Riley, you know perfectly well that FT was designed with the sensor size known. If you look at all (D)SLR lens mounts with the film/sensor known when the mount was designed, it is absolutely obvious that FT is the outlier.
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Primes Comparison Map #2 (m4/3 vs Canon vs Nikon)
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Russ Houston
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I'd prefer to see the actual lenses and not "equivalents" whatever that really means.
Thanks for the effort, though.
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Russ
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Thanks for the effort, though.
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Russ
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Even bad photography can be fun
Not only that he shot the wider apertures a second time with a 1/2 stop slower shutter speed. This allows results to be checked for internal consistency since one can answer both (for example):
a) how much underexposed is the f/0.95 image (compared to the f/4 image); and
b) how much overexposed is the f/0.95 image with the slower shutter speed (compared to the f/4 image).
boggis the cat
Veteran Member
But this is precisely the problem with the argument that "equivalent photographs" is the only meaningful equivalent. This particular equivalence is of little to no practical utility, and the relative aperture transformations used are not always made clear.
There are many equivalents that can be drawn, and the argument that lens relative aperture specifications must be modified to account for sensor size differences because DOF / light gathering / etc. is of preeminent importance is plainly stupid -- it's a narrow way of considering a system that is used by no one and it easily leads to confusion.
Clearly marking the transformations used (and/or explicitly stating what the transformation represents) is at least a step toward reducing confusion.
WRT lenses -- check where the best MTF results appear on different formats and you discover that lenses on different systems do not scale in a simple linear fashion as implied by the "equivalent photographs" argument. Stopping down on a 135 format to achieve the same DOF as a smaller sensor system may move you into a significantly worse relative aperture, so the entire premise is highly theoretical and impractical. All systems have differing strengths and weaknesses, and if you want to take the best photographs possible (from a technical POV) then you are better off ignoring theory like "equivalent photographs" and learn the system(s) you use.
Great Bustard
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This is simply not true. For example, in the center, the peak performance of the 24 / 1.4L II on FF is at f/4:
http://www.photozone.de/canon_eos_ff/514-canon24f14mk2ff?start=1
as it is for the 12 / 2 on mFT:
http://www.photozone.de/olympus--four-thirds-lens-tests/673-oly12f2?start=1
But this in no way, whatsover, puts FF at a comparative disadvantage with regards to photos at the same DOF. What it tells us is that lessening lens aberrations in the 12 / 2 still outweigh the effects of diffraction softening until a much greater DOF than the 24 / 1.4L II, where lens aberrations end their reign at a more shallow DOF.
If we need f/8 on FF for DOF reasons, then we shoot it at f/8. The fact that f/8 on FF is less sharp than f/4 on FF (due to difraction softening) is not a disadvantage for FF, and, in fact, an ideal situation (a perfect lens would be at its sharpest wide open, and less sharp as stopped down as a result of diffraction softening).
All systems suffer the same from diffraction softening at the same DOF, but not all suffer from the same lens aberrations. In this particular example, the 12 / 2 suffers greater lens aberrations at any given DOF than the 24 / 1.4L II, which is a minus for the mFT lens, not the FF lens, in this particular instance.
And who has every argued otherwise? For reference:
josephjamesphotography.com/equivalence/#purpose
So while no two photos from two different systems will ever be equal, Equivalent photos from different systems will be as similar as photos from different systems will get. Clearly, however, the point of choosing one system over another is not simply to get photos as close as possible to other systems (equivalent photos), but to get photos that look "better" (in each photographer's opinion) to what other systems can deliver (non-equivalent photos), or for the differences in operation (AF speed/accuracy, size, weight, frame rate, build, price, etc.).
We can compare systems in many different ways. The five parameters of Equivalence are simply guidelines to comparing systems on the basis of the most similar visual properties of the final photo, and are certainly not a mandate that systems must be compared in such a fashion. Therefore, it is important to specify the purpose of the comparison, and then not artificially handicap one or the other system with the conditions of the comparison. In addition, it is important to interpret the results of the comparison in the context of the circumstances where the conditions of the comparison are valid.
The point of photography is making photos. As such, one doesn't choose the particular system to get images which are equivalent to another system. A person chooses a particular system for the best balance of the factors that matter to the them, such as price, size, weight, IQ, DOF range, available lenses, and/or operation. By understanding which settings on which system create equivalent images, the difference in their capabilities is more easily understood.
boggis the cat
Veteran Member
This isn't an either / or situation.
If you start with f/2 on the mFT system and want the equivalent DOF on 135 you must stop down to f/4, in which case the 135 lens performance is a lot better.
And if you start with f/8 on the mFT system and want the equivalent DOF on 135 you must stop down to f/16, where the 135 lens performance is rolling off.
http://forums.dpreview.com/forums/read.asp?forum=1041&message=41696216
It turns out that 135 format may be better if you want shallow DOF. Amazing, eh? More interestingly, it may be worse (not equal, but worse) if you want deep DOF.
As usual, you are cherry-picking your data to contradict something that is entirely true. Try re-reading what I wrote:
Stopping down on a 135 format to achieve the same DOF as a smaller sensor system may move you into a significantly worse relative aperture, so the entire premise is highly theoretical and impractical.
Emphasis added, since you appear to be unable to think of more than two possible choices or outcomes in any situation.
agree with all this.
Framing and perspective are fundamental and it is useful to understand how to compare FL with respect to format... and this is very simple. The other stuff is more complex and it comes from experience using a system, not by bickering on the internet!
I just got one of those bargain Pan 14's and am very excited to have a 28mm eq FL lens to shoot since I haven't had this FoV in a prime since shooting film.
YAY!
mark hahn
http://emptyspacesproject.wordpress.com/
Framing and perspective are fundamental and it is useful to understand how to compare FL with respect to format... and this is very simple. The other stuff is more complex and it comes from experience using a system, not by bickering on the internet!
I just got one of those bargain Pan 14's and am very excited to have a 28mm eq FL lens to shoot since I haven't had this FoV in a prime since shooting film.
YAY!
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mark hahn
http://emptyspacesproject.wordpress.com/
That statement is not only untrue, it's just about impossible.
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Lee Jay
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Great Bustard
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Boggis, when you stop down a lens, any lens, on any system, it lessens the lens aberrations, which improves performance of the optics . If the performance of the system drops, it drops due to the effects of diffraction softening which are identical for all systems at the same DOF.
So, stopping down a FF lens to match the DOF of a 4/3 lens will never result in worse performance relative to another system. What may happen, however, is that the FF lens was not so great to begin with, long before it was ever stopped down.
Lame.
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“Imagination is more important than knowledge. For
knowledge is limited to all we now know and
understand, while imagination embraces the entire
world, and all there ever will be to know and
understand.” - Albert Einstein
bobn2
Forum Pro
What is causing the 135 lens performance to 'roll off' is diffraction blur, and the diffraction blur in the final image is exactly the same in an mFT f/8 image as it is in a 135 f/16 image.
Remember, f/8 on FT is equivalent to f/16 on 35mm FF with respect to DOF, photon noise and diffraction .
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Bob
yes, if all that matters is minimizing DoF and you only shoot your lenses wide open I guess this is slightly useful...
but then again, the 85/1.2L users who say, "I bought the lens for the aperture so I only shoot it wide open," take shitty photographs!
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mark hahn
http://emptyspacesproject.wordpress.com/
but then again, the 85/1.2L users who say, "I bought the lens for the aperture so I only shoot it wide open," take shitty photographs!
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mark hahn
http://emptyspacesproject.wordpress.com/
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