particularly concerned about it.



On the other hand, by using a longer lens and having my daughter far enough in front of the trees, I guess I got some shallow depth of field here...



I don't know. When I like photos of my kids, it usually has more to do with the memories involved and not so much with the artistic nature of the photos.
02-24-2015, 03:20 PM   #216
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QuoteOriginally posted by philbaum Quote
This does not make sense to me. For example:
A. If one is using a FF Pentax lens like the FA43, the light intensity across an APS sensor versus a FF sensor is the same. The only difference on an APS camera, the light falling outside the APS circle of the sensor is wasted.
Your reasoning is correct, but note that the two images you are comparing a vastly different.

The FA43 on an APS-C camera provides a much narrower view than the FA43 on an FF camera. So the fact that both images have the same exposure (light intensity) is not really relevant as the scenes they capture are so different.

The argument I made -- that you felt didn't make sense -- applies to using a wider lens on the APS-C camera, so that you capture the same scene as with the FA43 on FF. The respective lens fit for APS-C would have to be a 29/1.3.

If you use this 29mm lens at f/2.8 on the APS-C camera and the 43mm lens at f/4 on the FF camera (the f-ratio must be higher for the 43mm so that you get the same DOF) then you capture the same total amount of light. The latter implies that the exposure (light intensity) is lower on the FF sensor, because the same amount of total light has to be spread over a larger surface, thus reducing the intensity per square millimetre.

QuoteOriginally posted by philbaum Quote
B. If you go to this DXO page: Nikon D750 versus Nikon D7100 - Side by side camera comparison - DxOMark

The sports ISO rating for the FF camera is roughly 2.25 greater than the Nikon D7100 ISO rating.
That's because DxO uses the common approach of not using equivalent f-ratios. They are just assuming the same f-ratio (say f/2.8) for all sensor sizes.

That gives all FF sensors a bit more than a stop of noise advantage. This makes sense, if one assumes that one will shoot, say f/2.8 zooms on all sensor sizes, no matter what. In that sense, the score is "practice oriented". However, strictly speaking, bigger sensors only gain a noise (sports) advantage, if you use bigger glass with them.

QuoteOriginally posted by philbaum Quote
If you are correct in your statements, why does DXOmark consider higher ISO ratings of the FF to be a favorable factor?
See above.

It is somewhat defensible to argue that an FF camera will open you the door to better "sports" performance, because it will provide access to lenses (e.g., 70-200/2.8) which have no equivalent performer in the APS-C world. The Sigma 18-35/1.8 was a game changer, since it is the first APS-C zoom that provides APS-C shooters with f/2.8-FF-equivalent performance (for a 27-53mm FF-equivalent range).

QuoteOriginally posted by philbaum Quote
I think its like Rondec stated, the noise level of the FF iso 450 is equivalent to the APS iso 200.
That statement is correct but not in conflict with anything I said. Numbers I used were "ISO 100 (APS-C) <-> ISO 225 (FF)", but the conversion (square of the crop factor) was the same.
02-24-2015, 03:33 PM - 1 Like   #217
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QuoteOriginally posted by Class A Quote
If you are saying, neither is better than the other, then I have to politely disagree.
Fair enough.

QuoteOriginally posted by Class A Quote
I'm not trying to "enforce" anything.
With all due respect, that's how your choice of language usually looks to me, like calling changing focal lengths instead of distance the 'proper' way to get the same framing (on different sensor sizes). That kind of thing, to me, looks like you're deciding how other people should compare things.

QuoteOriginally posted by Class A Quote
The wrong conclusions people arrive at ("A larger sensor has better light gathering abilities" and other such myths) tells me that their "apples to oranges" comparisons don't work.
9 times out of 10 these misconceptions come from not clearly defining the parameters that are or aren't fixed in the comparison. Like "FF has more DoF than aps-c" and "FF has less DoF than aps-c" can both be true under the right conditions and many, many disagreements could be avoided if these conditions were made explicit from the outset. I'd suggest the majority of the problem is the inherent vagueness on photography forums, lax use of terminology, and people coming at the same thing but from a different direction.
02-24-2015, 07:05 PM   #218
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QuoteOriginally posted by BrianR Quote
With all due respect, that's how your choice of language usually looks to me, like calling changing focal lengths instead of distance the 'proper' way to get the same framing (on different sensor sizes).
Changing the distance to obtain the same framing, is just not acceptable if you want to compare apples to apples.

If someone wants to compare apples (a framing with one perspective) to oranges (same framing, but using a different perspective) then they are welcome to it, but it is much harder to make meaningful DOF comparisons between such different images.

If someone wants to deviate from the simple practice of comparing images which are identical in all image-relevant parameters for the purposes of discussing differences between sensor formats, they should have a better argument than just "I can get the framing right by changing the subject distance and I don't care about the perspective change and its impact on DOF because I make the arbitrary decision to use the same lens on both formats for the same purposes". Continuing to use the same lens for the same purpose (e.g., portraits) despite a change in sensor size does not make sense from a photography aesthetics viewpoint and while it is something that someone could choose to do regardless, it just makes a comparison between sensor formats incredibly harder because one compares apples to oranges.

QuoteOriginally posted by BrianR Quote
That kind of thing, to me, looks like you're deciding how other people should compare things.
I'm not deciding what an "apples to apples" comparison is.

I admit that I'm a proponent of "apples to apples" comparisons, in particular when people performing "apples to oranges" comparisons arrive at incorrect conclusions and then teach their incorrect findings to others.

QuoteOriginally posted by BrianR Quote
9 times out of 10 these misconceptions come from not clearly defining the parameters that are or aren't fixed in the comparison. Like "FF has more DoF than aps-c" and "FF has less DoF than aps-c" can both be true under the right conditions and many, many disagreements could be avoided if these conditions were made explicit from the outset.
I'm not sure about the "9 times out of 10" but in principle I agree.

BTW, the utility of the "equivalence" approach is that it takes out all variability of the parameters by enforcing an apples to apples comparison. There is no end to the scenarios one could construct to argue the case for one particular property holding for some format in specific circumstances. A pretty fruitless endeavour, AFAIC. Hence, it is very useful to provide a level playing field and then observe which differences are present, if any. That's what falconeye did and if only more read his articles and understood them, a lot of the fruitless discussions could be avoided.

BTW, I think jsherman999's images do the talking in terms of FF advantages much better than I do. Granted, his compositions are really nice and he performs excellent post-processing, but still, I don't see images like that from APS-C cameras (including his former ones). If someone doesn't see the difference, I'm happy for them to forgo FF. I'm not happy for them, however, to tell others there is no difference or that FF is for "shallow DOF portraits only".


Last edited by Class A; 02-24-2015 at 07:11 PM.
02-24-2015, 07:19 PM   #219
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This is one of the most interesting conversations I've ever seen on here! But I don't understand a lot of it. I want to. I figure I ought to. I don't yet know how I'm ever gonna! Get out there and shoot, right?

Great photos btw!
02-24-2015, 07:28 PM - 1 Like   #220
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QuoteOriginally posted by BrianR Quote
Fair enough.



With all due respect, that's how your choice of language usually looks to me, like calling changing focal lengths instead of distance the 'proper' way to get the same framing (on different sensor sizes). That kind of thing, to me, looks like you're deciding how other people should compare things.



9 times out of 10 these misconceptions come from not clearly defining the parameters that are or aren't fixed in the comparison. Like "FF has more DoF than aps-c" and "FF has less DoF than aps-c" can both be true under the right conditions and many, many disagreements could be avoided if these conditions were made explicit from the outset. I'd suggest the majority of the problem is the inherent vagueness on photography forums, lax use of terminology, and people coming at the same thing but from a different direction.
There are exactly the same number of ƒ-stops on a lens whether you're using the lens on an APS-c camera or FF camera. One does not have more DoF flexibility than the other. The difference is the FF will give you shallower DoF wide open. I have no idea how this gets to be so complicated. The difference is one stop, when you re shooting wide open. During any other shooting situation, as in 99% of the average person's shooting, there is no difference. At 100 ISO APS_c is as good as anything out there for noise so 100-400 ISO APS-c is as good as it gets. Buy the time you've gotten over 400 ISO you've lost quite a bit of Dynamic Range even on a Full Frame, so your picture isn't what it could be.

As a photographer it's your job too know how to get the results you want with the format you're using. Setting up ridiculous situations with ridiculous parameters to show you can't get it done with one system or another? Spend your time figuring out how to get done what you need to do with what you've got, it's a lot more productive.

Last edited by normhead; 02-25-2015 at 07:21 AM.
02-24-2015, 07:36 PM - 1 Like   #221
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There is some high end discussion going on and I just wanted to commend you all for remaining civil in it.
The DoF argument on a larger format is a bone of contention for some, but there are facts that overarch the physics of it all.
The rubber meets the road when comparing what one lens can do between formats, and this can be discerned best (right now) on the existing Nikon/Canon/Sony FFs/APS-Cs.
The beauty with Pentax is, there is nothing like the FA Ltds to try on a dSLR they were designed to go on.
02-24-2015, 09:03 PM   #222
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QuoteOriginally posted by jsherman999 Quote

Here are some shots that (maybe) show what I mean when I say "DOF doesn't matter or shallow DOF is beneficial"
Great sensitive pics, Jay.

The cat acting as the family dog made me laugh!
02-24-2015, 09:12 PM   #223
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QuoteOriginally posted by Class A Quote
Perhaps that comment alone resolves the "bizarreness"?

If not, maybe this helps: Falk Lumo: LumoLabs: Camera equivalence
Or this: Equivalence
You've given a link by a blogger in the first instance, and in the second, what appears to be the Holy Scripture of Equivalence Fanatics, by, would I be wrong in saying, a fashion photographer banned twice by DPR?

Last edited by clackers; 02-26-2015 at 03:25 AM.
02-24-2015, 09:26 PM   #224
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QuoteOriginally posted by DavidSKAF3 Quote
This is one of the most interesting conversations I've ever seen on here! But I don't understand a lot of it. I want to. I figure I ought to. I don't yet know how I'm ever gonna! Get out there and shoot, right?
Top marks to you, David! :-)
02-24-2015, 10:04 PM   #225
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QuoteOriginally posted by clackers Quote
Top marks to you, David! :-)

Thanks! The other day I saw brand new K-30+18-55 WR kits on sale for just $349! Is that a great deal, or what? I already have a K-3, but I almost bought one anyway, just because! (I bought a used HD DA 55-300 WR for $269 instead)


I sold my K-5 to help pay for a K-3, but sometimes I still wish I had one of the 16mp Pentax DSLR's. I really liked the K-5, but the K-3's improved AF is noticeable. Still, it seems like the K-5's high ISO IQ is a bit cleaner. I am nobody's knowledgeable pixel-peeper, or in any way eminently qualified to back up this perception. It just seems to be so when I scroll though photos by both cameras in Lightroom. Have you ever wanted to "move up" to a K-3?

On a more relevant note, a 33mm f/0.8 lens would be pretty cool! Wouldn't it?

Thanks,


Dave the Perennial Newbie

Last edited by DavidSKAF3; 02-24-2015 at 10:20 PM.
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