LTM collapsible advice

[msbarnes]

I'm looking for a collapsible 50mm, or maybe two because I can't decide between size and speed.

small/compact lens (f3.5)
Leica 50mm f3.5 Elmar
Cosina 50mm f3.5 Heliar

larger/faster lens (f2)
Leica 50mm Summitar
Leica 50mm Summicron
Cosina 50mm Heliar

Questions
1. There are a few ltm elmars, which ones had 39mm filter threads? just the f2.8?
2. Are the Cosina lenses 39mm filter threads, i would think so, but I want to make sure.
3. Anyone have a size compaarison of these lenses? I'm not sure how the Heliar (slow and fast variants) stacks up against the Elmar /Summicron in terms of size.

[msbarnes]

to the moderator, I realized that this might be more appropriate in the rangefinder thread so feel free to move this there.

[250swb]

To give you an idea of the Leica lenses the collapsed distance it sticks out the front of the camera, minus lens caps or filters is

3.5 Elmar 12mm
2.8 Elmar 21mm
2.0 Summitar 24mm

I'm not sure about the LTM Summicron but would assume it will be about the same as the Summitar. You can get an adapter so the Summitar can take 39mm filters, and I think you can get a slip on adapter to take 39mm filters for the 3.5 Elmar.

Steve

[Jim Jones]

My collapsing Summicron extends 27mm from the front of the camera. It was a much used lense for many years. Tests suggest the 2.8 Elmar is even sharper.

[darkosaric]

I would say go for one lens - compromise between size and speed: elmar 2.8.

[msbarnes]

That is my current thinking.

I feel that it is better to go 50mm f3.5 Elmar (for size) and 50mm f2.0 Summicron (speed/performance) or just compromise with a 50mm f2.0 Summitar or 50mm f2.8 Elmar. But the purpose of a collapsible is to be compact, the the Elmar might win, and it is easier to deal with filter-wise (39mm, i believe?)

[250swb]

Yes the 2.8 Elmar takes 39mm filters, and it is a better lens than the Summitar overall. But the Summitar is popular because of its rendering, a glow wide open, sharp stopped down, and a curious bokeh that some like and others don't.

Steve

[georg16nik]

Summitar got noticeable comma up until ƒ/5,6, collapsible Summicron is a bit better, I am talking about good samples not dog lenses.
The Elmar ƒ/2,8 is very interesting lens but LTM Elmar ƒ/3,5 got unique rendering due to diaphragm position after the the 1st element and other optical specifics, also a much smaller lens than anything 50mm Leica.

[darkosaric]

LTM Elmar ƒ/3,5 got unique rendering due to diaphragm position after the the 1st element and other optical specifics

Hi Georg,

Are those unique characteristic also valid for Industar-22 lens? They have same diaphragm position?

tnx

[georg16nik]

Hi Georg,

Are those unique characteristic also valid for Industar-22 lens? They have same diaphragm position?

tnx

Industar 22 diaphragm is located before the rear group and the glass is different from Elmar LTM.

Leica relocated the diaphragm later in Elmar ƒ/2,8 and changed the glass.
The black Elmar ƒ/2,8 M is supposedly the most fine tuned Elmar derivative.