Why Bigger is Better (but not much else) S35mm vs. Vistavision Comparison

[Hrvoje Simic]

Hrovje's example posted above is on an APS-C sensor for both images. If I remember correctly, one is a 35mm, the other is a 50mm + a speedbooster.

Which means the sensor size is a fixed variable and therefore it's out of the equation entirely. It became a direct comparison of two different optical systems. Which means this whole argument comes down to optical design.

H-R-V-O-J-E

Yes, the whole argument is in optical design of a lens with its focal length.

"No no it is not focal length, it is nodal point"
"No no it is not focal length, it is the speedbooster".

It is not the speedbooster. Speedbooster is irrelevant.
You are watching the geometric effect of two different formats with equivalent FL for AOV.

 

[Björn Benckert]

H-R-V-O-J-E

Yes, the whole argument is in optical design of a lens with its focal length.

"No no it is not focal length, it is nodal point"
"No no it is not focal length, it is the speedbooster".

It is not the speedbooster. Speedbooster is irrelevant.
You are watching the geometric effect of two different formats with equivalent FL for AOV.

H-R-V-O-J-E, If you add a speed boaster you simply shorten your focal length and decreased your image circle. So the angle of view is not the same and the FL is not the same on the lens after you add a booster.

The difference between a 35mm and 50mm with a speed booster.. ( i dont know the strength of the booster) but lets pretend it made the lens into a 35mm. Then the difference you would see is not the difference between two formats. What you see is the difference between a 35mm lens and a 50mm lens converted into a 35mm with one extra element. Speed boosters are usually not optimal way to make a lens, they are not adapted specifically to one focal length or lens so the distortion with a speedboater can vary quite a bit.

 

[Hrvoje Simic]

H-R-V-O-J-E, If you add a speed boaster you simply shorten your focal length and decreased your image circle. So the angle of view is not the same and the FL is not the same on the lens after you add a booster.

Glad we started to pay attention on spelling people's names when addressing them.

So...what would you say would be the focal length of the lens and its AOV...of that 50 mm lens shot in my test which gives same (similar) AOV as 35 on APS-C but with differing geometry ?

 

[Björn Benckert]

Glad we started to pay attention on spelling people's names when addressing them.

So...what would you say would be the focal length of the lens and its AOV on that 50 mm lens shot in my test ?

If you shot with a 50mm lens with a ASP-c sensor your AoV is 26.6° in horisontal.

What your booster added I dont know as I dont know how strong it was, if it was bosting 0.3 it would make your 50mm into a 35mm. But most likely your nodal point is moved forward and most likely you got a pretty shitty lens, distortion vice.

Adding a speedbooster to a 50mm is not really best practice to create a good 35mm lens.

 

[Tobi Rupp]

Hi everybody,

interesting topic and conversation.

Beside all the pro and cons about large format photography, speaking about RED Monstro VV the fact alone how the new Monstro Sensor is performing in every way is a huge
step forward and worth to go this route.....

 

[Björn Benckert]

Hi everybody,

interesting topic and conversation.

Beside all the pro and cons about large format photography, speaking about RED Monstro VV the fact alone how the new Monstro Sensor is performing in every way is a huge
step forward and worth to go this route.....

Agree, not only is it large format but it´also the its absolute best s35 sensor I ever tested.

 

[Ron Steinberg]

I'm amazed that you are more intimately involved with the top image -- they look almost identical to me, but even seeing some differences in optical distortion across the field, I'd be hard-pressed to find any emotional difference being evoked.

I think I'm just responding negatively to the marketing pitch for larger formats going on, which is a bit too pseudo-sciency for my tastes. I'd rather they stick to the facts, or tell people that there are some cool larger format optics that they can play with now rather than imply that now their wide-angle shots will "feel" like telephoto shots but with a wide-angle view.

I understand what you mean David - and of course there isn't any emotion being evoked by looking at a simple desk shot. What I mean is the relationship in distance between the keys in the foreground, the Enterprise in mid field, and the two glasses in the background. Imagine these are actors. The spatial relationship between these three points is different between the two frames, and in the top one (the 50mm?) they appear closer to each other to me, while in the bottom frame, there is more distance between them, the space between them is stretched out. So I feel that there is a more intimate connection between these three elements in the top frame. It's subtle but it's there in my observation. But if I hadn't been able to go back and forth between the two frames? I'd never know the difference.

My experience is two decades of shooting commercial advertising photography, mainly on 4x5 and 8x10 transparency, and all the way down to 35mm stills, and finally transitioning to full format 35mm digital before exciting the industry. I don't for the most part enjoy large format as it's being used in cinema today, for super shallow depth of field. When I see Star Wars and the 1st AC is pulling focus between two pilots in the Millenium Falcon because they can't get both of them in focus at the same time - that's just annoying and distracting and doesn't fit the Star Wars aesthetic as far as I remember it from a 10 year old kid watching for the first time in '77. I feel we've gone over the deep end with the shallow depth of field and large formats are just enabling it. It's a gimmick, not more filmic. Is Citizen Kane less filmic because of the deep focus techniques used? Enough of my rant, I'll let everyone get back to arguing over sensor sizes.

 

[Björn Benckert]

I understand what you mean David - and of course there isn't any emotion being evoked by looking at a simple desk shot. What I mean is the relationship in distance between the keys in the foreground, the Enterprise in mid field, and the two glasses in the background. Imagine these are actors. The spatial relationship between these three points is different between the two frames, and in the top one (the 50mm?) they appear closer to each other to me, while in the bottom frame, there is more distance between them, the space between them is stretched out. So I feel that there is a more intimate connection between these three elements in the top frame. It's subtle but it's there in my observation. But if I hadn't been able to go back and forth between the two frames? I'd never know the difference.

My experience is two decades of shooting commercial advertising photography, mainly on 4x5 and 8x10 transparency, and all the way down to 35mm stills, and finally transitioning to full format 35mm digital before exciting the industry. I don't for the most part enjoy large format as it's being used in cinema today, for super shallow depth of field. When I see Star Wars and the 1st AC is pulling focus between two pilots in the Millenium Falcon because they can't get both of them in focus at the same time - that's just annoying and distracting and doesn't fit the Star Wars aesthetic as far as I remember it from a 10 year old kid watching for the first time in '77. I feel we've gone over the deep end with the shallow depth of field and large formats are just enabling it. It's a gimmick, not more filmic. Is Citizen Kane less filmic because of the deep focus techniques used? Enough of my rant, I'll let everyone get back to arguing over sensor sizes.

What? when I pull a difference matte between the two frames you see there is zero difference. between the two, or the difference from the change of of optical setup is less than mullens ability to line up the camera correctly.

 

[David Mullen ASC]

Maybe someone should do a similar test but on the same format, but just three lenses of the same focal length made by different manufacturers and see if there are similar differences in compression, distortion, etc.

 

[Misha Engel]

Lets hope that some day someone who can get his hands on a monstro, helium and a Zeiss Cinema Zoom 70..200 T2.9(F2.8) image circle 46.3 mm can test this.
When this would be the perfect lens (which it's not) the conclusion would be that you can match the FOV, DOV,equivalent aperture when physically possible.

With the end conclusion that the Monsto sensor is even better then the Helium sensor and that you can match them with the right optics.

 

[Jon Dishler]

For a zoom, I agree that a larger sensor is great, why I like full frame still photography better than cropped sensor since a 70-200 zoom gives great subject isolation at F2.8. But for lenses that go to F1.4 there is an advantage, as has been mentioned multiple times, that the same perspective, and all other factors can be achieved with the same subject separation using a faster lens set 1.5 stops lower. The benefit is that less light is needed to achieve the same result (which can be bad and require filtering outdoors). The limiting factor in the past has been that smaller sensors have either less photosites, or more noise due to smaller photosites. In the case of Helium, it might not be quite up to Monstro, but has amazingly good small photosites, and just as many of them. In addition, Helium is somewhere in between super 35 and full frame, so the differences between it and Monstro are less than what is being discussed (field of view 73% according to PHFX tools compare). Yes, at ISO 2000 Monstro is definitely better, but how about at ISO 640 and not starving the sensor for light (new calibration for both)? Much easier to achieve at F1.4.

This whole argument about sensor size is sort of silly to me as an Ophthalmologist, because I know of a sensor even better than the Monstro, and it is talked about in the video above by Panavision (https://vimeo.com/248235757). The human eye. They got some of the physiologic optics wrong, but the business end of the eye's sensor is only about 1.5 mm across with the total sensor being only 5 mm. We humans have some tricks in visual processing that gives us amazing vision, but we do it in a very small camera with a tiny sensor. Also having two of them doesn't hurt. And when I work on eyes to change the focus, it is usually on a diameter of about 6-7 mm, that is the size of the effective optics considerations needed for clear focus.

 

[Sidney L. Plaut]

Check altered carbon on netflix on large oled or 4k projector with Dolby vision. Then the alexa 65 really sings, like mad. Sure the HDR stuff adds to the feel (personally I dont really like it, it´s a bit over done feels harsh on the eyes) But I got a alexa project in my box at the moment and was flipping from that to netflix altered carbon on the same oled screen. And the difference is quite massive. Sure different lenses and all that but still. To me it very much have the quality increase that 65mm film has compared to 35mm film. You just need the right monitor to see it. And sadly I dont think the movie theatres have it and/or usually post has dipped into 2k before making a 4k master and that shows.

Bjørn - If the same camera shoots 6k S35mm and 6k - 65mm. Same dynamic range. same everything - Except Sensor size.

- Then besides having slower panning speeds on the 65mm, what is the "uniqueness" on the 65mm digital - that CANNOT be achieved by matching lenses and T-stop on the S35mm digital?

 

[Björn Benckert]

Bjørn - If the same camera shoots 6k S35mm and 6k - 65mm. Same dynamic range. same everything - Except Sensor size.

- Then besides having slower panning speeds on the 65mm, what is the "uniqueness" on the 65mm digital - that CANNOT be achieved by matching lenses and T-stop on the S35mm digital?

Not sure I understand the question.

You dont need slower paning speed on the 65mm, panning speed is related to field of view not sensor size. Wide and you can pan faster in degrees, allow for more shake, etc.

 

[Aaron Lochert]

Maybe someone should do a similar test but on the same format, but just three lenses of the same focal length made by different manufacturers and see if there are similar differences in compression, distortion, etc.

I actually did just that the last time this was brought up: http://www.reduser.net/forum/showth...-Perspective&p=1784412&viewfull=1#post1784412

All 8K Helium. Right click, open each in a new tab so you can A/B them:

I can show as much 3D/special/perspective/geometry discrepancy between three lenses on the same format.

The next test would be to see if I can get all these to match within a reasonable margin of error by moving the camera forward/back a few inches to line up all their entrance pupil/no-parallax points.

Then, the third test would be to do the exact same thing between 8K with a 50mm and 4K on a 25mm, first, showing that both can have discrepancies when the camera position is locked, and then seeing if both can be matched by aligning the no-parallax points. Maybe I'll get around to that tonight.

 

[Mark K.]

I can show as much 3D/special/perspective/geometry discrepancy between three lenses on the same format.

The next test would be to see if I can get all these to match within a reasonable margin of error by moving the camera forward/back a few inches to line up all their entrance pupil/no-parallax points.

Then, the third test would be to do the exact same thing between 8K with a 50mm and 4K on a 25mm, first, showing that both can have discrepancies when the camera position is locked, and then seeing if both can be matched by aligning the no-parallax points. Maybe I'll get around to that tonight.

Those would be great to see Aaron, do post them if you run the test.

 

[Aaron Lochert]

Alright, I went ahead tested my theories myself.

Here's some 2K versions of the test images. Open these up in multiple tabs and follow along so you can A/B them on top of one another: Shot A, Shot B, Shot C, Shot D.

TEST ONE - LENS VS LENS

In this test, everything is kept a constant except one thing, the lens. These are both 35mm focal lengths at f/8 on Epic-W captured at 8K, 6:1 compression and ISO 1000. Shot A is a Prime, shot B is a Zoom set to 35mm. The camera did not move between the two shots. Shot B was scaled up just slightly to compensate for a larger FoV (for whatever reason) and repositioned so that when A/B-ing between the two shots, we're only concerned with the apparent shift in perspective that happens. As we know, scaling and cropping an image up is not doing anything to the geometry of the scene, so this is fine for demonstration.

This is essentially a recreation of the other test posted before.

You'll also notice the computer tower on the floor tucks under the desk in B and the image is overall more "stretched" spatially - the back row of pawns get smaller as the front row grow larger.

So, this concludes that even two lenses of the same focal length on the same format size can show discrepancies just as large as the ones we're seeing with these multi-format comparisons. So which of these two is the definitive "look" of this format? One is going to make a face look flatter, and the other is going to make a face look more 3D. Those are both tools we can use in our work, but neither one is an indelible characteristic of the format.

TEST TWO - LENS VS LENS w/ REPOSITIONING

We're going to use Shot A as our baseline, so refer to it above.

Now we bring in Shot C.

Shot C's setup is identical in every way to Shot B, the only change is that the camera was pulled back exactly 1" on a set of rails. From my preliminary testing I did with these two 35mm lenses, it seemed that a 1" was the magic number to match the two. I tested many distances in half inch increments and found that pulling back 1" gave the closest match. Could I have gotten it closer? Yeah, probably. But I didn't test smaller increments, nor did I do what I should have actually done, which would have been to locate the no-parallax point directly for each lens and do the math between them. Either way, 1" is pretty close.

So, pulling the camera back on a set of rails ensured the only camera position change occurred along that Z-axis and not X or Y, which would have added lateral/vertical parallax shift. Like Shot B, Shot C was scaled up to compensate for FoV differences so we can look directly at perspective shift and not be concerned with irrelevant (for the sake of this argument) details.

Comparing Shot A to C, what you'll find is that there are still discrepancies that exist, but minimized quite a bit to what we saw in Shot B against A. The interesting thing to note here is that Shot B had the computer tower in the background tucked under the desk more than A. But now, the computer tower emerged from under the desk more so than A. So by pulling the camera back 1", we've gone the other direction with the perspective shifting. The real number must actually be slightly less than 1".

So what does mean? This means we can use this knowledge when we compare multiple formats, because inevitably we'll have to use two different lenses to keep an equal FoV between shots, because that's what matters to us as cinematographers. As we already know, if we kept the same lens on both formats, we'd have two images with wildly different FoV's and zero perspective shift. Which brings us to...

TEST THREE - FORMAT VS FORMAT

Here's the meat of this test. This is what we're all dying to know.

Again, we'll use Shot A as our baseline. Just to refresh your memory, it's an 8K shot on a 35mm lens at f/8 and ISO 1000.

Enter Shot D, which is the same as Shot C (including -1" camera position), but the lens was zoomed out to 17mm and set to f/4. Nodal points can change as lenses zoom out, but luckily for this test, the lens I'm using's nodal point doesn't shift substantially across the zoom range according to a database I found, so our previous 1" compensation still can apply. The camera was set to ISO 250, 4K and 2:1 compression. Since 4K is an exact 2X crop of 8K, this makes our math easy, and we're in the right ballpark for all these settings. As like the others, Shot D was scaled up and positioned to align with the image we got out of Shot A. No other distortion correction or spatial corrections were applied. The color was slightly different due to aperture changes, so that was compensated for (though it's still a bit off) and a touch of sharpening was added since this 4K image isn't seeing the huge benefits of 8K supersampling.

So comparing our baseline Shot A against Shot D, we can see that these two images are far closer in 3D representation than A versus B, minus some barrel distortion. And those were both the same, larger format shots. This is a 2x crop of that. Monstro to Helium is 1.37x, Alexa LF to Alexa is 1.3x, Alexa LF to Helium is 1.23x. And Sony Venice to Helium is 1.2x.

While we're at it, let's look at C versus D. This is also an 8K comparison against 4K. This time it's the same zoom lens against itself in the same physical position in 3D space. D is a bit bubblier looking due to some wavy distortion. Again, still discrepancies, but the front element was 12" away from the front row of chess pieces. We're so close we're amplifying our errors in testing at this point.

So that's it. If I can show two 35mm lenses on the same format looking so different, and then show S35+ against S16+ that look closer matched than the two S35+ shots, then I don't know what I'm supposed to be looking for.

All it took for my example was moving the camera 1" back in z-space to get the no-parallax points to line up. So if that's the difference between making or breaking the "look", then good luck getting repeatable takes within an 1" margin. Your actors will screw that up for you in no time, as will your Steadicam ops and dolly grips. Of course, I'm being facetious; we all know that filmmaking is a lot more of an organic process than that. So whatever.

Don't get me wrong, there's clearly other advantages to large format. I just can't swallow this pill about "natural" perspective, whatever that means. One thread it means things look more stretched out, "rounder" and 3D, another thread it means that things look naturally compressed and less distorted.

¯\_(ツ)_/¯

 

[Michael Tiemann]

Hear! hear! As I said much earlier in this thread, when using 3D software designed to drop a model into a live-action shot, there are typically camera parameters for specifying the virtual image size (such as 24mm x 36mm) and virtual lens size (such as 50mm), but there is NO pixel difference between a 5mm lens casting rays on a 2.4mm x 3.6mm virtual image plane and a 500mm lens casting rays on a 240mm x 360mm virtual image. If there were a meaningful difference in real life, surely the crazy-about-accuracy 3D community would have characterized that and implemented it so that one could achieve "dreamy ultra-large format images" or "edgy small-format images". But that doesn't happen.

They do have ways of simulating bokeh by merging tens or hundreds or thousands of samples of images that represent the multitude of possible ray paths that simultaneously sum (in the analog realm) into bokeh. And if one does the math correctly on circles of confusion, the relative virtual sensor resolutions of the two systems, and the final display format and viewing distance, one can derive that a larger sized sensor gives a shallower depth of field than a smaller sized sensor. But nowhere I have seen that anything other than depth of field/circle of confusion and diffraction limits change with image size and pixel dimensions.

I'll offer this random theory as to why larger imaging systems end up closer to the talent and therefore give more "flattering" results: generations of naive testers have ignored the facts of nodal points, and instead satisfy themselves with sensor-to-actor tape measurements. This has built up the "knowledge" that larger format lenses create better separation of actor and scenery, not because it's true, but because the more forward nodal point of the system does change the perspective in very characteristic ways. If small-format shooters pushed the nodal points of their lenses in as far as the big boys do (out of necessity), they would see the same (pleasing?) perspective distortions.

 

[Misha Engel]

Alright, I went ahead tested my theories myself.


Don't get me wrong, there's clearly other advantages to large format. I just can't swallow this pill about "natural" perspective, whatever that means. One thread it means things look more stretched out, "rounder" and 3D, another thread it means that things look naturally compressed and less distorted.

¯\_(ツ)_/¯

+1 Myth busted (again).

 

[Hrvoje Simic]

+1 Myth busted (again).

What you are referring to neither is a myth, neither anything posted here makes it "busted".

 

[Misha Engel]

What you are referring to neither is a myth, neither anything posted here makes it "busted".

Religion will always be stronger than science...