Recobering from a bad back, with three days in bed,I wanted to see the halos of my 35/1.4 non-asph (wide open), the only way I found was placeing the leica M lens on a nikon fm body, I could see those halos; in a very out of focus, but those were there, presence of flare could be seen in other lenses, halos only in the 35´lux.

Does any one know if I can find a tube with a M mount and a fresnel glass at the same distance than film on a M body? a leica M lens viwer...

do they exist?

so my question.

-- r watson (al1231234@hotmail.com), March 19, 2002

Answers

Take the bottom off your Leica M. Hold a piece of tracing paper or fresnal glass an the rails. Set the shutter to B press and hold the shutter release. WAH LAH!

-- Alfred Henry (J Henry@provide.net), March 19, 2002.

Forgot for prolong use leave the rear door up put the bottom back on and get a locking type of shetter release. You can even mount the camera to a tripod. This set up allows you to check the accaracr of your range finder and the depth of field of any lense at any F stop by simply using a tape measure and three targets. Place one at a set distance from the film plane focus. Then place the other targets one in front and one behind the focused target move them until they reach the break point where they begin to go soft. Have fun. OH don't try this at infinity how fer can you walk?

-- Alfred Henry (J Henry@provide.net), March 19, 2002.

Actually, there are "viewers" available. I don't know what they're called, but I saw two of them on eBay a few months ago. It was listed as "Leica M lens viewer" (!)

:-),

-- Jack Flesher (jbflesher@msn.com), March 19, 2002.

thank´s, I´ll look in ebay to see if I find one, Jack.

Alfred, thank´s for help, I have already done that, but is not so comfortable for moveing around, and yes infinity can be very far.good to know you got my idea.

-- r watson (al1231234@hotmail.com), March 19, 2002.

I've took a broken piece of 4x5 ground glass and had it cut into strips by a framing shop so that it fit between the film guide rails of the M. I put a little bit of tape on two ends to keep from scratching the film gate and protect my fingers from the sharp edges, and it works like a charm, and a little more accurate than tracing paper (although that was my trial run). One of the best ways to check what's happening at the film plane...

-- Carlin (carlinm@abac.com), March 19, 2002.

Forgot to add, I usually get a locking cable release and set the shutter to Bulb. You can take the whole back door off, and you've got yourself a viewer. Just remember to put the matte side toward the lens, because this will effect your distances. You can check rangefinder accuracy here, as well. Pull your eye back from the viewfinder and you can compare when you find the right spot! Not to be taken lightly, as you can damage your shutter this way, but I've been doing this for quite a while and haven't broken a single piece of glass and never a shutter problem...

-- Carlin (carlinm@abac.com), March 19, 2002.

FWIW, you can also "aerial" focus an image through a loupe without any type of imaging surface like tracing paper or groundglass to focus on. This technique is often used in critical situations to focus a view camera. You do need something at the plane of focus -- like a piece of fine wire or strip of scotch tape -- for your eye to focus on, then the "aerial" image will appear in your loupe.

:-),

-- Jack Flesher (jbflesher@msn.com), March 19, 2002.

Ok there are lots of ways to see a proyected image on or off a Fresnel glass.

My reason of a M lens viewer is to analize in a moment, without the need of slides or prints, how a lens can handle side ligths, or in frame ligth sources, or just to see if a shade hood realy helps or not, things that can be judged on a ground screen, without the need of enlargements.

A solid thing where you can mount a lens and see can be my dream for this week, and if I can add something I would like a larger screen so to see the all proyection area of a lens, with a 24x36 frame marked.

I thougth there was already such a tool.

-- r watson (al1231234@hotmail.com), March 19, 2002.