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Old July 12th, 2006, 10:08 AM   #1
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Canon EEa Screen Static Adaptor: Pix

Much covert lurking on this forum and experimentation later, Adaptor 0.9 finally works! As far as I know, the combination of optics and GGs used in this compact static adaptor haven't previously been tried - it's a combination of Leica, Zeiss and Canon optics.

My background is in stills (I test lenses for fun: http://www.16-9.net/lens_tests ), so bought a slightly different perspective to things. The basic design is similar to a Nikon D Screen model, but the quality is better. Why you guys are still using 50mm lenses for this game, I'll never know . . .

I'm building some web pages comparing HD stills shot without an adaptor, and with two different kinds of static screens. I'll be shooting some test footage soon, but meantime, here are some stills . . . I'd appreciate any feedback and help in resolving a few outstanding problems.

Thanks a bunch for your collective help and inspiration!
http://www.16-9.net/still1.jpg
http://www.16-9.net/still2.jpg
http://www.16-9.net/still3.jpg

Video coming soon . . .

Last edited by Mark Welsh; July 13th, 2006 at 05:22 AM.
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Old July 12th, 2006, 10:19 AM   #2
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Mark, good start, and nice pics. The colors are good, and I do like the bokeh as shown in the flowers picture. I am noticing some edge blur, is that one of the problems you are talking about?

I’d be interested in knowing a little more about the lenses you used and obviously your adapter. Would you mind telling us a little more?
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Old July 12th, 2006, 10:31 AM   #3
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Yes - that's the main problem. There is a little grain, but it's tolerable I think - and the best I've seen for a static adaptor (which, incidentally, was covered with specks).

I'm only using a Sony HC3, and the problem seems to derive from the fact that, although the camera focuses to 1cm, it leaves the corners unsharp. The problem only became apparent when I'd mounted the adaptor perfectly perpendicular.

It's worse without the Leica 4D close up lens I've used on these test shots, but I'm wondering whether a stronger achromat would help. The lovely bokeh is courtesy of the Canon focusing screen and fast Zeiss glass, which seem to combine better than the Nikon D / FD versions.
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Old July 12th, 2006, 11:05 AM   #4
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I have seen the same edge blur in a clip showing how close the HC1 could focus. Is your close up lens a single element? (or rather are close up lenses always single elements) I am by no means an expert in optics, but my understanding is that a close up lens is often a single element which sometimes introduces edge abberation where there was none (or apparently corrects it to a certain extent when there is some from what you say). Now if an achromat (double element) does not introduce (or correct) anything at close range, I’m thinking it would not help at all. But hey, I could be totally off.
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Old July 12th, 2006, 11:18 AM   #5
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Further testing, with and without the adaptor, confirms that the problem is the macro facility of the inbuilt lens - for which there is no cure. It's always soft on the right and left edges when close-focusing. No close up lens will help. Working on another solution . . .
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Old July 12th, 2006, 11:35 AM   #6
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While the bokeh is even (diffuses in all directions the same amount), it's still not diffusing thoroughly enough. What GG material are you using, if I may ask? If it's a thin-film focusing screen you might be able to double-up on it and get more pleasing results. I've become more of a diffusing 'fiend' if you will so I might be more picky than others.

Quote:
Why you guys are still using 50mm lenses for this game, I'll never know . . .
Can I ask you to elaborate? Ever since I started the 35mm adapter thing I've really been in need of a lens expert of sorts--actually I probably speak for a lot of us here by saying that. Since you test lenses you're probably the right guy to talk to.
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Old July 12th, 2006, 04:57 PM   #7
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It's a cheap, but very good, Canon EE-a 'plain' focusing screen, fitted as standard to the Canon 5D.
http://www.bhphotovideo.com/bnh/cont...ist&sku=402203

Trouble is, it isn't plain. There's a faint central ring about 22mm in diameter. The knack is to frame a 16x9 inside it. The HC3 handles this OK, but under extreme macro duress the corners peg out. Stacking another achromat (currently I'm only using a Leica 4D Macrotar) might push the screen beyond the macro's soggy corner zone which appears to be troublesome in the 1-2cm range. The achromat would be needed to enlarge the centre of the (more distant) screen, too. I'll snatch something off eBay and try it. I suppose there's always the Brightscreen . . . or some of the new wax/chemical etch wonders - can anyone advise?

Tests using the Canon EEa and the Nikon D screen both revealed problems with certain lenses. I'd previously been told that lenses wider than Xmm, or slower than fX would cause vignetting. In truth, the difficulty seems to be with lenses with small rear (exit) elements. My Nikon 17-35mm, for instance, works brilliantly, apart from one blip in the zoom range where the rear element withdraws into the body slightly. The other critical factor is the size of the image circle. Though all 35mm lenses throw a circle big enough to cover 36x24mm (ie, about 50mm diameter), in reality, the longer the lens, the bigger the image circle, providing more even illumination and betteredge resolution. Actually, the real killer for grain is vignetting, especially with the bulky D screen.

If you look at the MTF charts, you'll find that most 85mm lenses are sharper than 50mm lenses wide open. And they cover 35mm more easily. For instance, sticking with Nikon, an 85mm f1.4 is sharper wide open than the 50mm f1.4 is at f2, and it throws a more evenly illuminated image circle. A truly great adaptor lens is the Pentax 77mm f1.8 Limited, and the new Zeiss 85mm f1.4 should be the ultimate - mine arrives next week!

It's also confusing to me why most adaptors are built for the Nikon mount. Over in the stills world, Nikons are notorious for their ugly bokeh - the one thing you really want to get right in a DOF-controllable adaptor! One particularly honourable exception is the AIS 50mm f1.2, which has a reputation - not always borne out in my experience - of being very soft wide open. I'm still not sure to what degree an HD image is capable of differentiating between higher resolution optics - I'm running some tests of my own, but I'd be interesting in the consensus view here . . .

All my digital camera bodies are Canon, but I regularly use Pentax K, Zeiss Contax, Leica, Nikon, medium format and even enlarger lenses on them. Go with Nikon, you're locked into a second tier lens system; go with a Canon mount, and the world is your oyster - more compatible mounts than most people care to try, and access to a spectrum of glass with quite different drawing qualities.
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Old July 12th, 2006, 05:02 PM   #8
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Having apparently dissed 50mm lenses, I have to say that all my test shots, and most of my film, are shot with the Contax 50mm f1.4 - my favourite compact bokeh lens. The Canon 85mm f1.2 gives nicer looking results (I'll post something later), but it's a beast to use and carry.
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Old July 13th, 2006, 11:22 AM   #9
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More testing re: HC3(E) shows that the soft corner problem is mitigated by zooming the lens to its widest setting. It's chronic at the tele-end of the macro range. This means a bigger image on the screen: I either stick with the camera's macro facility and throw it a medium format image circle, or I stack achromats and use use the regular/tele part of its zoom range. Will try both . . . any ideas on the best material to use for a static 65mm diameter screen?
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Old July 13th, 2006, 11:30 AM   #10
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so the blurring at the edges remains the same irrelevant of aperture?
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Old July 13th, 2006, 04:42 PM   #11
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Cool stuff, Mark. Keep it up! And very nice job on all your lens tests. Definitely keep on keepin' on!

Quote:
Originally Posted by Mark Welsh
Why you guys are still using 50mm lenses for this game, I'll never know . . .
Sure you do. It's because most dvinfo members don't have the budget for the lenses you're talking about.

A lesser reason so many people use 50mm lenses is that the field of view (about 46 degrees) is much wider than with an 85mm (about 28 degrees). Shooting run-and-gun with an 85mm means you often have to stand far away from your subject to get desirable framing. If you're speaking with someone, this feels very odd to them to be interviewing them or carrying on a conversation, from "way over there." Also, the footage is shakier than with a 50mm since the narrower FOV exacerbates any camera motion.

Since a 50mm-ish lens is considered equivalent to human eyeball FOV, people are very comfortable with the look of the footage.
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Old July 14th, 2006, 12:56 AM   #12
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Quote:
Originally Posted by Mark Welsh
Why you guys are still using 50mm lenses for this game, I'll never know . . .
I'll second to Bill and for me is things even worse. If You use crane with 35mm adapter You'll get answer. 50mm is waayy too much, 17mm is ok.
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Old July 18th, 2006, 10:38 AM   #13
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Mark, great work. I love the images. Very sharp in the focussed areas, bokeh quite good as long as DOF is not pushed to the extreme (I like shot 2 and 3 more than shot 1).

Has the screen got any fresnel lens element on its back? Or did you use a convex lens to get rid of the hotspot? Was there a hotspot at all?

If you frame a 16/9 image into a 22mm circle, don't you lose something like 1/2 of the screen's surface and hence turns a normal lens into more of a telephoto?
Just wanted to make shure I understood you correctly. Losing some of the screens surface is not really a bad thing, it gives you the kind of super 16 look and a better DOF with lens full open - yes I like "semi-shallow" DOF.
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Old July 18th, 2006, 04:23 PM   #14
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There is a fresnel etched on the rear on the screen, but when reversed, it's practically invisible. The fineness of the grain on this screen (far better than the Nikon D) is borne out by the fact that these shots were effectively at 50% magnification! No condensor, no achromat, no moving parts. I shot some video with it last week, being careful to leave the frame edges OOF to disguise the unsharpness there. It looked OK on the projector, apart from the inevitable dust, and some occasional artefaction. Will edit and post later.

Incidentally, my whole adaptor unscrews and is made from off-the-shelf photographic components I had lying around. The main body of the thing is an extension tube. Will post pix also . . . it's relatively tiny: about the same length as the microscopic HC3 - with the lens on!
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Old July 18th, 2006, 05:42 PM   #15
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Mark, great job! please keep posting more tests, i am very interested in the HC3 for its cost and picture quality. i know its not close to professional, but i have found ways around that and i hope to shoot my next film with the HC3 in combo with my own 35mm adapter and mattebox. the camera is so small, i even am thinking about housing it inside a body to Pimp it out even more.
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