Do the math - focal length and Format demystified

[psy501]

..maybe there are things i did not get right..but what strikes me about this video is that no matter how big the sensor involved is what matters is the size of the photosites and therefore their ability to gather photons..so i think he tries to condense things in a way that 'the smaller sensor doesnt gather that much light' which is wrong..what matters is how big the sites are..

..i think most of the members involved here talk about and mean the same thing but nomenclatura divides them..

 

[Viramati]

About as interesting and informative as the Leica T polishing video. At least it was 5 minutes shorter but I lost interest after about a minutes viewing

 

[jaree]

Maybe we can have a separate "Tech Talk" forum where the intricacies of the sensor size, photo-diodes, S/N ratio and such can be discussed - I do see that it could be fascinating for some members. That will be all so far my contribution to this thread is concerned.

 

[fotografz]

Quite amazing the passion that erupts around the alchemy of photography.

It'd be interesting to hear from someone that actually knows what they are talking about … like a real live optical designer for example.

Me? I hated higher math classes, just squeaked by mostly because I used the time to draw rather than memorize theorems and axioms. I didn't have to pass a math test to get into Art School, my drawings got me in.:thumbup:

I'm a visual person … seeing is believing. I started using a FF sensor the minute they became available, and MFD the minute I could afford one. I like the way they look, I don't like the way dinky frames look. Technology hasn't changed that. What it has changed is the bigger sensors can now be had in a smaller camera … that's the sort of math I like.:thumbs:

- Marc

 

[Georg Baumann]

I have not seen the video yet, will have a look later, but I read this thread and a question came to my mind why it so quickly develops to a point that the original poster feels he has to leave it.

Hence I was wondering wether this is a chat about religion/politics/sex, all three forbidden subjects to talk about in real Irish pubs, or a chat about the art of capturing electromagnetic radiation?

Well as Guy is around the corner, and has nothing else to do , he could present the video to About OSC | College of Optical Sciences | The University of Arizona and ask about their take on it.

Stefan is making the somewhat bold claim that Olympus and MFT are lying about their lenses, I am going to have a look at this video.

 

[fotografz]

… Well as Guy is around the corner, and has nothing else to do , he could present the video to About OSC | College of Optical Sciences | The University of Arizona and ask about their take on it.

Stefan is making the somewhat bold claim that Olympus and MFT are lying about their lenses, I am going to have a look at this video.

My point exactly. Someone whom can speak to the subject with reason and logic, and has no dog in the hunt. Even a university senior majoring in optical sciences should be able to shed light on the subject

I took the implication to be "Lies of Omission" … that an equivalent translation from 35mm FF size to a sub-35mm sized sensor should not only speak to the focal length equivalent, but also the "effective" aperture and its influence on the image.

The "standard of common understanding" is based on the 135 film format that dominated for most of photographic history. Digital started with crop frame sensors, and most photographers already had lenses for FF coverage. Thus the base of confusion was established.:facesmack:

Those who say "who cares" may be the only ones that are right.

- Marc

 

[Georg Baumann]

Northrup is what? The brother of the Dog Whisperer :ROTFL: or

In June, 2000, Northrup won the Sexiest Geek Alive contest.

Well, apart from that, he is regurgitaing Microsoft manuals, wrote 32 books about MS products and is a selfproclaimed tech expert. I can follow his logic that marketing departments make claims that do not reflect the reality of any given product, of course.

But he goes further and states Olympus, Panasonic and Sony are lying, while Canon, Nikon and Fuji are stating the truth. Right. Then at the end of his selfpromotion video something struck me. He refers products from Voiglander, Sigma, Metabones, etc. and shows a link to follow like:

sdp dot io slash booster.

Dot io? Yeah right, here is what happens when I follow these links. I end up at the amazon product page.

Personally I do not have a good impression of this chap. In my view it is a covered up product evangelist video, a business.

To use his own words at the end of the video and frame them in my own statement, "So don't get tricked by a sleezy selfpromoter."

:facesmack:

 

[Annna T]

I took the implication to be "Lies of Omission" … that an equivalent translation from 35mm FF size to a sub-35mm sized sensor should not only speak to the focal length equivalent, but also the "effective" aperture and its influence on the image.

The "standard of common understanding" is based on the 135 film format that dominated for most of photographic history. Digital started with crop frame sensors, and most photographers already had lenses for FF coverage. Thus the base of confusion was established.:facesmack:

Those who say "who cares" may be the only ones that are right.

- Marc

Personnally I find it way too exaggerated to say that mirrorless manufacturers are lying to their clients and cheating them. I was also thinking to the beginning of DSLRs. There were no FF for several years, but as long as the big two manufacturers were producing APSC DSLRs heavier than the FF film SLRs, none of them was accused of cheating their customers.

It is only since the the beginning of the small and light mirrorless (Panasonic, Olympus and Sony Nex, etc.) that people have brought that accusation forward. Those cameras have a big advantage in matters of size and weight. They are using the newest technology (EVF, mirrorless, focus peaking, magnifying, WISIVIG view of the pictures, state of the art sensors etc..) and all this is clearly creating a shift in the camera manufacturers' world (along with smartphones) and some who are in danger due to this evolution don't like it.

The debate has mostly dwelt with MFT versus FF in this thread, but the initial remark of Mr Steib - and probably the one he is most interested in - is that the same analyse is also valid when comparing FFs like the A7r and D800 to MFDB. IMO, the price difference, more than the size, is threatening for the MFDB industry. Of course those experienced photographers who uses MF or the D800 are fully aware of what the differences between the two kinds of systems will be; insinuating that they are cheated or that they are ignoring facts is rather insulting for them.

The question isn't whether the manufacturers of smaller sensors are cheating them, the question is whether the price/size advantages are big enough to compensate for the IQ differences, an IQ difference which is getting smaller and smaller.

 

[mazor]

wow, based on that video, I should sell all my micro four thirds gear in favor of fullframe, and full frame camera manufacturers should manufacturer smaller slow aperture tele zooms f8.0 or even f11 for those who want lighter kit. I guess Sony as done it right by releasing f4.0 zoom lens variants for the A7 and A7r as it keeps the lens size down rather than making 2.8 versions.

 

[fotografz]

Personnally I find it way too exaggerated to say that mirrorless manufacturers are lying to their clients and cheating them. I was also thinking to the beginning of DSLRs. There were no FF for several years, but as long as the big two manufacturers were producing APSC DSLRs heavier than the FF film SLRs, none of them was accused of cheating their customers.

It is only since the the beginning of the small and light mirrorless (Panasonic, Olympus and Sony Nex, etc.) that people have brought that accusation forward. Those cameras have a big advantage in matters of size and weight. They are using the newest technology (EVF, mirrorless, focus peaking, magnifying, WISIVIG view of the pictures, state of the art sensors etc..) and all this is clearly creating a shift in the camera manufacturers' world (along with smartphones) and some who are in danger due to this evolution don't like it.

The debate has mostly dwelt with MFT versus FF in this thread, but the initial remark of Mr Steib - and probably the one he is most interested in - is that the same analyse is also valid when comparing FFs like the A7r and D800 to MFDB. IMO, the price difference, more than the size, is threatening for the MFDB industry. Of course those experienced photographers who uses MF or the D800 are fully aware of what the differences between the two kinds of systems will be; insinuating that they are cheated or that they are ignoring facts is rather insulting for them.

The question isn't whether the manufacturers of smaller sensors are cheating them, the question is whether the price/size advantages are big enough to compensate for the IQ differences, an IQ difference which is getting smaller and smaller.

While I appreciate the POV, I wouldn't go so far as to dismiss alternative forms of photographic tools in favor of the smaller wonder-cams.

IQ seems to be a constant source of debate, and IMO has become somewhat narrow in definition … personally, I've expanded IQ to mean "Image Qualities" because that is what I am FAR more interested in as opposed to anal-yzing pixel peeping resolution measurements … which most digital cameras/premium optics now deliver to one degree or another, and most of us would certainly agree isn't lacking in most.

My Sony A7R is a 35mm full frame 36 meg camera, and my Leica S2P is a larger sensor 37 meg camera … given the much touted 55/1.8 Zeiss FE lens and the excellent Leica S optics … they should be quite similar, but aren't.

In short, I see Image Characteristics from my Leica that I favor well above the Sony, even in an 8X10 print. Why? I haven't a clue, I'm not a scientist nor pretend to be one. In all honesty do not I care why and wouldn't spend the time to figure it out just to win some forum debate. It is just a "visual fact" for me.

The method of measurement I use are my experienced and critical eyes … which I trust more than endless e-words and images of brick walls and test charts. Sometimes I feel we are collectively becoming "tech drones", and have forgotten the vast variables of making an image that meets our creative sensitivities and vision. How does some tool match up with us as visually creative individuals?

I could rationally go on about the Leica being a dual shutter camera, and that it shoots to two cards, and has a simple interface that seems to escape the Sony designers and other "swiss knife" entries in the smaller cam category, but the real reason is the Image Characteristics … because in the end THAT is all that counts to me.

Others may feel the same about the camera they favor whatever it may be, and I respect that. However, it has absolutely nothing to do with my preferences, nor does it invalidate my choice of tools irrespective of price, or any other aspect, do-dad, size … other than Image Characteristics.

- Marc

 

[pegelli]

Personnally I find it way too exaggerated to say that mirrorless manufacturers are lying to their clients and cheating them.

In my mind it's further that that, it's plain wrong. All phenomena discussed are governed by the laws of physics and optics. How can it be cheating if that's what's happening. Yes there are key differences between formats, well documented in good scientific and photographic literature but they are very far away from cheating. In the end it will influence IQ (as fotografz pointed out) but it also reminds me of AA's stern advice: "there is nothing worse than a sharp picture of a fuzzy concept".

I think the only cheats are the people who are blowing this "problem" out of proportion with half truth and omitting key information because it suits their story (or sales) better.

 

[Stefan Steib]

I just spoke about this with Dietmar Wüller of Image Engineering (probably one of the few experts worldwide besides People like Dr. Nasse from Zeiss maybe - which I will also try to ask about it....as I can ) for maybe 15minutes now
.
The problem is:
1) it is additionally scale dependent, macro will differ from infinity
2) there are some other formulas involved to make it scientifically stringent
and thus there is no SINGLE Formula where you can calculate this.

Fact is though: if you look at the Image appearance, this is definitely right as the video describes it. Or as Lloyd descibes it.
The part with the photons (differing exposure), amount of exposure is completely left out to trial and error, as there are no correllating data for any sensors available (at least not in easy Public access) that could be used to define this.

He gave me a link for the formulas he once descibed for depth of field on differing formats, which is kind of a mathematical proof for the part of the differing depth of field (in german only-sorry), but as there are so many superior math geniuses around here, they may easily understand the formulas without an english explanation....

» Blog Archiv » Schärfentiefe

Greetings from Germany
Stefan

 

[johnnygoesdigital]

MFDB will slowly become obsolete, just like 4x5 and 8x11 view cameras. Offering a small portable view camera able to mount an A7r in the rear standard could be a hit

The question isn't whether the manufacturers of smaller sensors are cheating them, the question is whether the price/size advantages are big enough to compensate for the IQ differences, an IQ difference which is getting smaller and smaller. Anna T

Fotodiox has adapters to mount FF to 4x5. Pair this with an Ebony or Chamonix, and you have a very portable 4x5 dslr.

http://www.bhphotovideo.com/bnh/con...I3JhZy-ur4CFaVQOgoduxEAyA&Q=&is=REG&A=details

This discussion is likely too esoteric for the photographer/artist who find these drawn out threads to be less controversial. I often find the most technical photographers tend to have the most boring portfolios anyway. I think Stefan was just trying to share something he thought interesting. Go film...

 

[Chuck Jones]

Ok, so now I watched the video. Best entertainment I've seen since reviewing the footage with my dentist at my last root canal.

By this guy's calculations my 8x10 Sinar P2 was the only honest camera I ever owned. But only when I had that huge Nikkor T 800mm f/12 ED mounted up in that Copal 3 shutter.

All the rest of my cameras have been lying to me! I always knew there was something sneaky that lived inside those old 'Blads, but I never suspected gremlins living in my new Sony A7R! :wtf:

This stuff just makes my brain hurt. I don't see the art in any of it.

:worthless:

 

[Godfrey]

Boy, this thread continues to amaze me.

When I shoot with film, I shoot with everything from 8x11mm Minox format to 6x9cm medium format cameras. Who's lying to me then about focal length and aperture?

Same thing with digital capture. There are a bunch of interchangeable lens camera formats ... from 1" like the Nikon 1 to FT to APS-C to FF to MFDB and LF scanning backs.

The only people who can be interpreted as lying about anything are people who believe in this idiotic "35mm FF über alles" supremacy and insist that anything that looks vaguely like a 35mm film camera MUST BE a 35mm format or it isn't what its manufacturer says it is.

Different formats have different sizes, which influences lens physical size, field of view of the same focal length lenses across formats, Depth of Field, imaging characteristics, etc etc. It is no different from how it always was in the film world except this "35mm FF über alles" nonsense wants to make it different for some unknown (and likely marketing-money driven) reason.

Same for this insane OCD discussion of "Image Quality". As someone else said along the way, I don't nave to reduce every photograph to some arcane set of specifications of contrast, resolution, MTF curves, mid-tone micro contrast, dynamic range deliberation, et cetera ad nauseam to say "Hey, that's a good photograph! I like it!" I can recognize with my eyes a good lens from a bad one, a good rendering from a bad one, well enough.

I know enough about sensors, optics, formats, FoV, DoF, etc that I don't need some engineer to tell me how basic photographic principles work. Never mind some video blogger rambling on nonsensically about how one camera company is lying compared to another.

Enough of this nonsense for me. I'm quite happy with how my cameras perform, with how the pictures I make appear, from whatever format I choose to work with. And I don't need to debate whether one is lying to me or not in the perception of people whom I wouldn't listen to anyway if they sat in the pulpit at the local evangelical tent.

G

 

[Stefan Steib]

Chuck -

well it probably depends on what you are demanding for your money ?

Lets say you go to your Photodealer of your choice and want to buy a brand new LEICA DG NOCTICRON 1,2/42,5mm H-NS043 for whopping 1500 € (around 2000 $ US).
At home you shoot this lens and (it may or may not equal absolute exposure depending on the technology of your used MFT sensor, most likely it will NOT be the same as most new FF 24x36 sensors) but even worse - the image does not look like a f1,2/85mm (which is the actual used terminology in ads) but exactly like a 2.0/85mm on 35mm FF - both on open aperture (added to clarify even more !!!) ?

Wouldn´t you feel cheated ? Especially as a good 2,0/85mm from Nikon, Canon or SonyFF costs only about 1-/4th to 1/5th of this ?

Of course this lens may be the best of the best and you say you don´t care if it is so superior, but additionally you are limited to 16 Mpix resolution whereas the 24x36 FF rise to 36mpix ?

Totally out of relevance ?

Really ?

 

[Leigh]

At home you shoot this lens and (it may or may not equal absolute exposure depending on the technology of your used MFT sensor, most likely it will NOT be the same as most new FF 24x36 sensors) but even worse - the image does not look like a f1,2/85mm (which is the actual used terminology in ads) but exactly like a 2.0/85mm on 35mm FF ?

Have you entered an "equivocation of the week" contest?

... may or may not ...
... most likely ...

And, from an earlier post (at 15:17):
"Guy - this will be my last post in this thread."

Seems we can't believe anything you post.

-----

It seems Godfrey and I agree for once.
I shoot Ilford FP4+ in all formats from 35mm through 8x10, and get exactly the same results using many different lenses.

I also shoot digital in formats from toys through medium (Hasselblad).
Exposures (based on nominal ISO speed) are consistent throughout that range.

Stefan, I fail to understand what point you may be trying to make.

- Leigh

 

[Stefan Steib]

Stefan, I fail to understand what point you may be trying to make.

- Leigh

Yes - I see that you don´t understand.

Greetings from Germany
Stefan

 

[Godfrey]

Chuck -

well it probably depends on what you are demanding for your money ?

Lets say you go to your Photodealer of your choice and want to buy a brand new LEICA DG NOCTICRON 1,2/42,5mm H-NS043 for whopping 1500 € (around 2000 $ US).
At home you shoot this lens and (it may or may not equal absolute exposure depending on the technology of your used MFT sensor, most likely it will NOT be the same as most new FF 24x36 sensors) but even worse - the image does not look like a f1,2/85mm (which is the actual used terminology in ads) but exactly like a 2.0/85mm on 35mm FF ?

Wouldn´t you feel cheated ? Especially as a good 2,0/85mm from Nikon, Canon or SonyFF costs only about 1-/4th to 1/5th of this ?

Of course this lens may be the best of the best and you say you don´t care if it is so superior, but additionally you are limited to 16 Mpix resolution whereas the 24x36 FF rise to 36mpix ?

Totally out of relevance ?

Really ?

Yes. Really.

G

 

[Chuck Jones]

Chuck -

well it probably depends on what you are demanding for your money ?

Lets say you go to your Photodealer of your choice and want to buy a brand new LEICA DG NOCTICRON 1,2/42,5mm H-NS043 for whopping 1500 € (around 2000 $ US).
At home you shoot this lens and (it may or may not equal absolute exposure depending on the technology of your used MFT sensor, most likely it will NOT be the same as most new FF 24x36 sensors) but even worse - the image does not look like a f1,2/85mm (which is the actual used terminology in ads) but exactly like a 2.0/85mm on 35mm FF ?

Wouldn´t you feel cheated ? Especially as a good 2,0/85mm from Nikon, Canon or SonyFF costs only about 1-/4th to 1/5th of this ?

Of course this lens may be the best of the best and you say you don´t care if it is so superior, but additionally you are limited to 16 Mpix resolution whereas the 24x36 FF rise to 36mpix ?

Totally out of relevance ?

Really ?

Hi Stefan,
First off, let's dial back the rhetoric a notch or two, and make sure we are all talking about the same thing, because from the vitriol in this thread we clearly are not.

You and your friend that made the video are looking at the glass half full. I'm not even looking at a glass, I am looking at a set of tools, if you get my drift. I hear your objections, and understand your possibly valid concerns about how the industry chose to express its arcane wisdom over time. Remember though before tossing the whole baby out with the bathwater, there is a lot of history behind those choices. History for creating beautiful, well crafted images, not animated pixel comparison graphs or charts.

You ask do I have concern about a LEICA DG NOCTICRON 1,2/42,5mm on my GH3 not looking like an f1,2/85mm on my Canon 5D Mark III? No, actually I am not. If it did, it wouldn't be any dang good to me either, because Canon already has that covered with the excellent Canon 85mm f/1.2. You've got it backwards.

I would buy the LEICA DG NOCTICRON 1,2/42,5mm for my GH3 to go the OTHER way. In other words, @f8 using the Nocticron, I get total depth of field EXTENDED by two stops, closeup to infinity. Don't forget, in a filmmakers bag of tricks, different sensor sizes are great creative tools as well. You may not like the laws of physics, but we all have to live by them, and to be better photographers, learn to use them to our creative advantage.

If I wanted an 85mm f/1.2 look, I would pull out a 5D Mark III with a Canon 85mm f/1.2. I don't horse around with all those "math computations" your talking about when I am out shooting, nor do I carry my Captain America secret decoder ring. I carry a good light meter, a complete set of primes, a vision of what I want, and the experience collected over the years to help guide me in choosing the right camera sensor size, correct angle, and correct lenses to capture it - at the correct exposure.

I don't have the luxury of the time to run an Excel spreadsheet to compute anything. My clients rightly expect I get familiar with my gear, learn how to use it and what it can do in my own time, and then show up ready to complete the work I contracted with them to produce.

As a DP, I am responsible for deciding I need a GH3 & 12mm @f/2.8 for the look I am after. Or alternatively, maybe it is an 85mm f/1.2 Canon 5D Mark III look that is called for. Both are equally valid options, and both equally exclusive each to the other. I can't get the GH3 to look like the 5D anymore than I can get the 5D to look like the GH3. Or the Fuji X-E1 or the Sony A7R or the tiny Zoom Q4. They all look different, even with the same lens and the best grading suite in the business. MF & LF, same thing. Formats are options too.

What you seem to be saying is a conspiracy by camera manufacturers to somehow cheat the population, I as an artist see as viable creative options I wouldn't want to loose. Hope that helps to understand where some of us are coming from, and what we consider is relevant.