Full frame cameras

[joebranko]

As only Olympus and Panasonic make mFT cameras, you are going to run into the same lens compatibility issue as with a FF camera.

Thanks Manfred. Yes, but my plan is only to buy the body and kit lens and take as a back-up to my Canon T2i.

[george013]

I answered most of this in post 49.

I didn't mention background blur. For a given framing and DOF, background blur is a function only of angle of view, so my post answers that as well.

Detail, resolution, and diffraction all depend on pixel pitch and simply can't be answered by reference only to focal length and sensor size.

Maybe you didn't understand my question. It has a double question mark.
The quotes are from a link with a more "scientific approach" Ted gave us. Two equal images made with 2 different sensor sizes can have an equal aov AND perspective. But can they have also an equal dof AND diffraction broadening AND shutter speed/exposure? It's an "AND relation".

George

[billtils]

Thanks Manfred. Yes, but my plan is only to buy the body and kit lens and take as a back-up to my Canon T2i.

Joe, this is secondhand but is from one of my photo-buddies (from a different site) who was a long-time Canon 5DIII user but gave it up about 3 months ago and moved to an Olympus. He sent me some side-by-side comparisons and it was hard to tell the difference. Mind you, he bought the top of the line E-M1 Mark II which is a bit more than a "back-up" level rig.

EDIT: He changed because he was at a point where the weight of the Canon rig was too much for him to manage.

[DanK]

Maybe you didn't understand my question. It has a double question mark.
The quotes are from a link with a more "scientific approach" Ted gave us. Two equal images made with 2 different sensor sizes can have an equal aov AND perspective. But can they have also an equal dof AND diffraction broadening AND shutter speed/exposure? It's an "AND relation".

George

I understood your question.

1. AOV: answered above. Yes
2. Perspective: answered above. Yes
3. Diffraction: answered above. This is a function of pixel size, not sensor size, so it can't be answered without additional information.
4. DOF: answered above. yes, if you open the aperture wider on the smaller-sensor camera to compensate (assuming the aperture goes wide enough to allow one to do this).
5. Shutter speed/exposure: of course. Exposure is a function of the intensity of the light, so it is unaffected by sensor size. Imagine that you metered off a uniform gray surface and got an ideal exposure. Now crop the image. Would it be darker or lighter? No.

Of course, you can have an "AND relationship" among these. Leaving out (3), which can't be answered without more information, can you have 1 AND 2 AND 4 AND 5? Yes.

If anyone has reason to think I got any of these 5 wrong, they can chime in.,

[Manfred M]

He sent me some side-by-side comparisons and it was hard to tell the difference.

When I look at my mFT camera versus FF camera results on the computer and shoot at an ISO setting of less than 400, I can say the same thing. The moment I use anything higher, the results change and digital noise is noticeable. When it comes to prints, the difference is obvious even in smaller sizes.

The deal-breaker for me is the equivalence issue. For the same "view", I need a lens that is 2 stops faster than my FF to get the shallow DoF I use in a lot of my shots. In shots where I use a f/2.8 lens on FF, I would have to buy a f/1.4 lens in mFT.

The other issue with an mFT camera is that in being physically smaller, there is less real estate on the camera body for controls and buttons. The ones that are there are smaller and harder to "landmark". This means a lot of functionality I can access directly on my FF camera body, without taking my eye away from the viewfinder are menu driver in my mFT camera.

EDIT: He changed because he was at a point where the weight of the Canon rig was too much for him to manage.

If size and weight are the primary considerations, then I totally agree. This was my motivation when I bought my mFT camera; two months of backpacking in South-Asia with a 50 liter backpack meant I had no space for my FF gear. My mFT body and lens weight about 500 g / 1 lb less than my APS-C body. When trekking at altitude, I was very happy about missing that weight.

[DanK]

I was going to write a post similar to Manfred's but decided not to only because my MFT is not a particularly expensive one, so comparing it to a 5D III introduces a confound with quality. however, I agree with all of Manfred's points. When I don't need anything more than 2x base ISO, don't need shallow DOF, and will only display at moderate resolutions, the MFT can be fine, and mine is so small (Lumix LX-100) that I can throw it in a fanny pack or a jacket pocket. Under some other conditions, however, it just isn't in the same league as the 5D III.

One reason I have the LX-100 is the issue of limited real estate and controls. The Lumix has big, dedicated external dials for shutter speed, aperture, and EC, so apart from changing ISO, I can go all day without having to work through menus. That's not true of many of the other very small MFT and 1" cameras.

[William W]

. . . Of course, you can have an "AND relationship" among these. Leaving out (3), which can't be answered without more information,
can you have 1 AND 2 AND 4 AND 5? Yes.
. . .

I love that branch of mathematics! Made my day.

[pnodrog]

Maybe you didn't understand my question. It has a double question mark.
The quotes are from a link with a more "scientific approach" Ted gave us. Two equal images made with 2 different sensor sizes can have an equal aov AND perspective. But can they have also an equal dof AND diffraction broadening AND shutter speed/exposure? It's an "AND relation".

George

George, you are totally correct in being sceptical about the concept of equivalence. It is a flawed concept initiated by some camera reviewers in an attempt to put different format cameras on an equal footing. They are not. Those who are not sufficiently knowledgeable to appreciate the concept are not helped by it's use. Those who understand what equivalence really means also understand the implications of using different formats without the need of using equivalence comparisons.

To ignore the effect on shutter speed (or ISO) when using an equivalent aperture to achieve a matching DOF prevents the equivalence concept from being of any practical relavence other than possibly in reference to studio, landscape or similar photography.

I will now take cover...☺

[george013]

George, you are totally correct in being sceptical about the concept of equivalence. It is a flawed concept initiated by some camera reviewers in an attempt to put different format cameras on an equal footing. They are not. Those who are not sufficiently knowledgeable to appreciate the concept are not helped by it's use. Those who understand what equivalence really means also understand the implications of using different formats without the need of using equivalence comparisons.

To ignore the effect on shutter speed (or ISO) when using an equivalent apature to achieve a matching DOF prevents the equivalence concept from being of any practial relavence other than possably in reference to studio, landscape photography or similar.

I will now take cover...☺

Thanks for the post. At least somebody does understand what I mean.

George

[george013]

I understood your question.

1. AOV: answered above. Yes
2. Perspective: answered above. Yes
3. Diffraction: answered above. This is a function of pixel size, not sensor size, so it can't be answered without additional information.
4. DOF: answered above. yes, if you open the aperture wider on the smaller-sensor camera to compensate (assuming the aperture goes wide enough to allow one to do this).
5. Shutter speed/exposure: of course. Exposure is a function of the intensity of the light, so it is unaffected by sensor size. Imagine that you metered off a uniform gray surface and got an ideal exposure. Now crop the image. Would it be darker or lighter? No.

Of course, you can have an "AND relationship" among these. Leaving out (3), which can't be answered without more information, can you have 1 AND 2 AND 4 AND 5? Yes.

If anyone has reason to think I got any of these 5 wrong, they can chime in.,

3. Diffraction is a property of the lens, solely. It's based on the relation aperture diameter and image distance. What you refer to is when it's becoming visible. There're different approaches to that based on pixel size, x-time pixel size or coc.

4. Dof is based on the coc, which is based on the enlarging of the sensor frame to a certain size, about A4. The coc of a smaller sensor is smaller. If you want to correct that, you must change the aperture, another f-number BUT....

5. You can't change the f-number without changing the shutter speed/exposure.

So there's no AND AND AND AND relation.

George

[Manfred M]

Paul (and George) - let me offer an alternative position and one that I suspect is held by most photographers.

First of all, from a theoretical standpoint, I agree with what you have written. From a practical standpoint, not as much. Here there is another "test". If a knowledgeable observer cannot tell the difference between two images under normal viewing conditions, then I would suggest we have equivalence. In practice, I have found that only one or two parameters make a meaningful difference in output.

1. Perspective and field of view will be picked up by most observers.

2. Depth of field and the related effects of foreground and background focus will also be commonly picked up, if these are significant elements in the image.

3. ISO, shutter speed, diffraction, etc may be picked up under certain circumstances but in general will not be noticed.

[Manfred M]

Diffraction is a property of the lens, solely. It's based on the relation aperture diameter and image distance. What you refer to is when it's becoming visible. There're different approaches to that based on pixel size, x-time pixel size or coc.

Diffraction is caused by the aperture setting used in a lens, but the effect of diffraction blurring is dependent on the camera sensor resolution. If the sensor resolution is high enough this softening can be noticeable, but if it is not, the low resolution will prevent the viewer from detecting diffraction softening.

You can't change the f-number without changing the shutter speed/exposure.

That is definitely not true. When shooting existing light, I can use a neutral density filter to change exposure (in one direction only). When using flash, I can change the flash power. In both cases I can keep exactly the same shutter speed and ISO settings when I change shooting aperture. I use both these techniques in my work.

[DanK]

George: I interpreted your question as being "an equivalent image," not "an equivalent image with the same settings." The answer, if the latter was your question, is an obvious "no".

The answer to the first is: yes, you can often get an equivalent image--leaving aside diffraction effects (which do depend on pixel pitch)--as long as you have the flexibility to adjust aperture to create comparable DOF.

Paul, you wrote:

To ignore the effect on shutter speed (or ISO) when using an equivalent aperture to achieve a matching DOF prevents the equivalence concept from being of any practical relavence other than possibly in reference to studio, landscape or similar photography.

I think you meant "a non-equivalent aperture to obtain a matching DOF". Regardless, I think your statement is too strong. In much of my photography, a change of one stop in shutter speed has no appreciable impact, and in some of it, it has no impact whatever. The concept of "equivalence" has a great deal of practical importance for me, when I switch between the two formats.

[george013]

Manfred.

Difraction. You're repeating what I wrote with other words.

The link and qoute is about equivalent camera's. I don't think using external tools as filters or flash is accepted. Beside that something is written:

You can't change the f-number without changing the shutter speed/exposure.

Exposure is a combination of shutter speed and diafragma.

Dan,
Again, see post 48.


Peter or pschlutte,

I always find it mildly amusing that many other forums are full of discussions over FF versus aps-c, but strangely very little is posted about FF or aps-c versus Medium Format (or any other format for that matter)

Medium Format is not much else as another sensor size.



I don't give a damn about equivalent camera's. I'm just responding to a "more scientific" link.
A FF gives easier access to a bigger aov. And has some smaller dof. If you don't use that, there's no reason to switch from crop to FF.
That was enough for me.

George

[xpatUSA]

George, you are totally correct in being sceptical about the concept of equivalence. It is a flawed concept initiated by some camera reviewers in an attempt to put different format cameras on an equal footing. They are not. Those who are not sufficiently knowledgeable to appreciate the concept are not helped by it's use. Those who understand what equivalence really means also understand the implications of using different formats without the need of using equivalence comparisons.

To ignore the effect on shutter speed (or ISO) when using an equivalent aperture to achieve a matching DOF prevents the equivalence concept from being of any practical relavence other than possibly in reference to studio, landscape or similar photography.

I will now take cover...☺

No need to take cover, Paul. +1 from me.

OT, but related nevertheless:

In another Forum, far, far away, it is popular to compare images from Foveon X3 and Bayer CFA sensors, usually with wildly different image sizes and lots of re-sampling and post-processing, with no mention of equivalence at all. Makes me quite grumpy upon occasion ...

[pschlute]

Peter or pschlutte,

Medium Format is not much else as another sensor size.

George

My point was that "equivalence" has only become a widespread topic for discussion with the advent of the digital aps-c sized sensor. The introduction of the FF digital sensor gave it new legs. When I was happily snapping away with a 35mm film camera and 50mm lens no-one ever tapped me on the shoulder (no internet forums then) and told me that my 50mm lens was a wide-angle of "x" mm equivalence in MF terms. Nor did i hear anything of equivalence when the aps-c film cameras were first launched.

To me , equivalence is a proposition created by the digital camera industry in the early days to try and assist film camera users to switch to digital. It is just a source of confusion.

[Manfred M]

My point was that "equivalence" has only become a widespread topic for discussion with the advent of the digital aps-c sized sensor. The introduction of the FF digital sensor gave it new legs. When I was happily snapping away with a 35mm film camera and 50mm lens no-one ever tapped me on the shoulder (no internet forums then) and told me that my 50mm lens was a wide-angle of "x" mm equivalence in MF terms. Nor did i hear anything of equivalence when the aps-c film cameras were first launched.

To me , equivalence is a proposition created by the digital camera industry in the early days to try and assist film camera users to switch to digital. It is just a source of confusion.

I'm going to have to disagree with you Peter. I remember having the exact same conversations over 40 years ago when looking at film cameras; from 35mm to medium format right through to cameras that shot various sizes of sheet film.

[DanK]

My point was that "equivalence" has only become a widespread topic for discussion with the advent of the digital aps-c sized sensor. The introduction of the FF digital sensor gave it new legs. When I was happily snapping away with a 35mm film camera and 50mm lens no-one ever tapped me on the shoulder (no internet forums then) and told me that my 50mm lens was a wide-angle of "x" mm equivalence in MF terms. Nor did i hear anything of equivalence when the aps-c film cameras were first launched.

To me , equivalence is a proposition created by the digital camera industry in the early days to try and assist film camera users to switch to digital. It is just a source of confusion.

Equivalence has been an issue for a long time. What's changed, IMHO, is that more people are choosing among formats and even using more than one. When I started out, I had friends who used TLRs (620 format, if I recall), and far more friends who used 35 mm SLRs (as I did), but most amateurs shot one format most of the time, if not all, and so there really wasn't much reason to think about equivalence. Moreover, people who wanted interchangeable lenses typically shot 35 mm, making equivalence even less of an issue.

The other factor, I think, is that until recently, FF format DSLRs were prohibitively expensive for many people, and for people who were used to shooting in the 35mm format, the notion of equivalence was an important part of the transition. I grew up thinking of 35mm as a moderate wide-angle lens; for years after I switched to digital, on most DSLRs, including the ones I could afford, 35mm was closer to a normal lens in terms of AOV. Perhaps you didn't, but I found that knowing equivalence of AOV was very helpful.

[William W]

I'm going to have to disagree with you Peter. I remember having the exact same conversations over 40 years ago when looking at film cameras; from 35mm to medium format right through to cameras that shot various sizes of sheet film.

Me too.

Though it wasn't formed in a written paper such as those cited in this conversation; and it didn't have a name "Equivalence" - it was most definitely discussed: that is, the relationships of format sizes; lenses and apertures were discussed in respect of attaining "like photos" (i.e photos that looked "the same").

During the late 1970 and mostly all of the 80 most established W&P Studios in my collegiate were running 645 or 6x6 for the basic coverage and additionally often a 6x7 or 6x9 or even a 5x4 for 'Formal Bridal Portraiture'.

Although 135 Format was being used by quite a few Wedding Photographers, and increasingly so, established Studios were quite stalwart in not converting to the 'miniature format' (technical classification) of 135.

On this particular point, I remember a very heated meeting of the Institute, to which I then belonged, concerning the 'professional' uses of 135 format.

It was at that meeting I first heard of the useful topic [now termed] 'Equivalence" - it was contained in a gush of enthusiasm, not so eloquently delivery from a Photographer who really knew his stuff - he was my first 'boss' and I had always admired is gifted intellect and talent, probably more noticeable because it often gushed without eloquence and from a guy who had very little formal schooling.

Paul stole the show with his instruction of what could be achieved using 135 Format, and the absolute impossibility of achieving the same 'look' using Medium Format or larger cameras.

Obviously much of the emphasis was about using very fast Prime Lenses (135 Format) and then noting the impossibilities of doing the same or even similar Shallow DoF with an F/2.8 Prime on a MF camera: that conversation had been had several times - and still exists now: but I do recall Paul taking the idea of "the achievability of 'same results' between different formats" much further than just wanting to get a very Shallow DoF.

Looking back now, that evening was certainly a discussion about "Equivalence".

WW

[pschlute]

I guess I was wrong on the origins of "equivalence" and I apologise. I imagine it was because I never looked seriously at MF cameras that it just never came up for me.

Dan, you are correct in that when i moved into the digital world for the first time I had to make an adjustment in how I regarded FL.

I think the point I am trying (and failing !) to make is that there is a lot of misunderstanding among newcomers to photography about equivalence. I see many posts on other forums where folk think that an aps-c 100mm lens is a different focal length compared to a FF 100mm lens. Or they think that a aps-c sensor and lens will give greater "reach" than a FF camera and the same FL, without understanding the significance of pixel density and the "enlargement" of the smaller sensor image.