Walz Envoy doesn't focus to infinity

[Brian Legge]

I stumbled across a Walz Envoy recently, remembered the comments here about it, and picked it up. The camera is a little beat up but the lens looked to be in good condition.

Unfortunately, the lens doesn't seem to focus at infinity correctly. At 30 feet, I get a significant amount of bokeh. I don't have any great examples scanned (as I wasn't a big fan of the result), but here is one example image:

http://www.flickr.com/photos/cannelbrae/4665284203/

I have to admit being a bit confused. I took apart the lens to see if perhaps an element was backwards but didn't find anything that could go in backwards. The assembly seemed relatively straight forward.

Any ideas or suggestions about what to look at next? I suppose I could ignore infinity focus and just align the rangefinder to match the lens if it comes to it.

 

[Sonnar Brian]

First thought that comes to mind is the Rangefinder might be off.

Did you focus using the Distance Scale or the Rangefinder patch?

The lens appears to be front-focusing a lot. I had one Sonnar with a rear group in backwards, and the center was sharp but the edges were completely off.

Post a couple more pictures. Also determine of the RF and Distance scale agree at infinity. We'll go from there.

This is the type of shot that i take to test the RF against actual focus:

Easy to tell how far off the focus might be, but does not help with finding backwards elements.

For the latter, an image with something more uniform helps.

 

[Brian Legge]

I finally got back around to this camera - lots of others I wanted to take a look at.

I think the issue is the third front element. There isn't any retaining ring around it or anything holding it in place. I think it gets close and moves around a bit. That explains why I had such a hard time looking through ground glass against the back and getting consistent results.

I don't know if it was originally cemented down or how it was secured. I'm reluctant to just glue it and hope for the best but that may be my only option at this point.

 

[Sonnar Brian]

I doubt it was glued in, this is a classic design of a lens. Not taking mine apart to find out, but sounds like a missing retaining ring.

 

[Brian Legge]

That would make much more sense. I couldn't imagine it was cemented originally. I guess someone else got inside the camera long before me. 🙂 I'll see if I can sort out the retaining ring size. Maybe I can find a replacement. Worst case, i try to pick up another beat up Envoy and use this one as parts.