f2 Summicron Collapsible [Focusing]

[Underaglassbell]

Good evening,
Recently I finally managed to obtain a 50mm f2 Collapsible Summicron lens for my M7, See: http://www.rangefinderforum.com/forums/showthread.php?t=94990

Today I have received back my first set of images taken with the lens.

Unfortunately, I seem to have messed up most of the shots, which out of focus.

I've attached a couple of examples to show what I mean, It seems as if the focus has jumped to a point that does not correspond with the viewfinder information.

Take the second image, the Wooden statue, I know for a fact I had the focus bang on in the viewfinder, yet in the image, the focus is in the background.

Why would this be?

The lens was not collapsed when I took the shots - I know you have to lock the lens by turning it after it has been extended, but I would be grateful if some users of this lens could offer some advice.

I love the lens, and I'm so happy I finally have one. But I am now worried about this focus /issue/.

Regards,
DaN

 

[mfogiel]

You have to do a focus test, follow the instructions here:

http://www.soniko.com.ua/site1/doc/focus12.pdf

If the lens is completely off, then return it if you can, else, send it for proper alignment, obviously I take it for granted that your M7 is focusing correctly with other lenses, otherwise the problem could be in your rangefinder collimation - you can estimate this pretty easily, by setting an M lens to infinity and pointing at the moon to see if the images coincide.

 

[FPjohn]

Is it locked and fully extended?

yours
FPJ

 

[Underaglassbell]

You have to do a focus test, follow the instructions here:

http://www.soniko.com.ua/site1/doc/focus12.pdf

If the lens is completely off, then return it if you can, else, send it for proper alignment, obviously I take it for granted that your M7 is focusing correctly with other lenses, otherwise the problem could be in your rangefinder collimation - you can estimate this pretty easily, by setting an M lens to infinity and pointing at the moon to see if the images coincide.

Thanks,
Yeah the M7 is perfect with my 50mm Zeiss f1.5 sonnar and 15mm vort'
- I don't think I can do the Lens test. I don't develop my own film.

So I would need to sacrifice a roll of 'pro' film or more likely shell out on some cheap film then get it processing + CD Image.

It could well be a user error, this is the first time I have used a Collapsible lens, so perhaps I forgot to lock the lens. I was Collapsing the lens after most shots then extending it again before taking a shot..

 

[Underaglassbell]

Is it locked and fully extended?

yours
FPJ

I could have sworn it was, but perhaps these images are proof the lens was not locked down.
- Would extending the lens and not locking it down cause this?

 

[FPjohn]

Yes.

Pull or push gently, the barrel should not move. To lock: gently pull 'til the barrel stops and turn until it will turn no further. Push gently, no motion shows the lens is locked.

yours
FPJ

 

[Sonnar Brian]

As stated, it must be locked into position for a good test. The focus is behind the main subject, which means the optics were too close to the film. A tenth of a millimeter makes a big difference in focus.

 

[Underaglassbell]

Thanks guys your absolutely right!

Check the first image I took with this lens:

@f2

Somehow I guess I have not locked the lens into place - annoying, but at the same time relieving as it is my error and not a problem with the lens! 🙂

 

[Sonnar Brian]

That one looks good. Next roll of film, check wide-open at a few distances. I suspect your problem was not locking the lens into place.

A misassembled lens, or one assembled from different lenses, "could" work at one distance, and not others. I had that happen once with a Collapsible Summicron, but got it sorted out.

 

[Underaglassbell]

I really hope mine is ok, I mean if it need to be fixed then so be it, but I just hope the issue was my fault and as you say not a case of the lens only working at one distance..

Unfortunately my next roll is Kodachrome and I'm already on shot 18 / 36
- I may hang fire and switch back over to my Zeiss Sonnar just incase and then try again with the Collapsible Summicron on my next roll..