APS sensors vs. m4/3?

Amin

Hall of Famer
Jul 3, 2010
This is why I think the theory that (to give one example), a 25mm f.14 m4/3 is the same as a 50mm f2.8 full-frame in terms of angle-of-view and depth-of-field is an over-simplification. That is, the depth-of-field bit is an over-simplification, not the angle-of-view.
I've done some comparisons to illustrate it for myself, and lens "character" issues aside, I don't think it's an oversimplification. It holds up pretty well for me. Here are a couple such examples:

https://www.photographerslounge.org/f42/canon-lenses-full-frame-vs-crop-162/

https://www.photographerslounge.org...s-zd-25mm-f-2-8-vs-canon-ef-50mm-f-1-4-a-161/
 

flash

Veteran
May 6, 2011
Gordon
sorry for wasting everyone's time and bandwidth. Certainly won't be doing it again. I'm off to find a brick wall. Far more productive........

Gordon
 

Naveed Akhtar

Regular
Dec 8, 2011
London, UK
I've done some comparisons to illustrate it for myself, and lens "character" issues aside, I don't think it's an oversimplification. It holds up pretty well for me. Here are a couple such examples:

https://www.photographerslounge.org/f42/canon-lenses-full-frame-vs-crop-162/

https://www.photographerslounge.org...s-zd-25mm-f-2-8-vs-canon-ef-50mm-f-1-4-a-161/
Good work! On differnt physical focal lengths, compensated with matching Physical Apperture length and equivalent Field of View, this is exactly what was expacted!

:th_salute:

I'm off to find a brick wall. Far more productive........ Gordon
Try using dash2 between ::
 

Naveed Akhtar

Regular
Dec 8, 2011
London, UK
http://software.canon-europe.com/files/documents/EF_Lens_Work_Book_7_EN.pdf

Jump to Page 132 of Canon Lens literature, it says there:
Depth of field and perspective
The EF 85mm f/1.8 USM lens is effectively a 136mm f/1.8 lens in
terms of angle of view when attached to the EOS 30D. Looking
at these specs, it would seem possible to take a photograph with
a shallower depth of field than if the EF 135mm f/2L USM were
used with 35mm film, but this is not the case. Since the focal
length does not actually change, the depth of field in terms of
the sensors and the blurred image in the out-of-focus area
remain the same for the EF 85mm f/1.8 USM.
And if the image
is enlarged to the size of an A3 print (approx. 11 x 14 inches),
the amount of enlargement required by the EOS 30D is greater
than that for 35mm film size, because its screen size is smaller.
Nevertheless the depth of field on the print will be shallower for
the latter combination, creating greater blur in the background.
This means that if you want to achieve more blur in the
background using the EOS 30D, you will have to shoot at a
larger aperture. Furthermore, perspective is related to angle of
view, so even if the focal length is different for each particular
lens, if the resulting angle is the same due to the difference in
image size, as in the photographs shown above, the perspective
will remain unchanged, too.
 

BrianS

Legend
Jul 7, 2010
There appears to be two discussions going on concerning DOF change vs sensor size:
1) DOF with regard to Field-of-View in which different focal lengths are used with each of the sensors of different size to maintain a constant FOV for the comparison;

2) DOF with regard to focal length in which the same lens is used on cameras with different sensor sizes. The Field-of-View is not constant, and is proportional to the size of the detector used;

Scenerio 1 is of interest for choosing a camera system.

Scenerio 2 is of interest for using legacy optics on the new system.

No wonder I bought an M9.


(1936 Carl Zeiss Jena 5cm f1.5 Sonnar, coated optics, converted to Leica mount from Contax mount)

I can use my legacy 1930s lenses on it and not worry about these DOF-Perspective-FOV-SensorSize discussions.
 

flash

Veteran
May 6, 2011
Gordon
Yes Naveed. And if you read this carefully this states that shooting position remains unchanged. As I have always said, from the same shooting position a smaller sensor will have LESS DOF due to the greater magnification required to make the same print. Here, Canon states that, from the same shooting position an 85mm on a 30D will have less DOF than a 135 at the same aperture on 35mm film. Thanks for backing me up.


Gordon

p.s. Canon do make one error though (more than likely due to translation). Perspective is not altered by angle of view. Only by camera to subject distance.
 

Naveed Akhtar

Regular
Dec 8, 2011
London, UK
Thanks Brian .. for sharing the beauty, I only wish if I could have afford it, deffinately wouldn't get into that discussion of different camera formats.

however, The discussion, has always been on your point "2", which actually hijacked the origional topic APSC or 4/3 what camera you prefer! On Point "1", there was an agreement from day 1.
 

Naveed Akhtar

Regular
Dec 8, 2011
London, UK
Thanks for backing me up.
:doh:

Earlier all internet tests were wrong, now Canon is wrong, because they dont know how to translate.
Now you are speaking about two different focal lengths (there is no 135 only one focal length i.e. 85mm giving FOV equals 135, focal length is same ... same .. same .. mentioned numerous times before), while I been always talking about same lens and ONE physical focal length on two formats! Earlier you couldn't see from your own posted images if DOF is same or different and now you are pointing on the text, that actually its backing you up!

Now can you please forget about the print size for a moment and tell me if you agree on following from Canon literature or not? Because this is my only point of discussion since day 1, else show me where I said words like "print" or "display sizes":

The EF 85mm f/1.8 USM lens is effectively a 136mm f/1.8 lens in
terms of angle of view when attached to the EOS 30D. Looking
at these specs, it would seem possible to take a photograph with
a shallower depth of field than if the EF 135mm f/2L USM were
used with 35mm film, but this is not the case. Since the focal
length does not actually change, the depth of field in terms of
the sensors and the blurred image in the out-of-focus area
remain the same for the EF 85mm f/1.8 USM.
Don't read from other part of that literature, from the things I am not arguing with you here. That will be completely unnecessary!

There are number of variables that determines Dof, we are not changing any other but one thing sensor size. Because if we change anything else we are not reaching any conclusion. Also, I am not going to get into another discussion on perspective, can't correct you on each and everything. Just tell me if the quoted paragraph you are reading above, if you agree or disagree (with Canon)
 

Amin

Hall of Famer
Jul 3, 2010
sorry for wasting everyone's time and bandwidth. Certainly won't be doing it again. I'm off to find a brick wall. Far more productive........

Gordon
Gordon, thanks for providing those examples. They are helpful and potentially useful to many onlookers. You and I both know you have it right here, but it is never possible to convince everyone.

Yesterday I was at the Apple Store, and one of the workers there was trying to explain to me, in the most patronizing way possible, why the new 2560x1440 27" display actually gives you more screen real estate than the old 2560x1600 30" display. It was because the pixel pitch was smaller, she said, that I could view more of a spreadsheet on the smaller display. I spent about 5 minutes trying to explain to her where she had it wrong, and then I had to walk away.
 

pdh

Legend
Jan 2, 2011
luckypenguin said:
25mm f.14 m4/3
I hadn't seen that lens yet, Nic, but it's a fantastic reason to pick m4/3 over APS ... what's the DoF like wide open?
 

BrianS

Legend
Jul 7, 2010
I remember Kingslake writing about "real" and "apparent" perspective.

Kind of like average landspeed of African or European Swallow.

Again- a word that can have two different and accepted definitions, with both being correct but arguing past each other in a conversation if not differentiated.
 

bartjeej

Hall of Famer
Nov 12, 2010
bart
One of my absolute conditions with any camera is that it's jacket-pocketable, so for me m4/3 offers a clear advantage in terms of lens size, although Samsung is doing a very nice job creating pancake lenses for their APSC cameras. One thing I prefer about APSC is the aspect ratio; 3/2 suits me better in most cases than 4/3. I really like Panasonic's variable aspect ratio sensors, they're perfect for me :)
 

Luckypenguin

Hall of Famer
Dec 24, 2010
Brisbane, Australia
Nic
I've done some comparisons to illustrate it for myself, and lens "character" issues aside, I don't think it's an oversimplification. It holds up pretty well for me. Here are a couple such examples:

https://www.photographerslounge.org/f42/canon-lenses-full-frame-vs-crop-162/

https://www.photographerslounge.org...s-zd-25mm-f-2-8-vs-canon-ef-50mm-f-1-4-a-161/
Note that I described it as an over-simplification, not as being incorrect. The theory is there and the numbers coming out of the dof calculators back it up, but I question how directly applicable the theory is in the real world since it relies on some generalisations and because lens character is a real phenomenon...

To make some generalisations of my own (re the capability to achieve a shallow depth-of-field),


In favour of smaller formats like 4/3 and m4/3:

- Lenses all display different out-of-focus characteristics and can give the impression of more or less dof for the same given aperture. This could actually go either way for each format (less apparent dof, more apparent dof of a given lens).

- My experience is that most m4/3 and 4/3 lenses perform hit their optimum range at larger apertures compared to larger formats which makes it more likely for me to shoot them at those apertures. In comparison I've tried various SLR lenses that seemed fairly disasterous at larger apertures and I wouldn't really consider going there.

- Shooting a stopped-down lens on a larger-format camera to reduce the dof can (but not always) give bad bokeh highlights depending on the configuration of the aperture blades. This is another lens character issue.

- Less dof is not always a good thing


Against the 4/3 and m4/3 format:

- Base ISO of 200 and minimum shutter speeds of 1/4000 doesn't have the exposure latitude of an ISO 100, 1/8000sec DSLR to open up the lens in bright light without the use of something like an ND filter.

- Lens availability (specifically zooms). An APS camera with a 17-55mm f2.8 is going to kill an m4/3 camera with a 14-4Xmm f3.5-5.6 for achieving a shallow depth of field since there are no native fast m4/3 zooms. A 4/3 camera with a 14-5Xmm f2.8-3.5 will manage to almost hold it's own.


All this and probably more is why I think the dof equivalence theory is not as simple as it sounds. Like a lot of theories it relies on controlled variables to be completely accurate. This is why I was never much good at university; too much time spent pondering real world application, not enough time spent accepting what I was being taught :S

Even though I used the example earlier of 25mm m4/3 and 50mm full-frame, I also think the m4/3 vs full-frame comparison is quite a stretch based on price alone, and that the true comparison is between m/3 and APS-C format cameras just as the thread title was asking.
 

BrianS

Legend
Jul 7, 2010
Two years ago the Olympus EVF was the best available for mirrorless cameras and is the reason that I bought two of them. One for work, with the IR absorbing glass replaced by a clear cover and a "regular" one for personal use. The latter gets used with a lot of legacy glass. Having a mode in which mimics an SLR, with a focus aid in the center and full-frame viewing to allow framing would be nice. I would have liked Olympus to have added a zoom-spot in place of shifting back and forth between magnified and 1x mode. I've read that the NEX7 does this, and I will look at it. I would be able to focus and frame faster with such a feature. I have a lot of lenses, some which do not have a Digital heir to the line. I have the Leica lenses covered. I've never bothered to upgrade from the D1x, and the NEX7 is more tempting than a D-whatever. The 1.3x crop factor of the M8 is close to the NEX, something that I am used to. The 2x crop of the EP2 and u43 in general turns all of my favorite lenses into a 100mm equivalent.

The Jupiter-3 5cm F1.5 used wide-open on the EP2 really does remind me of the Nikkor 10.5cm F2.5 wide-open on the SP and M9. I need to use the Contax version more.

 

flash

Veteran
May 6, 2011
Gordon
Yesterday I was at the Apple Store, and one of the workers there was trying to explain to me, in the most patronizing way possible, why the new 2560x1440 27" display actually gives you more screen real estate than the old 2560x1600 30" display. It was because the pixel pitch was smaller, she said, that I could view more of a spreadsheet on the smaller display. I spent about 5 minutes trying to explain to her where she had it wrong, and then I had to walk away.
Haha. That's classic.

Gordon
 

Naveed Akhtar

Regular
Dec 8, 2011
London, UK
Note that I described it as an over-simplification, not as being incorrect.
.
.
Even though I used the example earlier of 25mm m4/3 and 50mm full-frame, I also think the m4/3 vs full-frame comparison is quite a stretch based on price alone, and that the true comparison is between m/3 and APS-C format cameras just as the thread title was asking.
:bravo-009:

A very practical and sensible response, the trouble with more technical less practical, controlled variable, camera addicts like myself, we often ignore these points and trapped into discussion which normally is less useful and more confusing for most of us! :daz:
 

Naveed Akhtar

Regular
Dec 8, 2011
London, UK
I also think the m4/3 vs full-frame comparison is quite a stretch based on price alone, and that the true comparison is between m/3 and APS-C format cameras just as the thread title was asking.
I agree again, the reasons in controlled parameter testing, I normally reffer to full-frame with any other smaller format are:
a) the difference is normally huge and it helps clear myths
b) full-frame uses more standard terms and real measurements like 35mm sensor (length) 50mm focal length (is physically 50mm) and generally considered as more common format since the film era.
 

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