Benjamin Dietze

And that's exactly where you were wrong, and still are wrong. Why did I start talking about "normal" lenses, after all? Because a "normal" lens is defined by the field of vision it gives you in combination with the format you're using. I literally said that a "normal" lens in 16mm or 35mm will be a telephoto lens in Super8. That's where you were butting in and said, "Oh, it doesn't matter, because focal length is always the same, so a 'normal' lens will always be 'normal' ", and that was because a.) you didn't know we're talking about going from one format to another, which was because of b.) that you had no idea what field of vision and the format factor are. That was muuuuuuch later after you've already "corrected" me again and again because you had no idea about format factor, field of vision, perspective, focal plane, or many other optics topics. But hey, that's okay! I know little about loss of light and logarithms. But I don't go and claim I do and blame everybody who doesn't agree with my hijinks I come up with because I have no idea about it. And what I was referring to there is the fact that most focal length-field of vision conversion tables are exclusively geared towards 35mm, and it's the only figures most people know about. They "know" that 50mm "is a normal lens", they "know" that 28mm "is a wide lens", and that 18mm "has a field of vision of 100°". They still "know" this if they know anything about focal length, even though they're using way other formats. And why do they "know" all this? Why are those the only tables you only ever come about? Because for most of the 20th century, 35mm was the dominant movie and still photography format in the world, especially in the professional fields where people actually cared about field of vision. That's why people rather buy a new lens, or even new cameras, than having to do the math. Because there's hardly any conversion tables around for any other formats beside 35mm. And it shoulda been obvious for you after everything I'd already told you again and again about the format factor by then. Not once you go and take the same lens and use it on two different formats. See http://en.wikipedia.org/wiki/Crop_factor Which it was we've been talking about all the time, even before Carl came in and claimed that a "normal" lens will always be a "normal" lens, no matter what format we're using it for.

Or gave patently false definitions on both perspective as well as field of vision.

Carl, Erkan didn't say that you were the one who was right in the discussion. Others didn't give names but called our debate a lesson given to a total newb about optics and the format factor. It's not me who couldn't tell field of vision from perspective, perspective from light circle, and light circle from the crop factor due to imaging area size, or had no idea that you can't change the lens-to-imaging-area distance infinitely and still expect to be able to get anything remotely resembling focus.

My old reason is identical to the new reason. I want an angle of vision of 100° or more in every format, and I don't wanna pay a huge amount of money I don't have because of an unfortunate mount choice, nor do an insane amount of math. It's you who I had to explain to for hours what the format factor is. First you thought that a number printed on the outside of the lens (i. e. the focal length) would magically change because you had no idea what the field of vision is. Then you didn't realize that we're talking different formats here, because most C-mount lenses were made for much larger formats, and what a different format does to the field of vision. Then you kept confusing field of vision with perspective. Then you kept confusing field of vision with the light circle. When all this time, I've been talking about the fact that field of vision changes with format, and that what I want has nothing to do with the light circle (and, just to be sure, little with "a wide aspect ratio", such as that of UltraPan8, for that matter, although it may be easier to come by the right lenses there). It has to do with extremely converging lines because of a field of vision of 100° or higher on a rectilinear lens.

One or two small French/Spanish companies recently tried to re-introduce pre-striped S8 carts. But they never got beyond proof of concept/test films, then they decided that the demand was too low. As for the old stocks, Kodak stopped selling pre-striped E160T in 1997 or 1998, so that's the newest batches you can get. As for post-striping after processing, there's a few magnetic-striper devices at the size of cigar boxes to be found on eBay at times. Problem is finding magnetic stripes in the right format. In any case, sound is another problem neatly solved by Lasse's upcoming new camera.

Wow. It's expensive for my lens budget, but gee! Those specs sure make my mouth water.

Exactly. Thank you for once again repeating to me what I've been trying to explain to you for hours, and then act as if I was the one who's not getting something. That's why I said you'd have to give two figures: Angle of vision and format. In short: I'd much rather go with a manual that had a table stating the field of vision for every format than with a single focal length figure. And thank you, Carl, for demonstrating why most people look for other lenses that do give figures for the format they wanna use it on, rather than do half an hour of math because all the figures given for a lens are speed, aperture, and focal length. In all of my educations, not even any of my educators could do the math, including those that were running their own production companies. Whenever I asked them, they all recommended me to use a lens exclusively for the format it was made for. It was easier for them to buy a new lens rather than try and do the math. And I'm sorry that I didn't know about UltraPan8 (and for skipping over the one sentence where you mentioned the film format you're using, because all the math scared me off), although I do know about R8 and DS8. I haven't looked into those formats for active shooting during the past 15 years though because of the lose reels (I'm very clumsy) and the supply situation, i. e. the number of stocks available readily out of the box in comparison to S8, rather than custom-made batches that are most likely either pricey or re-cans, or both. I've been telecining lots of R8 though. There are so many people tinkering with their camera in their backyard and call it a new format. Currently, there's a guy in Switzerland who's trying to adapt his Bolex to expose 35mm Academy at the full width, but only the height of a R8 frame for an insanely wide aspect ratio...and then he intends to use it to non-anamorphically (i. e. with huge pillarboxes) photograph his DVDs of 4:3 Charlie Chaplin silent movies off a computer monitor and project them on a custom-made projector. He'll try to maintain lip-synch with some early 4:3 talkies by means of some continually cranked hand-crank that's changing in color once the sound is more than two or three frames off. When he found out there's too little demand for his new format to turn it into a profitable business, he's decided for himself that film is a dead format. When he was pointed to Lasse's new camera prototype, he replied that it's a hobby horse folly that'll never sell as proven by the fact there's not enough demand for his new format.

So Carl, let's rehash what we're going on about. I started talking about lenses and focal lengths because angle of view is *NEVER* the same once you change the format, because I want an angle of vision of 100° or higher in every format, and most C-moutn lenses were made for much larger formats than Super8. Ever since then, you have been trying to tell me that angle of vision always stays the same as long as you're staying within the same format. Once I've made you understand that we're talking about the format factor here because most of the lenses were made for different formats, you're trying to tell me I'm confusing angle of vision with light circle, before going on about angle of vision staying the same within the same format again. And you're trying to tell me that I've got something wrong here? And welcome back, Lasse. Have you seen the very low-priced mount options with P + S that somebody posted here? They'd custom-make your mounts for a price that will be pretty low for us as the end customers down the line as long as you'll have a series (say, 10?) of cameras made with each mount, and some customers may even ask for a multi-mount camera where we'd only have to use a screwdriver to switch the front plate or something, and replace it with the other one(s) from the set.

Also, thanks for your Vimeo link, but I'm not seeing the extremely converging lines that I'm after with an extremely wide field of vision. Obviously, you didn't use a focal length that woulda given a field of vision of 100° or higher in UltraPan8.

Yes, which is why I said that with Super8, the lens circle issue is usually neglectable as Super8 is so small compared to most other formats, although many manuals and FAQs caveat that the light circle for a given lens may "not be usable for film" because they're simply thinking in terms of the large 35mm format. I said that while maintaining that it's hard to go beyond a field of vision of 100° in Super8 because I do know the difference between field of vision and the light circle. That's why I said that it would be much more economical to switch to CS-mount because those lenses were usually designed for smaller image areas such as 1/3", so it's easier to come by a lens with a wide field of vision in Super8. Yes, but there's just no physically possible way to move a tiny Super8 imaging area far enough to achieve a field of vision or crop even remotely equaling that of 16mm or even 35mm without moving it waaaaay out of the focal plane so badly that no amount of focussing range could ever help getting the image in focus again. The only workaround to that are very, very expensive adapter lenses that are usually called 35mm adapters (such as those that happen to be made by aforementioned P + S, although at far higher prices than the ones for just a set of different mounts), although most videots only use it for a "filmic" DOF (because, as Erkan mentions, smaller formats have larger DOFs) as they have no idea about field of vision. You are wrong in assuming that I would be confusing image circle and angle of vision (as otherwise I wouldn't have said that the commonly related light circle issue doesn't matter in Super8 while maintaining that it's harder to go *REALLY WIDE* with Super8). I have been talking about field of vision all the time, and only once mentioned the light circle in passing, saying that we don't need to worry about it in any way because Super8 is so small, whereas I said that we *DO* need to worry about field of vision and focal length.

(Still replying here as I don't see any new thread devoted to this issue.) Weird. The images showed up for me in my final post on Tuesday, but now they don't. So here's their original Wikipedia URLs: http://upload.wikimedia.org/wikipedia/commons/9/98/Format_Factor.gif http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Full-frame_vs_APS-C.svg/595px-Full-frame_vs_APS-C.svg.png http://upload.wikimedia.org/wikipedia/commons/4/49/LensCropFactor.png Anyway, here's one of the two promised sources I had on the C-vs.-CS-mount dispute: So because according to www.c-mountlens.com, C-mount lenses protude more than CS-mount lenses by 5mm, you'll need a 5mm extension ring in order to use a C-mount lens on a CS-mounted camera, but not in order to put a CS-mount lens on a C-mounted camera where the only problem will be that the lens is macro. The other source that agreed with www.c-mountlens.com that C-mount lenses protrude more than CS-mount lenses, complete with schematic graphics, was at http://www.scansourcesecurity.com/MicroSites/ScanSourceSecurity/ipcenter/files/CameraandLensCompatibility.pdf , but it appears to have been deleted over the weekend. Perspective does not equal angle of vision. Perspective refers to the mathematical phenomenon or behavior of lines leadings towards one or several vanishing points, whereas angle of vision refers to "how much you see", in other words, where the cut-off edges of your image are and what's squeezed in-between them. Exactly. That's why it's called format factor, and why I said that the angle of vision for a given lens for one format (such as 35mm) does not equal the angle of vision with the same lens, but a smaller format (such as Super8). In other words: You need insanely costly C-mount lenses to achieve a rectilinear field of vision of 100° or above in Super8. No. See the respective definitions of perspective and field of vision above. Once you lose stuff on the edges, it's called cropping. Which is why the format factor is also known as the crop factor. Perspective is a real thing, albeit one that does not equal field of vision (see above). The illusion is such that people erroneously perceive a dizzying change or rather distortion of perspective because the human brain processes converging lines on a 2D image as representations of size and distance. As soon as you've got a rectilinear lens with a field of vision that's larger than the human one, angles will change in such a way that the human brain automatically perceives things as grotesquely and imposingly larger than they usually appear with a human field of vision because of the change in converging lines, especially the closer to the lens a photographed object is. That's why wide-angle lenses enlarge the perspective perceived by a human audience (whereas telephoto lenses compress it, an effect used by Leni Riefenstahl in Triumph of Will in order to compress large crowds and juxtaposing those compressing telephoto shots with shots of their Führer seen through normal lenses instead to make him appear tall and allmighty in comparison), a wide-angle effect that you can emphasize by putting important objects closer to the lens than others, even though its wide field of vision will paradoxically capture more background around the object. Once you go from wide-angle to rectilinear ultra-wide angle, the effect becomes so great that it begins to arouse vague feelings of confusion, disturbance, unsettling, bizarreness, or even enchanted whimsicality, grandness, and majesty, depending upon other factors such as lighting, production design, mise-en-scene, and plot. Which is part of the reason why I've said in a post somewhere here that it would be much more intuitive to give the field of vision for a given lens on a variety of formats, rather than sticking to focal length figures usually derived from 35mm Academy or 35mm Full-Format. Yes, I'm sorry for my rude wording. In any case, prior to my last post, you kept saying that we don't need to worry about achieving any field of vision with any given lens in Super8, because you said that "all lenses always have the same field of vision, no matter in what format". We were not comparing Super8 with Super8, we were comparing focal lengths and the field of vision of given lenses in 35mm and 16mm with Super8, so format and crop do change. The answer is close, but no cigar. We were talking about whether a 7mm lens will have the same angle of vision in Super8 as it does in 16mm and 35mm. That's why the answer is no.

That's a really sore issue. You can only be sure if they exactly state what format the focal length and field of vision figures relate to. As far as I can tell, UltraPan8 is Max8 with an anamorphic lens, right? The problem here is that anamorphic lenses are in a way higher price range as well.

Think of it like this: The smaller your format (blue rectangle), the more it crops from the sides of the image you woulda gotten with a larger format (red rectangle) at the same focal length. Which is why it's stupid to stick to focal length figures for 35mm in an age where most formats we have indeed have little to do with the dimensions of 35mm Full-Frame or 35mm Academy, even in consumer still photography. What would be much more intuitive would be giving a lense's field of vision for any given format size. Percentage of image area of 35mm = Percentage of field of vision you'd have with 35mm (I think).

And this was supposed to be wider, of course!

That, BTW, goes for the size-decreased side of the lens. It's different for the size-enlarged side, which is why projector-screen distance is much more variable.