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December 30th, 2004, 01:04 PM | #16 |
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It depends on the thickness of the wax. If it's thin enough, you can get a very bright image. I just recently got a really thin layered wax adapter, but I want to do another and shoot for a completely bubble-free version. If I succeed, I will post some uncompressed framegrabs comparing it and my AO5 glass adapter.
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December 30th, 2004, 01:36 PM | #17 |
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ground glass test
I think this is a shot made with the opto sigma 1500
http://www.liisikoikson.com/ftp/noise_redux_ex.jpg this also contains the chris rubin workflow which looks to remove whats left of the grain in a static adapter |
December 30th, 2004, 09:20 PM | #18 |
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Richard,
that is not optosigma, but a 600 grit sandblasted glass. Optosigma gg grain is much finer and not really visible on a fine-detail image of that particular size. Chris |
December 31st, 2004, 03:24 AM | #19 |
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So, there would be hardly any grain from a 1500 GG? I wonder, what is the difference between grinding your own glass, and buying one premade? Does it work out alot more cost effective D-I-Y, or do you get a better image with a bought glass?
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December 31st, 2004, 09:15 AM | #20 |
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ground glass
chris your first image ,did look like more grain then I am seeing
with the 1500 ,. and maybe a good indicator of what the royln 500 grit will look like. and for all my efforts hand grinding, I was never able to make a piece of glass as good as the one I am using now. the next idea is to see if we could get the company to cement the ground glass to the plcx in a dust free room . dust is my biggest problem now |
December 31st, 2004, 10:12 AM | #21 |
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static adapter
chris I may be adding a second plcx to the adapter.
I just tested the system on a tv chart and I am seeing a slight barrel distortion. I think a matching plcx on the opposite side will correct this . this is a link to a german patent for the movie tube it has a wax diffuser in between two plcx . If we could get opto sigma to make this as one piece we would be set . I don,t think we have to worry about patent infringment because we are mearly buying off the shelf lenses and arranging them in a specific order in the tube and sharing the order http://v3.espacenet.com/textdoc?DB=E...QPN=DE10240076 |
January 1st, 2005, 04:18 AM | #22 |
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Richard, do you have any idea if OptoSigma take international orders? I had a look at their international page, but it was more for a laser optics firm that stocked OS equiptment related to lasers. If not, have you seen any optics sites that may ship the UK?
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January 1st, 2005, 06:59 AM | #23 |
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Steve,
The Optosigma dealer in the UK is: http://www.laser2000.co.uk/ Richard, I use this in my adapter: http://www.surplusshed.com/pages/item/l2030.html No barrel distortion, but difficult to position inside the adapter because it has no flat surfaces. I'm still working on it, but I'm sure I'll get it done. |
January 1st, 2005, 07:33 AM | #24 |
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Chris, thanks for the link, the trouble is it seems they don't stockground glasses there, just the laser side of OptoSigma. Now, I may be wrong, but I'll give them an e-mail to see if they do the ground glasses. Also, what camera were you using in your test, Chris?
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January 1st, 2005, 08:06 AM | #25 |
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Steve,
that was XL1 with stock lens |
January 1st, 2005, 06:16 PM | #26 |
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Richard Mellor-
Increase the distance between your GG and video camera a few inches and zoom in a bit more to reframe again. You shouldnt have any more barrel distortion problems. |
January 1st, 2005, 06:28 PM | #27 |
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i got barrel distortion with my adapter.
condenser as GG and macro only. Then i add a lens (looks like a huge contact lens) between the macro and the GG-condenser. moving back and forth vary the barrel effect (positively and negatively) but a finally found a position where barrel disappear. The best of all it is that it gives me the brightest picture i ever dream and totally remove the vignetting. |
January 3rd, 2005, 02:22 AM | #28 |
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Giroud, you say your adaptor gives a bright image, could you perhaps divulge any more information about the type of lenses your using, ect?
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January 3rd, 2005, 12:53 PM | #29 |
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static adapter
brett :I added a1/2 inch tube to the system as per your advice. and your right the barrel distortion is gone.
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January 3rd, 2005, 01:24 PM | #30 |
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as many builder, i unfortunately work with refurbished elements wit very few (if none) data about them.
My GG is a lense 55mm diam very thin (1mm in the border and 6 mm in the center). It has been taken off of a TV camera lense (Fujinon-TV Z 1:1.7/10-140), one of the front lens. The macro is a 52mm achromat from surplus shed, but except diameter , i have no information (works well with my VX2000) the "contact lens like) is another lens from the fujinon. For the GG i used AL. oxyde 1000. I is very fast to obtain the proper result (when the lens is flat!), because almost every lens i tested until now, is never really flat, so the first stage is to use abrasive paper (starting with 200 then 600 ) to make it flat. fortunately, the result is almost perfect, with no grain visible in normal light. Low light with iris closed increase the grain visibility, but having filmed at night, i can say it still workable. The real secret is to have a 35mm lens with big output. Most of lenses have a rear lens with diam. ranging from 15mm to 20mm. So you get a small bright output just behing the GG. So when the camera see the GG, if it is not really opaque, you can see the bright spot. I use now a Nikkor 1:1.4 that has a 30mm rear lens. if you compare to the diameter of the GG picture (about 47mm) you can imagine that really make a difference. additionally the angle of incoming light on the GG is a lot better. |
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