u/Mysterious_pt

I was buying this petzval lens for my speed graphic pacemaker. However, I realized it has a huge thread (85mm) when I received it.

The Graflex board is 93x94mm, will an aluminum board still be strong enough to hold the lens if I cut a 85mm hole on it?

Are there better ways to mount such lens?

Thanks!

I unfortunately bought a THD Pentac 8" recon lens with fixed flange that cannot be removed. Most customized Graflex mount for this lens are for the versions that you can unscrew the flange.

However, I recently found on ebay a copy with 3D printed mount that is compatible with the flange. Has anyone seen this lens board before? Can I find the stl file or purchase one somewhere?
Thanks

Recently

I recently encountered a Darlot lens with interesting markings. The images posted here are from the internet of a similar lens.
In addition to Darlot and the serial number, the lens has the barrel and front element labeled B, and rear element labeled A.
Does any one have information on this lens except for it being a petzval? What's the use of the marking? I would assume it might be convertible with one element removed, but which and how? Is there any catalog describing such lens?
Thanks

Base turned out weird on my TMax400 recently developed in Tetenal Ultrafin TPlus, fixed in ilford rapid fixer for 4.5min in rotary. For reference the last image was done in same formula last year.
The fixer I used recently was prepared 3-4month ago and used on 5-6 rolls.
Is it fixer gone off within 1 year after opening, or preparation expired? Stock bottle half full and preparation always in full bottle.

I recently ordered in a ~1900s projection lens. With the mindset that lens is not coated, I wasn't paying too much attention to the glass condition and considering the surface simply being dirty.

However, I start to worry after noticing the pattern looks a bit like corrosion of the actual glass. I don't know whether or how bad exposure to alkaline environment sometime over the past century could lead to an even corrosion of SiO2 like this.
This is the 2nd 100+yo lens I've bought so I don't know a lot about what to look for on those old glasses. Is it a valid concern?

Thanks

Embarrassed enough I only recently realized that the focal plane shutter can be triggered by attaching a cable.

However, with my camera the trigger has always been so stiff that I have to push it all the way in. With a cable attached (a cheap one with plastic sheath) I cannot trigger the shutter when the button on the cable is fully pressed.

Previously I have serviced the shutter mechanism, but the inside of the trigger mechanism is not accessible unless the wooden chassis is taken apart. So I just put grease to where I could reach and hope it could work in. Apparently not helping.

I wonder what's it like with your cameras. Does the trigger also need to be fully pressed in? Can I get away by replacing the cable with longer pin or stiffer sheath?

Thanks

I got this collapsible Summicron a while ago, the front element is as-is but the image is still very usable so I'd give it a second life.
Recently I noticed the internal developed a thin layer of haze and a tiny fungus.

Before opening it for cleaning, because this is an old design without internal lens element mounts, I wonder how I could preserve the optical alignment without messing up the axis.

Do you mark the relative position of the element to the lens tube? If so, how and what pen/tool would you use? Thanks!

Hi I recently hot this M1 and upon close inspection I noticed this hole is meant for a missing screw.
I wonder if it's anything important and whether taking the camera out like this will cause light leak.
Thanks!

Recently I ran into a Cooke II lens like this, which does not fit in the description I could find online.

There is no engraving on the front, no soft focus adjustment. And the 8.2 eq focus is different from anything in the catalog. Does anyone know about this lens?