View Full Version : PCX (Plano-Convex Lenses)
i was told if i added a plano convex lens to my adapter right after the gg and b4 the macros it will reduce the vignetting so i dont have to zoom into z50... i was gunna get a 50.8mm BK7 Plano-Convex lens from thorlabs but i am not exactly sure what wavelenght range i should get and what focol length i need... can someone please help me i am mad confused about now...
link to PCX (http://thorlabs.com/NewGroupPage9.cfm?ObjectGroup_ID=112&Visual_ID=1998)
Wayne Kinney
06-05-2006, 02:24 AM
I think the 100mm Focal Length lens will be your best choice here. Try and get a coated one. LA1050-A* looks ok.
.....it will reduce the vignetting so i dont have to zoom into z50...
Yes thats the idea. Make sure you have a 36x24mm frame in your adapter and use this as a zoom reference and NOT the vignetting.
Just a tip, there are 2 ways to reduce vignetting, 1: by adding a condenser like the Plano Convex lens and 2: by increasing distance between the camcorder and GG but this is linked to your other question on your other thread since your cam will only be able to focus on the GG at certain distances....
3: get a fast lens with larger rear element.
I found 2x 120mm FL PCX back to back worked best, GG PCX PCX Cam. Those could be replaced by a single BCX of 60mm FL I reckon to remove the glass/air/glass interface. The lens size on the cam will influence how much correction you need.
Wayne Kinney
06-05-2006, 03:54 AM
Yes, very true indeed.
The BCX (bi convex) lens will also help reduce barrell distortion which short FL PCX's introduce.
ok soo if i went with the F=60mm BCX, would it be ok to have this touching my diffuser? what should the dist be for this?? cuz i might have to make my adapter longer
soo i guess my adapter will be. 35 lens, diffuser, bcx f60mm? 2 asian +10's, 52-43mm step ring, dvc30
does this sound good? or should i get a diff bcx or pcx...
Wayne Kinney
06-05-2006, 08:03 AM
Sounds good, except the 2 asain macros, with theses the image will suffer. Please PM me as I may be able to get you a suitable achromat.
Forrest Schultz
06-05-2006, 12:37 PM
yes....thank you wayne...
Wayne Kinney
06-05-2006, 01:18 PM
And no, i have not forgotten your free GG, Forrest.
Forrest Schultz
06-07-2006, 07:58 PM
haha, i thought you had, which is totally fine, i mean, free is never free, and i never want to ask for that which i shouldnt ask. Thank you Wayne, its just been so long, i had thought you had forgotten, so i have been testing a variety of gg's. again thank you, let me know what happens.
Wayne Kinney
06-08-2006, 04:04 AM
OK Forrest,
I like to help out all the DIY'ers on here and have send countless free items to users, im just a little busy right now. Anyhow, lets get back on topic.