Manual Focus Lenses Forum

Nordentro · Expire: 2015-01-29

I did some work on a Fujinon 25mm f/1.4 today to fit into my c mount adapter.

Before

After a couple of hours under a "Dremel" Very Happy

(I had to cut of some of the backplate to make it fit)

Couple of samples after surgery:

It covers the sensor but with som heavy light loss to the edges and it has infinity focus.

pat donnelly · Wed Jun 30, 2010 12:06 pm

Great lens! Good coverage too for the focal length.

A six figure serial number!

Useful info in the hunt for lenses! Thanks.

Nordentro · Expire: 2015-01-29

It's not a bad performer after it was modified, but it's a bit sad to cut of pieces of the lens to make it fit.

I still think it was better to do the modification in order to make it useful and "alive" rather than standing in a dusty corner seeing all his buddy's going for a walk Laughing

Nordentro · Expire: 2015-01-29

Another update from this lens Very Happy

100% crop

mmelvis · Expire: 2015-05-09

Nice capture of the bee in flight

pat donnelly · Tue Jul 06, 2010 2:27 am

Wicked!

WICKED!

I love it! Post it on the www!

pat donnelly · Tue Jul 06, 2010 2:32 am

You might want to devise or acquire a baffle to use the lens at a distance? It will restrict the stray light most visible at the edges of the lens view.

Nordentro · Expire: 2015-01-29

I like the dark corners the lens produce but the corners will lighten up if I turn the aperture down to around f4 - f5.6 Very Happy

pat donnelly · Wed Jul 07, 2010 8:45 am

Using a baffle will remove some or all of the smearing or fluttering of in focus but off centre subjects. You can see how the leaves of the trees are different from one another in their rendering by the lens?

It will not affect the vignetting seen.

edz · Joined: 20 Aug 2009 Posts: 82 Location: UK

Have you made any successful baffles for c-mount Pat? For most c-mount lenses it seems like it would be quite hard to do since there isn't much space to work with behind then lens.

pat donnelly · Thu Jul 08, 2010 2:12 am

Hi Edz!,

No, I have not. Here is a thread with some more coherent details:

http://forum.mflenses.com/carl-zeiss-jena-sonnar-2-8-40-on-e-p1-t29189.html

The main idea from other threads seems to be to get any object that can fit, black metal or plastic sheet with only a little thickness, cutting a suitable hole therein. Existing baffles can be made from a larger Waterman stop, actually apertures for much larger lenses, that is cut down. One method occurs to me involves two thin sheets of a material, together making a baffle that can then be enlarged by adjusting the two pieces of material. Some CS lenses have apertures with only two iris elements. Therefore they have a shape of a ninety degree angle on each, which then become opposite corners of the baffle. Applying some super glue, when satisfied with the baffle at the widest aperture of the lens when the phenomenon is worst then may be tricky. It might be best to do this to the mount itself rather than the lens, but the possibility is that another c mount lens using that mount may not be perfectly suited.

The effect diminishes with a smaller aperture.

KhanX · Fri Aug 13, 2010 2:34 pm

Great shoot, I love all pictures.