preset m42 lens ?

[ricstew]

Today I scored a long lens. 400 mm 6.3 m42 ( around 600mm on a crop body ?) I have whacked it on the camera and had a quick play.....now I need some tips? hints ? on how to use it. It is an early preset with the 2 aperture rings.....I have googled it but its not making much sense ....I set the front aperture ring to one f-stop and then the back one to another? How do I know which to set to what? and why?
and is there some way to tighten up the tripod collar? It seems to be all in one piece but it rotates around the lens
So if anyone can explain the basics to me I would be eternally grateful
cheers
Jan

[davidd]

I had a preset aperture lens back before time began....

How it works is you set the back (i think) ring to the aperture you want to shoot at, while the actual aperture stays wide open for focusing. When you want to take the shot, you turn the front ring to match the (preset) back ring, which closes the lens down to the selected aperture. You can get quite good at focus, stop down, shoot, open up again autoamatically.

I am not sure which ring is the preset, and which stops the lens down, but just see which one actually closes the aperture, and preset with the other one. It allows you to manually close the lens to your selectd aperture without having to take your eye away from the viewfinder.

Good luck!

I should add, the camera I had with the pre-set lens was completely manual everything, with no light meter inside. I had to use an external light meter, choose my shutter speed and aperture, then set them on the camera. I am not sure how you would use one on a DSLR. You would have to be in Manual exposure mode, and already know what shutter and aperture you wanted to use... I am not sure if the camera's meter will work with a pre-set lens?

[ameerat42]

I have such a specimen, at present on loan to a friend in the country, so memory must serve. You set one ring - is it the back one? - wide open, then you focus, set your desired shutter speed, and then stop down the front ring until you meter the exposure correctly. That's it. Shoot. Don't expect anything fast to happen. Enjoy the photographic life "as time goes by".

OK, you can set your camera to Av, or Manual, then make your adjustments, and hope that the shutter speed doesn't drop to several seconds.

Would you be able to post a pic or 2 of it? Just to verify it's something like the one I have.
Ta. Am.
Edited addition. They usually have "quite reasonable" IQ, because they are a fairly simple optical design with very few demands on the optical elements. And they are quite stopped down, (typically f/5.6-f/8) so eliminating lots of otherwise potential lens aberrations.

[ricstew]

Thanks guys.......I still dont get it lol but I think I have more of an idea I will play again tomorrow and see if I can work it out. The couple of shots I took today seemed fairly sharp to me.......even when I had it set to 50mm and wasn't quite sure which end to look thru! Batteries are flat so will charge them up and take a few of the lens in my lunch hour I am enjoying my photographic life......love it when time goes by!

[ricstew]

So I found some info on this lens......http://www.butkus.org/chinon/booklet...mex_lenses.htm its amazing what you can find ! I also had a bit of a play after work...lunch didnt happen today For some reason on my K5 these pictures exif data is incorrect...the data tells me f2.8 when I know thats not possible. I also need to find a thumb screw so the collar doesn't rotate......maybe not a million $ lens but not too shabby to play with!




cheers
Jan

[davidd]

The exif will never be correct for the aperture with this lens, as the camera has no way of knowing what the lens is set to.

[KevPride]

Yes they are certainly worth playing with - the optics are usually very sharp - especially if it is a Chinon.