Comprehensive Blind Test for Lens, format, camera, and photography in general

I read a lot of theorist talks about photography that I find it dubious, suspicious if not pretentious. Such as:

 

1) 35mm/medium/large format have a different look

2) 50mm lens distort portrait more than 75mm, which in theory is true, but I can't tell the difference by my naked eye.

3) Image sharpness varies at different F stop for the same lens.

4) As well as, beat to death debate of film looks different than digital. ( I'm talking about color graded film stocks used for motion picture specifically)

 

And I really wish someone had done some comprehensive blind test with the so-called "Professional Photographers" and show me that given the same image, they can really tell

1) which one is shot on 35/medium/large

2) 50mm or 75mm or 80mm in terms of distortion

3) sharpness at different F stops

4) whether it is shot on film or digital for the same scene.

 

I hope I'm not being negative, but if I honestly can not tell the difference in sharpness they are talking about. They all look exactly the same.

 

IMAGE REMOVED

 

Nor, the discussion about which camera has what sensor, like found here: Can You Guess Which Camera Took Which Picture?

 

But even if you can tell the difference, tell me you didn't stare at it for long, and actively look for the minute details. In a real life situation, (especially motion pictures), how is anyone able to tell the difference really befuddles me.

 

Is this theoretical talk all gimmicks that people/ organizations use to keep themselves relevant?

 

Are there other people think the same or would like to defend themselves?

 

Thanks for you input.

Edited August 21, 2020 by William Michael

Much is below the level that you can see on a screen or small print. Rest assured that you can easily tell the difference between 35 mm film and 4x5 film (or larger) on 11 x 14 inch prints. Lens performance differences are easily seen using test charts, but may or may not show up in your prints. Going the other way, no, it's not usually possible to look at prints and say what lens was used. "Distortion" in portraits has to do with where you stand. The lens is only chosen to get a suitable image size. That's actually true more often than not. A zoom lens is not equal to "sneaker zoom" where you change where you're standing. No double blind testing needed; this stuff is all well described and documented. Bokeh? Well, that one has so many variables that nobody will ever sort it out, but I know good and bad when I see it.

Much is below the level that you can see on a screen or small print. Rest assured that you can easily tell the difference between 35 mm film and 4x5 film (or larger) on 11 x 14 inch prints. Lens performance differences are easily seen using test charts, but may or may not show up in your prints. Going the other way, no, it's not usually possible to look at prints and say what lens was used. "Distortion" in portraits has to do with where you stand. The lens is only chosen to get a suitable image size. That's actually true more often than not. A zoom lens is not equal to "sneaker zoom" where you change where you're standing. No double blind testing needed; this stuff is all well described and documented. Bokeh? Well, that one has so many variables that nobody will ever sort it out, but I know good and bad when I see it.

 

1)"Distortion" in portraits has to do with where you stand.

Could you elaborate?

 

2) Rest assured that you can easily tell the difference between 35 mm film and 4x5 film (or larger) on 11 x 14 inch prints.

Hollywood movies are shot on 35mm 2 perf, 3 perf, 4 perf, and 65mm, 70mm, blown up to a 25ft screen at least.

There is a difference between 16mm and 70mm, absolutely, but I'd like to see someone tell me if something is shot on 35mm and 65mm without looking up imdb. Or even better, some movies are shot with 35mm and 65mm in different scene and "stitched" in the final print. Would anyone be kind to spot which scene is for which, in a movie theatre? That's way larger than a photo print on the table.

1)"Distortion" in portraits has to do with where you stand.

Could you elaborate?

I'll give my answer here, because it's something that I see often, this myth that lenses 'compress' distances. Even some cinematographers believe it!

 

Here's the thing: your original statement, "50mm lens distort portrait more than 75mm, which in theory is true", is false. I mean, 100% false (and distortion is a phenomenon that describes how non-rectilinear the lens is). But let me explain.

 

What Conrad is saying is that the compression between subject and background has zero to do with focal length, and everything to do with how far away the camera (or observer) is from the subject. Lenses just magnify. Wide angles don't actually 'stretch' the scene, either.

 

Think of it like this: if lenses were the cause of compression, you'd never be able to take a wide shot with a large format camera. You can prove all this with geometry, but I don't know if I can explain it correctly, so I'll let someone else take that on.

 

As for the difference between 35mm and 8x10, yes, there is a massive difference but it's to do with image quality. Side note: notice how people who shoot large format stop right down and get everything in focus, while small many format shooters make a big deal of shooting wide-open? Just a thought.

 

As for movies, the thing there is that 16mm has its own look, as does 65mm. Both are actually very pleasant, which is why you could argue that it doesn't matter which one you choose.

IMO, movies are a complication because you're averaging frames with the persistence of your eye. With a still image sharpness and grain patterns are fixed and easier to evaluate. There's also a general rule that you should view images from a distance about equal to the diagonal. You don't look at a movie from six feet away, nor a billboard. "Pixel-peep" either of those close up and you'll be quite disappointed.

 

To better understand the perspective issue, find a patient dog. Close one eye, yours, not the dog's, and look at the dog from 3 inches in front of his nose. How big is the nose compared to the eyes and ears? Now back up. Size of nose compared to ears? Problem is the whole head is now small. Cure is a longer lens so the head becomes larger in the frame. The perspective doesn't change a bit. The effect is more subtle in portraits, but good looking traditional portraits are usually shot from six or more feet away. IMO, this is one of the problems with cell phone cameras. They tend to be very wide angle so taking a good traditional portrait is difficult. OTOH, after seeing enough close-up wide angle shots, maybe that will become the new norm.

 

Many years ago I took photo courses at RIT. They made us print everything at 11 x 14 inches. The reason was to pound into our heads that 35 mm wasn't good enough for commercial studio type work and only medium and large format could fill the bill. They were right... back then with film. Today full frame digital has come so far as to be good enough for almost anything. Notice I said almost. There are still a few things where you need better, but not often.

 

I want to emphasize again, how are you viewing images? If it's on a computer screen, even a pretty decent one, it's no match for a good print. You won't be able to see certain qualities people talk about, especially concerning large format black and white qualities. Not just basic sharpness, but there are certain edge effects that enhance the image that are pretty much gone on a monitor.

 

Finally, it's still the image that matters. You can make the best technical but craptastic image in the world and it will still be completely forgettable. OTOH, some of the most important and influential images ever taken were taken under difficult conditions and are technically substandard in many ways, but nobody cares because the message is so well delivered.

A lot of good information and clarification. So am I right in saying the lens NEVER distort the image, only the "perspective" does. Like a typical persecutive shot of any building or highway?

2) 50mm lens distort portrait more than 75mm, which in theory is true, but I can't tell the difference by my naked eye.

Let's deal with this one first, since it's fairly straightforward.

 

The 'distortion' being talked about is perspective distortion, not lens distortion.

 

A longer lens allows you to get further from the subject for the same subject-size in the frame, and therefore the perspective is 'flatter' than shooting from a shorter distance.

 

Example: A person with a long, pointy nose (like me) will appear to have an even longer and bigger nose if photographed close up using a wideangle lens; simply because their nose is closer to the camera than the rest of their face. Step back to 2 or 3 metres with a short-telephoto lens, and their nose looks shorter and smaller by comparison. That's a simple example of perspective distortion.

3) Image sharpness varies at different F stop for the same lens.

Definitely true, but you won't see it so much at middle apertures like your f/2.8 ~ f/5.6 examples.

 

Lower cost, or older wide aperture lenses don't perform well wide-open at apertures like f/1.4 or f/2. They generally show lower contrast and less sharpness than the same lens stopped down to f/2.8.

 

At the other end of the aperture scale an effect called 'diffraction' kicks in, and even a perfect lens used at f/16 will definitely look less sharp than at f/4. Diffraction is an unavoidable optical phenomenon and affects all lenses.

 

This is a dot sharp image of a tiny section of a half-toned picture.

 

You can easily see that the definition gets worse as the aperture gets smaller.

4) As well as, beat to death debate of film looks different than digital. ( I'm talking about color graded film stocks used for motion picture specifically)

That's a whole other can of worms to open.

Personally, I see nothing to support that, but then when everything is digitised to show on the web; how can any difference be shown?

 

What really makes me wonder is, why do people shoot film only to digitise it and end up with a digital file?

Edited August 20, 2020 by rodeo_joe|1

I only shoot/view digital photo's with a FF camera and one of 2 zoom lenses ((24 - 70mm, 70- 200mm).

 

My 2cts:

 

Aperture/sharpness

There are t'wo different factors to consider: The first is the optical performance (sharpness) of any zoom lense at different focal lengths and different apertures. Good quality (often expensive) zoom lenses these days have reasonably good sharpness across the range of focal lengths. It used to be said that prime lenses are always sharper than zoom lenses, and the wider the zoom range is, the less sharp photos might be at certain focal lengths (usually the lower and upper limits). Lense technology and quality is improving all the time so I'm not sure if this is still true. In terms of aperture, lenses tend to be (optically) less sharp at the widest and smallest aperture settings. A rule of thumb is that the 'sweet spot' is 2-3 stops down from the widest aperture but this varies per lense. Most lenses are sharp in the centre but some may be less sharp at the edges.

 

The second factor is the Depth of Field (link). Depending on your distance to people and things in the photo frame, your focal length and aperture, a greater or smaller range of people and things in the frame will be in focus (sharp). For landscapes, you might want the depth of field to be as great as possible so that everything is in focus. For portraits, you might choose a shallow depth of field to 'blur the background. The difference between f/2.8 and 5.6 is (for me) not so great. But I can see that the background trees are just slightly more in focus at 5.6. But I'd normally not notice the difference. You might want to experiment with f/2.8, f/8 f/16 and f/22.

 

Focal length and distortion

See this article. Bottom line: focal length (in itself)has not effect on distortion. How you work with it (your distance to the subject in relation to a focal length) does.

 

Film vs Digital

I doubt whether this debate will be over anytime soon. On the one hand, many FF digital cameras now have a sensor resolution that - for practical purposes - is equivalent to film. On the other hand, a digital sensor's response to light is linear and colors are approximated in pixels while film responds chemically and is perhaps more tolerant of highlights and shadows. But ... the dynamic range of digital sensors now often exceeds that of film. Digital post-processing can come very close to simulating a 'film look''.But photos taken with film still have - out of the camera - a quality that digital photos don't. And many people (especially at PN!) just enjoy the process of working with film cameras. There are many side-by-side comparisons on the web, especially on YouTube. Just google Film vs Digital and take your pick.

 

Finally, I entirely agree with @conrad_hoffman in that it's the final image that counts Cameras, lenses, and post-processing software are tools that help you create the photos that you want. Choose the tools that enable you to work well and you feel comfortable using. Of all the factors that determine the quality of photos (however you define this), equipments is IHMO the least important.

P.S.

One more reason for stepping back and using a longer lens for portraits, and one that gets rarely mentioned: You include less background.

 

This can be important for studio shots where the backdrop is limited in size, or also outdoors where you're likely to have an untidy or cluttered background. It's better to have a few out-of-focus leaves behind someone's head, than having an entire tree growing out of it!

Thank you for all your folks' response. It's been educational. My take-home so far has been

 

1) 35mm/medium/large will show resolution difference on large print, but not so much on a computer

2) (Normal) Lens distort distance, hence distorts subjects. e.g fisheye lens trying to squeeze far object closer, hence bending the lines?

3) There is sharpness difference between different f stops. But I still find it true only when you compare two extremes like f5.6 vs f32.

To me it's virtually indistinguishable for less than 3 stops.

And the same goes for film formats, yes, 35mm vs 4x5 you can tell difference in large blowup prints. But 35mm vs 645? Unless we are talking billboards, I don't believe so, unless there's proven blind test with the naked eye..

4) Much the source of my questioning comes from the fact, in my generation( early 20s), everything is viewed from LEDs, so I'm rather unaware of any of the minute details only show on actual prints.

 

And, therefore my new understanding is that, current preference for shooting film lies only in two aspect 1) the work flow, 2) the out of factory color grading. 3) Making large print copies for display. Apart from these aspects, it's rather pointless to shoot film and pretend it's inherently different from digital, while be we are viewing on a LED, whether it's computer, cell phone.

 

Am I mistaken in any of the points mentioned above?

Edited August 20, 2020 by jamietea20

"I'll give my answer here, because it's something that I see often, this myth that lenses 'compress' distances. Even some cinematographers believe it!"

 

I see this so often when someone wants to bring up a mundane technical point. The lens doesn't compress the distance it just makes it look like it compressed the distance.If a cinematographer wants to make it look like the actor is on a crowded city street, he sends the actor up the street and shoots him from a few hundred feet back with a long lens. That doesn't compress anything it just makes it look like all the people on the street are really crowded together.

 

A long lens doesn't compress anything it just makes it look like it compressed it. If you want the look of things being compressed you use a long lens. You can use a short lens and then crop out maybe 5mm from the 35mm film and blow that up and it would look compressed (and very grainy). But, why not use a long lens in the first place to get the compressed look?

But 35mm vs 645? Unless we are talking billboards, I don't believe so

The quality improvement is clearly visible in a 10" x 8" or larger print, assuming the same film and a good-quality lens is used for both formats. Otherwise, why would 645 cameras even exist? And why would people pay more for them and the film to go in them?

 

With faster films (> 400 ISO) you probably don't even need a 10" x 8" enlargement to see the difference.

"I'll give my answer here, because it's something that I see often, this myth that lenses 'compress' distances. Even some cinematographers believe it!"

 

I see this so often when someone wants to bring up a mundane technical point. The lens doesn't compress the distance it just makes it look like it compressed the distance.If a cinematographer wants to make it look like the actor is on a crowded city street, he sends the actor up the street and shoots him from a few hundred feet back with a long lens. That doesn't compress anything it just makes it look like all the people on the street are really crowded together.

 

A long lens doesn't compress anything it just makes it look like it compressed it. If you want the look of things being compressed you use a long lens. You can use a short lens and then crop out maybe 5mm from the 35mm film and blow that up and it would look compressed (and very grainy). But, why not use a long lens in the first place to get the compressed look?

 

"A long lens doesn't compress anything it just makes it look like it compressed it", Well, then why does it "look" that way, isn't it because the long lens "compress" the distance, by bringing far object closer then? Like a binocular.

Well, then why does it "look" that way, isn't it because the long lens "compress" the distance, by bringing far object closer then?

Take a wide-angle shot and then a tele shot from the same position. Now crop the wide-angle shot to show the same frame as the tele shot - what difference do you see (aside from the obvious reduction in resolution)? Absolutely none whatsoever! Distances between foreground, middleground and background are exactly the same. Perspective only changes when you change position - take a tele shot (e.g. portrait) and then move in closer to take the same frame with a wide-angle - now you get the "steep" perspective with a huge nose and tiny ears in the wide-angle shot.

 

But I still find it true only when you compare two extremes like f5.6 vs f32.

To me it's virtually indistinguishable for less than 3 stops.

Differences are definitely measurable and in many cases also visible when examining a print or an image on a computer monitor close enough - sometimes even at normal viewing distances when the lens in question is really poor or has some undesirable characteristic like field curvature.

 

I am not going into the discussion of film vs digital (beaten to death and beyond already) or the differences between 35mm film and medium format - especially not when digital is thrown into the mix. I am with rodeo_joe on this - if there wasn't a benefit in using medium format film cameras, then they would not exist.

Here are two chairs in my backyard taken with a 50mm lens.

 

 

Here are the two chairs taken with a 400 mm lens from much further back. Notice how they look compressed together. Okay, a long lens doesn't compress things it just makes them look as if they are compressed.

 

 

 

But we can get the same look by using a normal lens from the spot where the long lens photo was taken:

 

cropping out a small section from the negative:

 

and then blowing that up in the enlarger. See? It looks the same as the telephoto shot. Why doesn't everybody just use a normal lens and crop what they need from the negative?

 

You know what, I am still going to use a long lens if I want a compressed look. And I bet the cinematographers do also.

Like any topic, the truth lies in the details and conditions of the test, which unfortunately aren't always articulated, leaving those who aren't technically trained to accept or reject at face value. This makes many novices skeptical or lacking the context into which to reach conclusions. To further complicate the issues, the widespread use of the internet and social media to communicate "truths" without verification, often leads to incomplete or inaccurate conclusions. I've found, in training others in a variety of topics, that their depth of understanding is directly proportional to the skill of the teacher & you've had some pretty good "teachers" above giving you guidance. Technical questions are best illuminated with technical explanations.

3) There is sharpness difference between different f stops. But I still find it true only when you compare two extremes like f5.6 vs f32.

Then you're not looking closely enough!

) (Normal) Lens distort distance, hence distorts subjects. e.g fisheye lens trying to squeeze far object closer, hence bending the lines?

You still don't seem to be getting it.

Forget fisheye lenses, they're designed to distort. Most other (rectilinear) lenses aren't.

 

Here's a shot of my poor old garden shed, taken close to using a wideangle lens -

Notice how the near corner appears to have a sharper angle than 90 degrees? It doesn't really. That's perspective distortion from being close to the subject.

 

Here's the same shed from 4 metres away with a longer lens -

The corner looks much squarer now, due to the greater distance, not the lens.

 

Back to the wideangle lens at 4 metres. Cropped to match the 72mm field of view -

And here's the wideangle full-frame with the crop highlighted -

Just in case you thought I was cheating in some way!;)

Edited August 20, 2020 by rodeo_joe|1

"The lights are on, but there's nobody home" - Father Dougal to Father Ted, from "The Passion of St. Tibulus".

Thank you for all your folks' response. It's been educational. My take-home so far has been

 

1) 35mm/medium/large will show resolution difference on large print, but not so much on a computer

2) (Normal) Lens distort distance, hence distorts subjects. e.g fisheye lens trying to squeeze far object closer, hence bending the lines?

3) There is sharpness difference between different f stops. But I still find it true only when you compare two extremes like f5.6 vs f32.

To me it's virtually indistinguishable for less than 3 stops.

And the same goes for film formats, yes, 35mm vs 4x5 you can tell difference in large blowup prints. But 35mm vs 645? Unless we are talking billboards, I don't believe so, unless there's proven blind test with the naked eye..

4) Much the source of my questioning comes from the fact, in my generation( early 20s), everything is viewed from LEDs, so I'm rather unaware of any of the minute details only show on actual prints.

 

And, therefore my new understanding is that, current preference for shooting film lies only in two aspect 1) the work flow, 2) the out of factory color grading. 3) Making large print copies for display. Apart from these aspects, it's rather pointless to shoot film and pretend it's inherently different from digital, while be we are viewing on a LED, whether it's computer, cell phone.

 

Am I mistaken in any of the points mentioned above?

 

I shoot both 35mm film and 645 and I can easily tell the difference even on a computer display (after scanning). I have a largish monitor and I can display what would be close to two or three 8 x 10 portraits side by side. The dye clouds/grain will be pretty evident in the 35mm photos, while practically invisible in the 645.

 

Mixing 35mm and 645 in a slide show on that display, it would be very apparent in most photographs which were shot in which format, - if the picture was up for more than a second or two.

 

Why do you think I bother with 645?

 

Would a casual observer notice the difference? Maybe not, unless I had two photos of the exact same thing right next to each other in the slide show.

 

That's just a computer display. Now imagine a slide show on someone's TV. 40" to 65" TVs are pretty common. 35mm would not look nearly as good.

 

Most of the prints I do are in the form of a photo book I make for my wife on an annual basis. It's an 8 x 10 book and most pages have anywhere from 2 to 4 photos on them. 35mm is just fine for that. Even for an 8 x10. You can see some grain but that's not necessarily bad.

 

If I want a print to put on a wall, it's probably going to be from a medium format or digital camera. But what if I had a really great picture from a 35mm camera? Sure, I might put that on a wall too, - but more for quality of the content than for the quality of the print itself, - if that makes sense.

Edited August 24, 2020 by tomspielman

I shoot both 35mm film and 645 and I can easily tell the difference even on a computer display (after scanning). I have a largish monitor and I can display what would be close to two or three 8 x 10 portraits side by side. The dye clouds/grain will be pretty evident in the 35mm photos, while practically invisible in the 645.

 

Mixing 35mm and 645 in a slide show on that display, it would be very apparent in most photographs which were shot in which format, - if the picture was up for more than a second or two.

 

Why do you think I bother with 645?

 

Would a casual observer notice the difference? Maybe not, unless I had two photos of the exact same thing right next to each other in the slide show.

 

That's just a computer display. Now imagine a slide show on someone's TV. 40" to 65" TVs are pretty common. 35mm would not look nearly as good.

 

Most of the prints I do are in the form of a photo book I make for my wife on an annual basis. It's an 8 x 10 book and most pages have anywhere from 2 to 4 photos on them. 35mm is just fine for that. Even for an 8 x10. You can see some grain but that's not necessarily bad.

 

If I want a print to put on a wall, it's probably going to be from a medium format or digital camera. But what if I had a really great picture from a 35mm camera? Sure, I might put that on a wall too, - but more for quality of the content than for the quality of the print itself, - if that makes sense.

Let me ask you this, have you seen the movie Dark Knight? It was shot on 35mm and 65mm, were you able to tell which one is which when you were looking at a 40 FEET screen in the movie theatre?

Let me ask you this, have you seen the movie Dark Knight? It was shot on 35mm and 65mm, were you able to tell which one is which when you were looking at a 40 FEET screen in the movie theatre?

 

Did not see it in the theater I'm afraid. Let me ask you a question. Would iMAX movies look as good if they were shot on 35mm?

 

Anyway, you're comparing movies viewed from a long distance away to stills being viewed from within a few feet. Very different things.

 

A typical movie theater screen is anywhere from 45 to 65 feet wide. Let's assume for simplicity that the screen is 50 feet wide. The average distance from the screen in a movie theater is about 1.5 times the width of screen. So in this case people are sitting an average of 75 feet away.

 

How far away are you from your computer monitor when you're looking at a pic or how far away do you usually stand from a 16 x 20 print mounted on a wall?

 

Plus in movies the frames are moving by at 24 or 48 frames per second, - which hides the flaws you would notice in a still.

 

You don't have to believe me. It sounds like you have access to both 35mm and medium format cameras. Shoot a roll of the same type of film in both and have decent scans or largish prints made. You'll see the difference.

1) 35mm/medium/large will show resolution difference on large print, but not so much on a computer

paraphrase that to "to see something I need at least a 4K screen"

35mm vs 4x5 you can tell difference in large blowup prints. But 35mm vs 645? Unless we are talking billboards, I don't believe so, unless there's proven blind test with the naked eye..

suggestion: Load Ilford Delta 3200 or your yery Plain Jane ISO 400 BW stuff (something worse than HP5) of choice, print 8x10". 35mm should be quite horribly grainy, 645 kind of bearable.

Sure, you have to print bigger to see the same on less crappy film but on the other hand it gets you nowhere to risk camera shake combined with "almost in focus", just to get rid of grain.

I guess I agree to the fact that there IS a difference but what I'm trying to say is that they are so minute that in most of the circumstances, (especially when today everything ends up to be viewed on a computer), it is almost pointless to spend the extra bucks.

If, at the end of the day, your work ends up on instagram.....

Edited August 31, 2020 by William Michael

Yep, I would agree with that. I don't use my Fujica GS645 a lot, but it's got a sharp lens, I often have film in it, and it's more portable than most 35mm SLRs. So if I'm going somewhere where I think I might get a shot worthy of putting on a wall, I'll take it along.

 

The portability is one reason I sold my TLR and got the Fujica. Some people are happy just carrying the TLR around. I'm not. Too bulky. That said, I got some really nice pictures with it, but they were always planned.

Edited August 31, 2020 by William Michael

Most of what I do ends up on the 'net but I still like to get better quality than what's necessary for that. As an example, say I shoot a product for my employer, who puts it on the web site. Great. Then they say, "Oh, that looks good, lets make a 6' wide print for a show booth." Or, maybe I shoot some family stuff that goes on Facebook. Everybody likes it and then somebody asks for an 11 x 14 print. You can always reduce quality but it's near impossible to increase it.