Aluminum Tubing and UV filters
Aluminum tubing that has a big enough I.D. with a fine metric thread has been hard to find. Im sure they exist but as of yet I havent found ones that are ready made. What you can do is have someone take aluminum tubing stock and cut threads into them. Make sure you have enough threads to expand the difference between the flange focal length of still photo lens and motion picture lenses as it is greater than what a stepup ring can provide. Even better would be sometype of lens housing minus its optics or a adjustable length extention tube. Both would have to have large I.D.'s especially on the camera side of the GG.
Also your extra UV filter (the one you use to block the dirt from getting on your ground glass) should have a antireflection coating on it because it faces right at the ground glass. -Brett Erskine |
Does anyone know of a link where I can find out the actual inner (female part) and outer (male part) diameters of various step-up rings? The local stores are not too thrilled to open sealed step-up ring packages to let me measure them :).
Also, I've read a few recommendations where it's advised to place the condensor lens in front of the GG ( i.e., SLR Lens -> condensor -> GG ) and NOT behind it, to minimize reflections. Has anyone tried to compare these two cases in practice? |
I've been trying to keep this project cheap, but I realize that I do need a closeup filter. Obviously, I need a two element solution to cut down on the chromatic aberration problem, so I think I've about decided on this:
http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=77546&is=REG Anyone else know of something cheaper? What about the Hoya filters...anyone using a 58mm achromatic diopter other than the Century Optics brand? Thanks! |
The +10 Hoya's are generally a better deal at about $70 but ideally you usually want to get a diopter no stronger than you need in order to avoid moving your GG back farther away from your camera to make up the difference. Getting the right kind for your camera will make sure your adapter is as physically small as possible in the end.
-Brett Erskine |
Jonathon Wilson where are thoughs condenser FL numbers?
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Dude - I"m still at work. I think I've been at my house for a total of like 6 hours total in the last three days. You'll get 'em once I actually see 'em :)
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Brett: I found an old post where you had a link to some of the Hoyas, but the ones in that price range weren't two-element, where they? I probably looked at it wrong.
Also, what strength would you recommend for a Canon GL2? Thanks! |
Send me the link or check out the part number with Hoya. Since I have a DVX100 and not a GL2 I dont know. Im pretty sure the info as already been posted. Otherwise your going to have to go to your local camera shop and test diopters out yourself.
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The problem is that I'm in south Mississippi. Not a high concentration of camera/video equipment suppliers here. I'd sure like being able to walk into a place with my camera and try stuff out, though.
Here is the link in question: http://www.2filter.com/hoya/hoyacloseup07.html My only option - the two-element adapter in 58mm size - only go up to +5, and are $111.63. |
Frank, here's a good link for achromats:
http://www.angelfire.com/ca/erker/closeups.html It also tells you how to calculate the focusing distance when adding a diopter, so you can figure out the lowest value that's useable with your camera. Like Brett says, go for the lowest value necessary to avoid spherical aberrations. |
I appreciate that link, Roman! Looks like a lot of helpful info at the bottom of that page.
Thanks! |
Frank I checked out your link. Thats the same price as I've seen for the Hoya +10 achromat macros but just call up the Filter Connection and ask to make sure.
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Please bear with my ignorance about optics.
There is all this talk about FL, help clear a few things up for me. SLR lens -> GG -> Condenser -> -> Macro -> DV OK I know that FL is important here SLR lens -FL> GG so the image on the GG is in focus. and I understand the basics about different color waves acting a little short or long in relation to each other. But is FL important anywhere else in this setup Maybe here SLR lens -FL> GG -FL> Condenser -> -> Macro -> DV or here SLR lens -FL> GG -> Condenser -FL> -> Macro -> DV Is the condenser flat side right up against the GG? Will the Hoya +7 or +10 work as the condenser? Thanks John |
<< But is FL important anywhere else in this setup >>
IMHO, no. As long as you can focus onto the GG image (with macro or without, depending on your camera), you're OK. << Is the condenser flat side right up against the GG? >> IMHO, yes, but Alain had his condensor with convex side up against the GG. << Will the Hoya +7 or +10 work as the condenser? >> Sounds like a great idea to me. The +10 diopter's focal length is 1000/10 = 100mm, which sounds about right, although I don't believe that condensor's FL is that important, since you put it right against the GG. |
fresnel & fresnel VS condenser lens
Some one have a idear which is the best fresnel lents to use .
I find few on edmund optics website whit Effective Size diamater of 2" but different type: IR fresnel http://www.edmundoptics.com/IOD/DisplayProduct.cfm?Productid=2042 Aspherically Contoured Fresnel Lenses http://www.edmundoptics.com/IOD/DisplayProduct.cfm?Productid=2039 PCX visible fresnel http://www.edmundoptics.com/IOD/DisplayProduct.cfm?productid=2040 some one test both solution to avoid hot spot : frenel & condenser some info best solution last question.. some one test whit boss screen ??? Ciao |
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