LTM lens aperture ring/focus interplay question

[arubey]

After a decade or so of using a Leica iiif along with a 3.5 Summaron and 2.0 Summitar (both clean examples whose look works for me), I decided to pick up a Voigtlander Bessa R to use the same lenses and give in-camera metering a try.

This is probably just a matter of getting familiar with 'new' equipment, but it's taking me a while to adjust to metering in camera, and making necessary aperture adjustments without impacting focus, especially with the Summaron as it has click stops on the aperture ring. Basically, when I go to adjust aperture the whole lens turns, adjusting focus, unless I hold the focus knob in place or keep it locked at infinity. The Summitar gives me the same trouble but to a lesser degree as it doesn't have click stops. Focusing and aperture adjustments on both lenses are very smooth, it's just that the aperture ring is a bit 'heavier' than adjusting focus.

In my time using these lenses on the Leica I never noticed this issue as I would set exposure before composing and focusing. But now on the Bessa, my tendency is to focus as soon as look through the viewfinder, then I throw everything off adjusting the f-stop.

So my question is this. As I've never really looked at other LTM lenses, are all of them prone to this issue? Or have some, possibly more contemporary lenses, isolated the focus ring from the body of the lens?

Likely the best solution is simply to set my desired aperture before looking through the viewfinder, then adjusting exposure via shutter speed. It's just taking me a while to commit that to muscle memory...

Sorry for the long winded explanation, and thanks for any advise or info on contemporary lenses!

 

[Coldkennels]

They're not all that way inclined. Out of the Leitz LTM lenses I have here, the Summar, Summicron, and 135mm Hektor all have "static" barrels which do not rotate, so changing the aperture won't change the focus. The f/3.5 Summaron, 50/3.5 Elmar, and 90mm Elmar all rotate the whole barrel when focusing, leading to this problem.

(aside: I never actually noticed the 90mm Elmar barrel rotates, but the 135mm Hektor's doesn't. Visually, they're very similar, so I assumed they were the same.)

Out of my collection of LTM lenses, this is the list of the ones with static barrels:

• Leonon 50/2
• Canon 35/1.8
• Canon 50/1.9 collapsible Serenar
• Canon 50/1.8
• Summar
• Collapsible Summicron
• 135mm Hektor
• Voigtlander 15mm Super Wide Heliar
• Voigtlander 21mm Color Skopar
• Voigtlander 28mm Color Skopar

Lenses with rotating barrels:

• Canon 135/3.5 (all versions)
• 35/3.5 Summaron
• 50/3.5 Elmar
• 90mm Elmar

I think the general rule of thumb is if the lens is quite compact, there's more chance of the simpler "rotating barrel" construction. On those lenses, I tend to keep the aperture constant and change shutter speed more often for one reason or another anyway, which tends to negate any issues.

 

[arubey]

Thank you so much, Coldkennels!

I think I'll put in a bit more practice with my current Leitz lenses, doing as you mentioned - keeping the aperture constant and adjusting exposure primarily via shutter speed. If that doesn't work out, I may start looking around for a CV Color Skopar. I'm guessing the 35mm would share the static barrel design of your 21 and 28mm examples.

Thanks again!
Andy

 

[Saganich]

I'm confused, the OP seems to imply this was an issue also on the iiif? Neither of my Summitar's have this issue on an ltm body. Is the lens locked in place in the un collapsed position?

 

[arubey]

I'm confused, the OP seems to imply this was an issue also on the iiif? Neither of my Summitar's have this issue on an ltm body. Is the lens locked in place in the un collapsed position?

Hi Saganich,
No, this wasn’t an issue on the iiif. Or more accurately, I should say that the way I shot with the Leica (setting exposure first, then composing and focusing) didn’t require adjusting aperture after focusing, and therefore avoided what I’m experiencing with the Bessa. And yes, keeping the lens locked at infinity (and of course extended in the case of the Summitar) while adjusting exposure would solve the issue, and that’s something I’ll try. It just isn’t convenient when bracketing exposures for the same subject (not at infinity). But adjusting the shutter speed instead would usually be a suitable solution.

Thanks!
Andy

 

[Godfrey]

After a decade or so of using a Leica iiif along with a 3.5 Summaron and 2.0 Summitar (both clean examples whose look works for me), I decided to pick up a Voigtlander Bessa R to use the same lenses and give in-camera metering a try.

This is probably just a matter of getting familiar with 'new' equipment, but it's taking me a while to adjust to metering in camera, and making necessary aperture adjustments without impacting focus, especially with the Summaron as it has click stops on the aperture ring. Basically, when I go to adjust aperture the whole lens turns, adjusting focus, unless I hold the focus knob in place or keep it locked at infinity. The Summitar gives me the same trouble but to a lesser degree as it doesn't have click stops. Focusing and aperture adjustments on both lenses are very smooth, it's just that the aperture ring is a bit 'heavier' than adjusting focus.

In my time using these lenses on the Leica I never noticed this issue as I would set exposure before composing and focusing. But now on the Bessa, my tendency is to focus as soon as look through the viewfinder, then I throw everything off adjusting the f-stop.

So my question is this. As I've never really looked at other LTM lenses, are all of them prone to this issue? Or have some, possibly more contemporary lenses, isolated the focus ring from the body of the lens?

Likely the best solution is simply to set my desired aperture before looking through the viewfinder, then adjusting exposure via shutter speed. It's just taking me a while to commit that to muscle memory...
...

(bolded) Yes, that's what to do with lenses that have the focus ring in the front in any configuration that can make turning the focus ring likely when you adjust the aperture.

Most of the later LTM and then M-bayonet lenses separate the focusing ring and aperture control ring completely so this is rarely an issue.

Regardless, just set the aperture you want to use before anything else, and then focusing and adjusting exposure with the shutter speed control works perfectly.

G

 

[jc031699]

(bolded) Yes, that's what to do with lenses that have the focus ring in the front in any configuration that can make turning the focus ring likely when you adjust the aperture.

Most of the later LTM and then M-bayonet lenses separate the focusing ring and aperture control ring completely so this is rarely an issue.

Regardless, just set the aperture you want to use before anything else, and then focusing and adjusting exposure with the shutter speed control works perfectly.

G

What G said-

You can negate this effect by doing an "aperture priority" strategy. Decide on your desired aperture for the scene, then adjust the shutter speed dial to get the exposure matched up. Won't have to touch the lens to change exposure.