A few words on Equivalence and comparing systems

Started Apr 2, 2013 | Discussions
OP Great Bustard Forum Pro • Posts: 41,911
Crop factors and Equivalents
1

69chevy wrote:

So...

My camera phone has a crop factor of 7.64, the lens is 3.85mm and the aperture is f2.4.

The FF equivalent is 30mm f2.4?

No -- the FF equivalent is 29mm f/18 (3.85mm x 7.64 = 29mm, f/2.4 x 7.64 = f/18).

Why bother comparing different formats?

Why compare different anything?  That said, there's no point in bringing up Equivalence if you are not comparing different formats.

If you use both, you should still know the FOV of all of your lenses from experience.

One would hope that you know more than just the FOV.

Apples and Oranges if you ask me (which you didn't).

More like V8s and in-line 4s, actually.

richarddd
richarddd Veteran Member • Posts: 3,101
Re: Perhaps the real question should be.....
2

jalywol wrote:

I frequently feel that this particular argument is perpetuated by non-M43 users who are trying to prove how INCOMPETENT M43 is to make themselves feel better about their own DSLR choices.  I often wonder what cameras the loudest equivalence complainers have....are they really FF users, or are they APS-C users trying to justify the small gains in DOF of their APS-C models over M43?  Perhaps the answer to these arguments should simply be: Why not try out the M43 cameras and lenses and see if they work for you?  No point in getting into this fray again and again.....

I suppose we all have our own frames of reference.

I see a lot of posts to the effect that m43 is better than FF because, for example, a m43 35-100/2.8 is much smaller, lighter and less expensive than a FF 70-200/2.8 lens.

The OP in this thread certainly doesn't fit your description of equivalence posters in the quoted paragraph

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forpetessake
forpetessake Veteran Member • Posts: 4,892
why did you show up then?

Mjankor wrote:

And now the idiots show up...

richarddd
richarddd Veteran Member • Posts: 3,101
Re: The role of ISO
1

Great Bustard wrote:

Dr_Jon wrote:

The only issue I have with all the equivalence talk, other than that it is the the topic that "keeps on giving" is that when I put a 70-200 f.28 lens on my FF camera my first thought isn't "Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops".

Although it is fair to say GH3 ISO is really equivalent to a bigger number than FF ISO in some ways (i.e. noise) and just reflects the smaller sensor needs more "gain" to get the exposure and so the ISO is just what makes the maths work. (People do seem to see ISO as some thing that is equivalent between systems, rather than being implemented as a fudge-factor to make exposure maths work).

First of all, please take a read of gollywop's outstanding post on exposure to see what ISO is all about:

http://www.dpreview.com/forums/post/51136862

Secondly, if "when I put a 70-200 f.28 lens on my FF camera my first thought isn't 'Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops'." then you are thinking wrong.

Instead, you should be thinking that FF will use two stops higher ISO than mFT for the same DOF and shutter speed as mFT.  But often, when there is ample light, FF will be able to shoot whatever DOF they want and use a lower shutter speed than mFT.

For example, while the FF photographer might shoot 200mm f/5.6 1/400 ISO 1600 as opposed to 100mm f/2.8 1/400 ISO 400 on mFT, they might also shoot at 200mm f/5.6 1/400 ISO 100 as opposed to 100mm f/2.8 1/1600 ISO 100 on mFT, light permitting.

In any camera, you should be setting exposure to maximize light on the sensor consistent with desired DOF and motion blur, but without clipping highlights in which you wish to preserve detail and, depending on your sensor characteristics, should be considering raising ISO to lower noise (again, without undesirable highlight clipping).

Thinking about the settings a photographer with another camera would use doesn't seem very productive.

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OP Great Bustard Forum Pro • Posts: 41,911
Re: Perhaps the real question should be.....
4

jalywol wrote:

Can you get the results you are looking for from the camera system you are using?

Yes, but that's 'cause I shoot FF. 

If you are a shallow DOF seeker, then FF is always going to be a better choice than M43.

I disagree.  While FF allows for a more shallow DOF and less noise than mFT, that doesn't mean that mFT doesn't do shallow DOF or has too much noise.

In fact, even for someone who loves shallow DOF and clean photos, they may find that mFT is "good enough" in that regard, so why put up with the size, weight, and cost of a FF system that has even more shallow DOF and lower noise still, when it won't make a noticable impact on their photography?

If you routinely shoot in very dark environs with no flash, the high ISO performance of a good FF sensor is going to be better than M43.

Again, not necessarily.  The better noise performance of FF comes at the expense of a more shallow DOF.  For the same DOF and shutter speed, FF has no noise advantage over mFT (indeed, FF is even at a disadvantage when using a lens that does not have IS and motion blur is not an issue).

If you want smaller, lighter lenses with a competent system, and the DOF differences are either an advantage (in the case of landscape and macro work), or not a significant factor in your style of shooting, then M43 is a remarkably adept option.

That's what I'm saying.

These are different tools.  Pick the one that works for your shooting style, or use both if needed. Don't try and make one into the other....just use the blasted cameras and if you find one does not do what you want in terms of DOF rendering, then realize you have to move to the other to get what you need out of it.

They are different tools, but can largely be used for the same purposes.  It's only for certain particular tasks that one has the clear advantage over the other.

Until the laws of physics change, and you can get a FF sensor into an M43 body with M43 size lenses, then the compromises you make for portability are going to be in the DOF and sensor noise area.  As technology improves, the sensor noise issues are going to also continue to improve, so that may become a non-issue at some point, too (look how far we have come in terms of high ISO performance in the M43 in the past two years, for example.  I can now actually get good quality images at ISO 3200, and can relax about using ISO 1600 without having to worry about the color washing out or significant detail loss to noise...and future sensor performance will improve yet again on that.)

All systems continue to expand the envelope, although there are physical limits to what can be done.  The question, then, is how large an envelope you need for your photography.

I frequently feel that this particular argument is perpetuated by non-M43 users who are trying to prove how INCOMPETENT M43 is to make themselves feel better about their own DSLR choices.  I often wonder what cameras the loudest equivalence complainers have....are they really FF users, or are they APS-C users trying to justify the small gains in DOF of their APS-C models over M43?  Perhaps the answer to these arguments should simply be: Why not try out the M43 cameras and lenses and see if they work for you?  No point in getting into this fray again and again.....

In my opinion, best to acknowledge the differences between the systems based on the both the facts and the types of photos one takes.  That is, while one system may clearly be superior to another for a particular purpose, if that particular purpose is not an aspect of your photography, then it has no bearing for you.

For example, someone might say, "The 70-200 / 2.8 on FF is equivalent to a 35-100 / 1.4 on mFT".  A good response might be, "Sure.  But I don't need an aperture that wide, and the significantly smaller size, weight, and cost of the mFT option suits my needs much better.  For example, I would be uncomfortable pointing a D600 + 70-200 / 2.8 VR II at someone in a crowd, whereas I feel very comfortable doing that with my EM5 + 35-100 / 2.8."

69chevy Senior Member • Posts: 1,617
Re: Crop factors and Equivalents

Great Bustard wrote:

69chevy wrote:

So...

My camera phone has a crop factor of 7.64, the lens is 3.85mm and the aperture is f2.4.

The FF equivalent is 30mm f2.4?

No -- the FF equivalent is 29mm f/18 (3.85mm x 7.64 = 29mm, f/2.4 x 7.64 = f/18).

No disrespect, but if you are strictly talking DOF, this makes a little sense. If you are talking about diffraction effects or exposure effects it is not true.

Why bother comparing different formats?

Why compare different anything?  That said, there's no point in bringing up Equivalence if you are not comparing different formats.

That was my point, I don't see the point in comparing different formats.

If you use both, you should still know the FOV of all of your lenses from experience.

One would hope that you know more than just the FOV.

That is all you will get from these comparisons, so it is all you need to know to avoid them.

Apples and Oranges if you ask me (which you didn't).

More like V8s and in-line 4s, actually.

Which are also so different that comparisons are of little use. "My Honda has a .3 Corvette equivalence factor"...

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Anders W Forum Pro • Posts: 21,468
Re: The role of ISO

Great Bustard wrote:

Dr_Jon wrote:

The only issue I have with all the equivalence talk, other than that it is the the topic that "keeps on giving" is that when I put a 70-200 f.28 lens on my FF camera my first thought isn't "Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops".

Although it is fair to say GH3 ISO is really equivalent to a bigger number than FF ISO in some ways (i.e. noise) and just reflects the smaller sensor needs more "gain" to get the exposure and so the ISO is just what makes the maths work. (People do seem to see ISO as some thing that is equivalent between systems, rather than being implemented as a fudge-factor to make exposure maths work).

First of all, please take a read of gollywop's outstanding post on exposure to see what ISO is all about:

http://www.dpreview.com/forums/post/51136862

Secondly, if "when I put a 70-200 f.28 lens on my FF camera my first thought isn't 'Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops'." then you are thinking wrong.

Instead, you should be thinking that FF will use two stops higher ISO than mFT for the same DOF and shutter speed as mFT.  But often, when there is ample light, FF will be able to shoot whatever DOF they want and use a lower shutter speed than mFT.

For example, while the FF photographer might shoot 200mm f/5.6 1/400 ISO 1600 as opposed to 100mm f/2.8 1/400 ISO 400 on mFT, they might also shoot at 200mm f/5.6 1/400 ISO 100 as opposed to 100mm f/2.8 1/1600 ISO 100 on mFT, light permitting.

Not if you have this:

http://www.dpreview.com/forums/post/51133125

By such means the MFT photographer in the second of your two examples would be able to lower the shutter speed to the same level as the FF shooter (1/400), lower the effective ISO to two EV below that used by the FF photographer (ISO 25 versus ISO 100), and reap at least some of the potential benefits of the increased exposure. That is the point of the magenta filter that you were wondering about.

That said, I am looking forward to arbitrarily low camera ISOs (without read-noise penalties). That would effectively eliminate any FF advantage in ample-light shooting (except when DoF is in very low demand). There are some hopeful signs on the horizon here:

http://www.dpreview.com/news/2013/02/27/rambus-shows-binaryt-pixel-sensor-technology-for-expanded-dynamic-range

http://www.pixim.com/products-and-technology/technology

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OP Great Bustard Forum Pro • Posts: 41,911
Re: The role of ISO

richarddd wrote:

Great Bustard wrote:

Dr_Jon wrote:

The only issue I have with all the equivalence talk, other than that it is the the topic that "keeps on giving" is that when I put a 70-200 f.28 lens on my FF camera my first thought isn't "Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops".

Although it is fair to say GH3 ISO is really equivalent to a bigger number than FF ISO in some ways (i.e. noise) and just reflects the smaller sensor needs more "gain" to get the exposure and so the ISO is just what makes the maths work. (People do seem to see ISO as some thing that is equivalent between systems, rather than being implemented as a fudge-factor to make exposure maths work).

First of all, please take a read of gollywop's outstanding post on exposure to see what ISO is all about:

http://www.dpreview.com/forums/post/51136862

Secondly, if "when I put a 70-200 f.28 lens on my FF camera my first thought isn't 'Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops'." then you are thinking wrong.

Instead, you should be thinking that FF will use two stops higher ISO than mFT for the same DOF and shutter speed as mFT.  But often, when there is ample light, FF will be able to shoot whatever DOF they want and use a lower shutter speed than mFT.

For example, while the FF photographer might shoot 200mm f/5.6 1/400 ISO 1600 as opposed to 100mm f/2.8 1/400 ISO 400 on mFT, they might also shoot at 200mm f/5.6 1/400 ISO 100 as opposed to 100mm f/2.8 1/1600 ISO 100 on mFT, light permitting.

In any camera, you should be setting exposure to maximize light on the sensor consistent with desired DOF and motion blur, but without clipping highlights in which you wish to preserve detail and, depending on your sensor characteristics, should be considering raising ISO to lower noise (again, without undesirable highlight clipping).

Indeed.  I believe there was a nice post on that point:

http://www.dpreview.com/forums/post/51136862

Thinking about the settings a photographer with another camera would use doesn't seem very productive.

Not productive when using the camera, but productive when choosing between systems.

OP Great Bustard Forum Pro • Posts: 41,911
Please...
1

69chevy wrote:

Great Bustard wrote:

69chevy wrote:

So...

My camera phone has a crop factor of 7.64, the lens is 3.85mm and the aperture is f2.4.

The FF equivalent is 30mm f2.4?

No -- the FF equivalent is 29mm f/18 (3.85mm x 7.64 = 29mm, f/2.4 x 7.64 = f/18).

No disrespect, but if you are strictly talking DOF, this makes a little sense. If you are talking about diffraction effects or exposure effects it is not true.

...read the OP.  It's all discussed there (and yes, diffraction and exposure are discussed).

thinkfat Senior Member • Posts: 1,185
My own explanation of equivalence ...

... is much shorter and fits into one paragraph

Think of a full frame sensor behind a lens of certain focal length and aperture. Then crop the resulting image to the format of the "equivalent" systems sensor.

To stay with your original setup, think of a 35-100/2.8 lens on a FF sensor, crop to the size of a mFT sensor, watch equivalence reveal itself.

Covers everything but diffraction nicely. Add some more pixels and it also covers diffraction

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forpetessake
forpetessake Veteran Member • Posts: 4,892
Re: A few words on Equivalence and comparing systems

Just another Canon shooter wrote:

BTW, one thing that is not equivalent is the price. The 35-70/2.8 costs more that the 70-200/4 Canon or Nikon, and it is equivalent to 70-200/5.6. This is despite the Canon/Nikon lenses having built in IS. At least it is lighter.

The actual equivalent to the 70-200/4 is the Olympus 35-100mm f/2.0 Zuiko. It is a 3.6 lb monster, vs. 1.67 lb for the Canon, and costs twice as much. So twice the weigh and twice the price for an equivalent lens which cannot even match the performance of its f/4 equivalent.

What the release of smaller lighter DSLRs in recent years indicate is that we are going to see a slower lighter FF lenses in the future. The low end market shows the willingness to trade performance for weight. Something like FF 70-200/5.6 can be made very small and light, theoretically lighter than Panasonic 35-100, probably longer at 200mm, but if the lens is collapsible it's a non-issue. And since the price of such lenses would be a fraction of Panasonic, they could be sold in millions.

In the past slow lenses were not requested by the market, now with the sensor technology improving so much and the sensor prices falling, that will be a reality. As it is always the case in technology, silicon drives away glass and metal and manual labor.

OP Great Bustard Forum Pro • Posts: 41,911
Re: My own explanation of equivalence ...
1

thinkfat wrote:

... is much shorter and fits into one paragraph

Think of a full frame sensor behind a lens of certain focal length and aperture. Then crop the resulting image to the format of the "equivalent" systems sensor.

To stay with your original setup, think of a 35-100/2.8 lens on a FF sensor, crop to the size of a mFT sensor, watch equivalence reveal itself.

Indeed.  If we took a photo at 100mm f/2.8 on FF, and cropped it to the same framing as a photo taken at 100mm f/2.8 on mFT, the photos would be equivalent (although the mFT photo would be more detailed since the sensor has a higher pixel density and the lens is sharper).

Covers everything but diffraction nicely. Add some more pixels and it also covers diffraction

Actually, the effects of diffraction softening are also included, and the pixel size has nothing to do with it:  the proportion of the photo that the Airy Disk takes up when the FF photo is cropped by a factor of two also doubles (as does the DOF when the photo is displayed at the original size).

That is, if we took two photos with FF, one at 200mm f/5.6, the other at 100mm f/2.8, but cropped the 100mm f/2.8 photo to the same framing as the 200mm f/5.6 photo, and displayed them at the same size, the amount of diffraction softening would be the same, as would the DOFs.

richarddd
richarddd Veteran Member • Posts: 3,101
Re: The role of ISO

Great Bustard wrote:

richarddd wrote:

Great Bustard wrote:

Dr_Jon wrote:

The only issue I have with all the equivalence talk, other than that it is the the topic that "keeps on giving" is that when I put a 70-200 f.28 lens on my FF camera my first thought isn't "Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops".

Although it is fair to say GH3 ISO is really equivalent to a bigger number than FF ISO in some ways (i.e. noise) and just reflects the smaller sensor needs more "gain" to get the exposure and so the ISO is just what makes the maths work. (People do seem to see ISO as some thing that is equivalent between systems, rather than being implemented as a fudge-factor to make exposure maths work).

First of all, please take a read of gollywop's outstanding post on exposure to see what ISO is all about:

http://www.dpreview.com/forums/post/51136862

Secondly, if "when I put a 70-200 f.28 lens on my FF camera my first thought isn't 'Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops'." then you are thinking wrong.

Instead, you should be thinking that FF will use two stops higher ISO than mFT for the same DOF and shutter speed as mFT.  But often, when there is ample light, FF will be able to shoot whatever DOF they want and use a lower shutter speed than mFT.

For example, while the FF photographer might shoot 200mm f/5.6 1/400 ISO 1600 as opposed to 100mm f/2.8 1/400 ISO 400 on mFT, they might also shoot at 200mm f/5.6 1/400 ISO 100 as opposed to 100mm f/2.8 1/1600 ISO 100 on mFT, light permitting.

In any camera, you should be setting exposure to maximize light on the sensor consistent with desired DOF and motion blur, but without clipping highlights in which you wish to preserve detail and, depending on your sensor characteristics, should be considering raising ISO to lower noise (again, without undesirable highlight clipping).

Indeed.  I believe there was a nice post on that point:

http://www.dpreview.com/forums/post/51136862

If someone tried to think of that when putting a lens on their camera and trying to set the controls, they'd likely miss the shot.

Thinking about the settings a photographer with another camera would use doesn't seem very productive.

Not productive when using the camera, but productive when choosing between systems.

Agreed, however "when I put a 70-200 f.28 lens on my FF camera my first thought" suggests someone using a camera, not choosing.

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jalywol
jalywol Veteran Member • Posts: 9,455
Re: Perhaps the real question should be.....

Great Bustard wrote:

In my opinion, best to acknowledge the differences between the systems based on the both the facts and the types of photos one takes.  That is, while one system may clearly be superior to another for a particular purpose, if that particular purpose is not an aspect of your photography, then it has no bearing for you.

That was the entire point of my post......

-J

OP Great Bustard Forum Pro • Posts: 41,911
Re: The role of ISO
1

richarddd wrote:

Great Bustard wrote:

richarddd wrote:

Great Bustard wrote:

Dr_Jon wrote:

The only issue I have with all the equivalence talk, other than that it is the the topic that "keeps on giving" is that when I put a 70-200 f.28 lens on my FF camera my first thought isn't "Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops".

Although it is fair to say GH3 ISO is really equivalent to a bigger number than FF ISO in some ways (i.e. noise) and just reflects the smaller sensor needs more "gain" to get the exposure and so the ISO is just what makes the maths work. (People do seem to see ISO as some thing that is equivalent between systems, rather than being implemented as a fudge-factor to make exposure maths work).

First of all, please take a read of gollywop's outstanding post on exposure to see what ISO is all about:

http://www.dpreview.com/forums/post/51136862

Secondly, if "when I put a 70-200 f.28 lens on my FF camera my first thought isn't 'Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops'." then you are thinking wrong.

Instead, you should be thinking that FF will use two stops higher ISO than mFT for the same DOF and shutter speed as mFT.  But often, when there is ample light, FF will be able to shoot whatever DOF they want and use a lower shutter speed than mFT.

For example, while the FF photographer might shoot 200mm f/5.6 1/400 ISO 1600 as opposed to 100mm f/2.8 1/400 ISO 400 on mFT, they might also shoot at 200mm f/5.6 1/400 ISO 100 as opposed to 100mm f/2.8 1/1600 ISO 100 on mFT, light permitting.

In any camera, you should be setting exposure to maximize light on the sensor consistent with desired DOF and motion blur, but without clipping highlights in which you wish to preserve detail and, depending on your sensor characteristics, should be considering raising ISO to lower noise (again, without undesirable highlight clipping).

Indeed.  I believe there was a nice post on that point:

http://www.dpreview.com/forums/post/51136862

If someone tried to think of that when putting a lens on their camera and trying to set the controls, they'd likely miss the shot.

These are not things you think when taking the shot, but things that a competent photographer would have internalized and simply do it.  That said, many take some very nice photos in Auto mode. 

Thinking about the settings a photographer with another camera would use doesn't seem very productive.

Not productive when using the camera, but productive when choosing between systems.

Agreed, however "when I put a 70-200 f.28 lens on my FF camera my first thought" suggests someone using a camera, not choosing.

Which is why I said:

Secondly, if "when I put a 70-200 f.28 lens on my FF camera my first thought isn't 'Ah, the sensor is twice the area of my GH3 so I should immediately crank up the ISO two stops'." then you are thinking wrong.

69chevy Senior Member • Posts: 1,617
Re: Please...

Great Bustard wrote:

69chevy wrote:

Great Bustard wrote:

69chevy wrote:

So...

My camera phone has a crop factor of 7.64, the lens is 3.85mm and the aperture is f2.4.

The FF equivalent is 30mm f2.4?

No -- the FF equivalent is 29mm f/18 (3.85mm x 7.64 = 29mm, f/2.4 x 7.64 = f/18).

No disrespect, but if you are strictly talking DOF, this makes a little sense. If you are talking about diffraction effects or exposure effects it is not true.

...read the OP.  It's all discussed there (and yes, diffraction and exposure are discussed).

I did.

You can compare diffraction between two cameras with the same entrance pupil and different sensor sizes, but not with different flange distances and sensor sizes. This is where your equivalency formula falls short.

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forpetessake
forpetessake Veteran Member • Posts: 4,892
Re: A few words on Equivalence and comparing systems

MatsP wrote:

Just another Canon shooter wrote:

No. The Olympus 40-150 is sharper, I would even say a lot sharper, than the EF-S 55-250. I had that lens once but I sold it. It's well regarded but I was disappointed. The 40-150 is astonishingly good, and if you think of the price for it it's almost unbelievable.

In all respects  that GB listed the 40-150 is equivalent to a FF 80-300/8-11,2, but when I take a picture with it I regard it as a 40-150/4-5,6, which it is, and it gives me the same FOV and same exposure. But deeper DOF and a little more noise, theoretically at least.

You can look at another APS-C lens which is much closer to Olympus 40-150/4-5.6 (FF eq. 80-300/8-11.2), that is Sony 55-210/4.5-6.3 (FF eq. 82.5-315/6.75-9.45): http://www.dpreview.com/products/compare/side-by-side?products=sony_e_55-210_4p5-6p3&products=oly_m_40-150_4-5p6_r

The lens, not surprisingly, has better resolution on APS-C than Olympus on m4/3. The lens is longer and heavier, though as a part of the system it's hardly noticeable, but it's also 40% faster, and unlike Olympus it has high build quality with metal barrel. I would expect if the manufacturer used plastic and made lens slower it would have been the same weight as Olympus, though I'm sure the buyers would rather opt for 5 oz extra weight in exchange for better image quality, build, and speed.

OP Great Bustard Forum Pro • Posts: 41,911
Re: Please...
1

69chevy wrote:

Great Bustard wrote:

69chevy wrote:

Great Bustard wrote:

69chevy wrote:

So...

My camera phone has a crop factor of 7.64, the lens is 3.85mm and the aperture is f2.4.

The FF equivalent is 30mm f2.4?

No -- the FF equivalent is 29mm f/18 (3.85mm x 7.64 = 29mm, f/2.4 x 7.64 = f/18).

No disrespect, but if you are strictly talking DOF, this makes a little sense. If you are talking about diffraction effects or exposure effects it is not true.

...read the OP.  It's all discussed there (and yes, diffraction and exposure are discussed).

I did.

Excellent.  Then you understand that the efffects of diffraction softening and the total amount of light falling on the sensor is the same for 3.85mm f/2.4 on a 7.64x sensor as 29mm f/18 on a FF sensor for a the same shutter speed.

You can compare diffraction between two cameras with the same entrance pupil and different sensor sizes, but not with different flange distances and sensor sizes. This is where your equivalency formula falls short.

Um, no.  For more reading on diffraction and how it relates to different formats:

http://www.josephjamesphotography.com/equivalence/index.htm#diffraction

forpetessake
forpetessake Veteran Member • Posts: 4,892
No you did not, or ...
1

69chevy wrote:

Great Bustard wrote:

69chevy wrote:

Great Bustard wrote:

69chevy wrote:

So...

My camera phone has a crop factor of 7.64, the lens is 3.85mm and the aperture is f2.4.

The FF equivalent is 30mm f2.4?

No -- the FF equivalent is 29mm f/18 (3.85mm x 7.64 = 29mm, f/2.4 x 7.64 = f/18).

No disrespect, but if you are strictly talking DOF, this makes a little sense. If you are talking about diffraction effects or exposure effects it is not true.

...read the OP.  It's all discussed there (and yes, diffraction and exposure are discussed).

I did.

You can compare diffraction between two cameras with the same entrance pupil and different sensor sizes, but not with different flange distances and sensor sizes. This is where your equivalency formula falls short.

You either didn't read or did not understand. If it's the latter, then there is no shame in asking questions, but making arrogant statements is a completely different matter.

forpetessake
forpetessake Veteran Member • Posts: 4,892
Re: Perhaps the real question should be.....

Great Bustard wrote:

jalywol wrote:

Can you get the results you are looking for from the camera system you are using?

Yes, but that's 'cause I shoot FF. 

If you are a shallow DOF seeker, then FF is always going to be a better choice than M43.

I disagree.  While FF allows for a more shallow DOF and less noise than mFT, that doesn't mean that mFT doesn't do shallow DOF or has too much noise.

In fact, even for someone who loves shallow DOF and clean photos, they may find that mFT is "good enough" in that regard, so why put up with the size, weight, and cost of a FF system that has even more shallow DOF and lower noise still, when it won't make a noticable impact on their photography?

If you routinely shoot in very dark environs with no flash, the high ISO performance of a good FF sensor is going to be better than M43.

Again, not necessarily.  The better noise performance of FF comes at the expense of a more shallow DOF.  For the same DOF and shutter speed, FF has no noise advantage over mFT (indeed, FF is even at a disadvantage when using a lens that does not have IS and motion blur is not an issue).

It's an interesting way of looking at different systems. Given the same FOV, DOF, the ideal lenses for all systems create equivalent images. Of course, there are no ideal lenses, and lenses for larger sensors are easier to make.

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