92111 wrote: ↑Mon Nov 26, 2018 11:22 am
Hi mrsonchus
how can i get right from left
Did you get an answer to that question?
You can unscrew this intermediate lensgroup using one of those 2 prong lens repair tools. What comes out is 37mm wide and has a 0.75mm thread.
I thought it was 37x1mm so ordered a 37x1->42x1 mm ring. A threaded 50mm (I would go for the 70mm version next time,) m42 extension tube and a 45x1->42x1 mm ring. Already had some m42 macrotubes.
Put the 37->42 mm ring onto the 0.32x lens (oops, it will catch, but don't use force or you'll damage the threads)
Screw this combination into the extension tube, with the markings pointing away from the camera. More see below.
Put the vario orthomat eyepiece in the 38mm port, screw on the 45->42 ring. Next a macro ring, this lenght isn't critical. Next the extension tube with the 0.32x inside. On top a m42 -> your camera mount, in my case sony e-mount.
Early measurement put the lens at about 80mm from the film plane however this lenght is critical and has to be adjusted to within 0.2mm. Doing so is fairly straight forward though. All you need is a stage micro meter and a plan objective.
Focus though the normal eyepieces. Take a look through lifeview on the camera. The centre of the image should be in focus at this point. However the image will be out of focus at the edge (use a low power plan objective on the scope and the zoom focus assist on the camera). At this stage it is advantageous that the 0.32x lens is slightly too high up the extension tube. By slightly unscrewing the adapter you're extending the lenght by 1mm/turn. Next screw the 0.32x lens down by the same amount. If you needed to insert 1cm, screw down the lens with 10 turns. Go back an forth though this until the edge is in focus. Don't adjust the focus on the scope.
In my situation the 0.32x ended up near the bottom of the 50mm tube, the macro tube at the bottom keeps the 0.32x into place because it is just touching it.
- 0.32x lens inside 50mm m42 extension tube
- 20201123_211456-02.jpeg (132.94 KiB) Viewed 10496 times
The combination is now ready for use.
Btw that 45x1 is also found on the clamp that fits over the trioccular tube. Here with a periplan gw 4x high point.
- 127237082_10224137875343007_3677531366607768613_o.jpg (126.03 KiB) Viewed 10496 times
The image stays in focus while turning the zoom ring on the eyepiece, and with different objectives.
Did try a setup without the 0.32x and the image would one be in focus at one setting of the eyepiece. Not acceptable.