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01-16-2012, 06:36 PM   #2116
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QuoteOriginally posted by falconeye Quote
To address your particular comment: An FF 40mm/2.8 and an APSC 27mm/1.9 are equivalent lenses, giving same DoF and same low light performance. .

They are not equivalent lenses. A 40/2.8 and a 27/2.8 are equivalent lenses. The differences in quality is due to the different size of the formats. Two lenses for two formats have the same ligh gathering abilities when shot at the exact same aperture value and ISO. This yields the same exposure proving the equivalence. The bigger formats will yield better image quality; thats why people buy larger formats in the first place. Different formats do not give same DOF at the same magnification at the same aperture value. Thats what define formats. Formats aren't equal. Thats why trying to equalize them is meaningless. Trying to make formats behave equally is red herring cause you can construct arguments, ususally with no real relevance for real life photography, to suit any format over another just by picking your arguments.
Nobody buy an APS camera in order for it to be equal to an FF camera or even the 645D or vice versa.

01-16-2012, 06:38 PM   #2117
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I think the only benefits of full frame are increased control over depth of field and the fact that old lenses can be used as they were intended (for instance all those inexpensive 50mm lenses are not telephotos). The difference in IQ between full frame and aps-c is negligible. Sure, full frame sensors will always be a step ahead, but if you wait a year or two the aps-c sensor will catch up. Even smaller sensor cameras can have very good image quality. My brother is getting beautiful images out of his Nikon p7000, which does not even have a aps-c sensor (This is actually a great camera for the price, only $250 right now).

I am ok with Pentax introducing a full frame camera, but would much rather have them put their resources into something innovative that has the potential to capture a portion of the mirrorless market. If this happens to be full frame, it is ok. However, I do not believe a mirrorless full frame camera is cost effective unless you optimize the sensor to take leica lenses.
01-16-2012, 06:44 PM   #2118
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QuoteOriginally posted by kswier Quote
I think the only benefits of full frame are increased control over depth of field .
I have to protest again
There are no more control over DOF with FF. APS and FF have exactly the same control over DOF as long as lenses with comparable aperture range is used, but DOF will be different at the same aperture value and the same magnification. You need to stop down more on the larger format to get the same DOF - genereally not seen as a plus (thats why large format have tilt/shift). APS have in fact a more useful DOF range as hardly anyone will use shallower DOF than what is possible at F:1.4 and F 1.2 on APS, (a DOF so shallow that is hardly usable), but plenty of situations where F:22 on FF is not adequate (eg in landscape photography). But in real life, the DOF differences between APS and FF is negligible.

Last edited by Pål Jensen; 01-16-2012 at 06:53 PM.
01-16-2012, 08:47 PM   #2119
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QuoteOriginally posted by Pål Jensen Quote
They are not equivalent lenses. A 40/2.8 and a 27/2.8 are equivalent lenses. The differences in quality is due to the different size of the formats. Two lenses for two formats have the same ligh gathering abilities when shot at the exact same aperture value and ISO. This yields the same exposure proving the equivalence. The bigger formats will yield better image quality; thats why people buy larger formats in the first place. Different formats do not give same DOF at the same magnification at the same aperture value. Thats what define formats. Formats aren't equal. Thats why trying to equalize them is meaningless. Trying to make formats behave equally is red herring cause you can construct arguments, ususally with no real relevance for real life photography, to suit any format over another just by picking your arguments.
Nobody buy an APS camera in order for it to be equal to an FF camera or even the 645D or vice versa.
Falk has it right, for the definition of equal that he uses. You seem to disagree on what is equal. I'll side with Falk. He describes what is required to get an identical image. That seems like a reasonable definition of equal to me. You describe what is needed to get the same exposure parameters but different images. That seems less equal.

Your definition gives the same amount of light per sensor area, Falk gives the same amount per whole sensor. So you give a noise advantage to the bigger format, Falk doesn't. Again, he seems to get it more equivalent.

Note that he's not anywhere suggesting that you need the equivalents, he's just describing what they are.


Last edited by drougge; 01-16-2012 at 08:48 PM. Reason: Messed up the logic
01-16-2012, 09:45 PM   #2120
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QuoteOriginally posted by Pål Jensen Quote
I have to protest again
And I have to protest Pål's protestation once again.

QuoteQuote:
There are no more control over DOF with FF.
With the lenses we have available to buy, there most certainly is more DOF control available with FF. If we were able to design magical lenses for aps-c, or possible-but-exotic lenses with somehow-affordable prices, then yes, there would be no greater control with FF. But until they make a tiny, good, inexpensive 13mm f/1.8, 16mm f/1.8, 24mm f/1.2, 35mm f/1.2, 120mm f/1.8, etc, well have to depend to FF for those FOV/DOF combos.

Past 200mm, there are affordable options for both formats, and the size/price issue actually starts to favor aps-c.

QuoteQuote:
You need to stop down more on the larger format to get the same DOF - genereally not seen as a plus (thats why large format have tilt/shift).
If you need to stop down to gain more DOF with FF, you can. With aps-c, you don't always have the ability to open the lens up wider to get less DOF.

QuoteQuote:
APS have in fact a more useful DOF range as hardly anyone will use shallower DOF than what is possible at F:1.4 and F 1.2 on APS,
Many people do, especially when the subject is more than a few feet away and the DOF has expanded to hold the subject nicely, but not so much that subject isolation is compromised.

Even more frequently, they enjoy shooting f/2.8 zooms and getting f/1.8 DOF capability as an option, or stopping any of their lenses down to f/4 to get sweet-spot blistering sharpness on the focal plane while maintaining a pleasing f/2.5 DOF and subject isolation, for example. It shouldn't require too much imagination to see how these options could be useful for a photographer.



.
01-16-2012, 10:04 PM   #2121
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QuoteOriginally posted by Pål Jensen Quote
They are not equivalent lenses. A 40/2.8 and a 27/2.8 are equivalent lenses.
No, they don't give equivalent images with regard to FOV/DOF. You'd need about a 27 f/1.8 on aps-c to match a 40 f/2.8 on FF.
If you don't care about the DOF difference, then yes they are equivalent with regard to FOV and exposure... but then that's not really equivalent if DOF is different, is it?

QuoteQuote:
Formats aren't equal. Thats why trying to equalize them is meaningless. Trying to make formats behave equally is red herring cause you can construct arguments, ususally with no real relevance for real life photography, to suit any format over another just by picking your arguments.
Equivalence is not used try to make the formats equal somehow, it's simply used to describe the differences in the formats by prescribing what focal lengths and apertures and ISO settings would be needed to create equivalent images on each format.

QuoteQuote:
Nobody buy an APS camera in order for it to be equal to an FF camera or even the 645D or vice versa.
???


.
01-16-2012, 10:22 PM   #2122
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I think you guys are demonstrating very well why Pentax would hesitate to go with FF.
01-16-2012, 11:16 PM   #2123
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QuoteOriginally posted by Pål Jensen Quote
Hardly any picture ever published rely on on DOF too shallow not to be possible also with APS.
More DOF at a certain magnification at a certain aperture is more useful in 99% of real life cases...
You can also make DOF appear even more dramatic by using a more telephoto focal length. The reason being that because lets say a portrait picture of an entire person with a mountain over their shoulder might be the same level of out of focus-ness at 40mm, but because at say, 85mm, it's a very close mugshot of the subject, the mountain becomes more of a part of the image and it's defocused nature becomes much more apparent.

What I want to know is when people started comparing each trait more so than actually using them to create compelling images.

If you want paper thin DOF, you need a faster lens, not a larger sensor. One is far easier and far more dramatic than the other.

01-16-2012, 11:24 PM   #2124
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I think the most important matter between APS-C and FF is the lenses capability to produce lines/millimeter.
All lenses have their max capability to produce lines/millimeter, and if you have bigger lens and bigger sensor, you for sure get sharper images.
01-16-2012, 11:31 PM   #2125
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QuoteOriginally posted by Kryscendo Quote
If you want paper thin DOF, you need a faster lens, not a larger sensor. One is far easier and far more dramatic than the other.
Actually faster lens AND large sensor will both help to get thin DOF.
01-17-2012, 12:29 AM   #2126
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QuoteOriginally posted by markku55 Quote
What do you think about this professionals opinnion:
DSLRs are a dying breed – 3rd Gen Cameras are the Future

Could pentax be one of the first of making 3rd generation cameras?
If I understood right, the 3rd generation could be called "fully electronic system camera".
I have some ideas/suggestions/opinnions about future:
1. The body do not have any moving parts when taking the picture.
2. Even the lens should not have any moving part when taking the picture.
3. Lenses will have their own software which informes the body what should be modified to make the picture right, means that the only job for the lens is to make sharp picture, the software will take care of all faults coming from more simple and light weight lens construction.
4. This new camera could use some kind of new generation sensor, which can have high ISO with high quality picture as a result.
5. FF size may be not needed anymore, even the system size can be smaller than no FF DSLR:s today.
6. Believe me, there will for sure be third generation cameras which have no limitation coming from film era.
I'll skip 3rd Gen Cameras and wait for 4th Gen Cameras which will finally avoid the use of Photographer
01-17-2012, 12:59 AM   #2127
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QuoteOriginally posted by markku55 Quote
Actually faster lens AND large sensor will both help to get thin DOF.
Right.

My point is, which one does more of the work? If you had to choose one or the other.

And again, a telephoto/fast lens would give you the appearance of even shallower depth of field because, all together now children... telephoto lenses compress space.

Very good class.
01-17-2012, 01:11 AM   #2128
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QuoteOriginally posted by Kryscendo Quote
Right.

My point is, which one does more of the work? If you had to choose one or the other.

And again, a telephoto/fast lens would give you the appearance of even shallower depth of field because, all together now children... telephoto lenses compress space.

Very good class.
With the FF you can use 1,5 times longer lens to get same angle of view compared to APS-C lens. Means with the same angle of view and F-stop the FF do have shorter DOF because of longer focal length.
01-17-2012, 01:34 AM   #2129
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When making a picture of the same object a difference of the focal length / angle of view changes nothing relevant about the DOF. They are the same.
It does change the maximum blur of the background though quite a bit. People tend to "forget" that with a tele-lens you do want to keep a bigger distance to the target.
On the other hand the change in sensor size affects the DOF, but not really the maximum blur of the background.
01-17-2012, 01:43 AM   #2130
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I do not really understand what you mean, but if I take a picture with same distance to the object, FF 50mm F2,8 and APS-C 33mm F2,8 (both have the same angle of view) the DOF is for sure shorter with the FF - or have I understood complete wrong
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