View Full Version : Direction of aperture ring, focusing

03-03-2009, 05:12
Roger, in your excellent "Rangefinder" book, it is stated that you find the M6ttl and M7 unusable because of the direction of the shutter speed dial (given that you are used to the direction used on the older cameras). I appreciate the importance of being able to use the reflexes one has built up over decades.

But then how about aperture rings? Are they standardized within M-mount lenses? Not that it matters to the M-system, but on my OM-Zuiko (SLR) lenses, the aperture rings moves in the opposite direction to stop down. Is there any system to the direction of aperture rings, e.g. rangefinder lenses go one way, SLR the other?

How about focusing? On the cameras I am used to, one turns counterclockwise to go toward infinity - is this always the case?

Thanks for your great writings.

principe azul
03-03-2009, 12:53
Focusing goes the same way in the same camera system, otherwise the roller cam in the rangefinder wouldn't respond correctly.

The Soviet Jupiters (at least J-3, J-8, J-9) have aperture rings that aren't click-stopped and that go the 'wrong' way to Leica, i.e., engraved scale runs 16 - 11 - 8- 5.6 - 4 - 2.8 - 2. As well as the lack of click stops, there's usually different spacing between whole stops (big gap between 2 and 2.8, small gap between 11 and 16), something uncommon on modern lenses but found on the Nokton 35/1.2.

With click stops, Nikkor SLR lenses usually did whole stops, Leica and Voigtlander RF lenses do half-stops and Zeiss RF lenses do third-stops. As I often change aperture without looking at the scale (sometimes if I didn't know what aperture I was at I'd rack a lens to full aperture then count clicks back to f/4, for instance), I sometimes have to pause if I'm using different lenses.

Anyway, that's the limit of my knowledge. Roger will be able to tell you things you never knew you didn't know!

Roger Hicks
03-03-2009, 13:48
Aperture rings are of course different from focusing rings, and as far as I am aware, go in both directions even on Leica. I suppose I find it easier to use the 'classical' direction (anticlockwise to stop down, with the cameraat the eye) but I have to admit that I've used both without undue grief. I'm not sure I have any 'backward' lenses left.

I have to add, also in all honesty, that although I've more or less got used to the 'backwards' shutter speed dial on the M8/M8.2, it does slow me down on 'real' Leicas.

Focus can go in either direction, of course, but again, Zeiss switched to the Leica direction for modern RF lenses. Without checking, I'm pretty sure that Leica derivatives (especially Canon) go one way, Contax derivatives (including Nikon but not current Zeiss) go the other.

Interestingly, I don't mind focusing my Nikon Fs one way, my Leicas the other. The cameras are so different that the direction is built in, so to speak.



03-06-2009, 10:47
Thanks for the feedback. I like the angle that Nikons focus opposite of Leicas because Nikons were historically Contax derivatives so they focus the same way as Contaxes. I found a picture of an old Zeiss lens and it stops down by turning it clockwise, which is similar to Nikon but opposite of the typical Leica way, so there seems to be some historically explained system to the madness, although of course Zeiss has since changed the stop direction.

As Roger's post suggests, one can get used to either direction but when learning, I think it would be easiest to memorize the direction if turning clockwise equals smaller apertures and shorter shutter times. One can make an apt analogy to a faucet, which (in Europe, almost universally, and in the US, usually) restricts flow when turned clockwise. So you would restrict the light by turning the camera controls clockwise. As far as focusing, by analogy to the human eye, one can think of the outfocused (at infiinity) state of the lens as the relaxed state. Then it might be logical to "tighthen it down" to focus in. Maybe that's what the Contax engineers were thinking. Or maybe not.

03-06-2009, 10:52
All LTM/M lenses that I have used focus in the same direction, including Leica, Canon and Nikkor lenses.

Aperture movement is different however, but even varies across Leica lenses. For example, the 90/2 v1 is different from the 90/2 v3. But then it doesn't matter so much to me, since I always look at the lens when setting the aperture.


03-06-2009, 11:01
Focusing goes the same way in the same camera system, otherwise the roller cam in the rangefinder wouldn't respond correctly.!
Not true at all. I had a 90 Summicron (48 mm filter ring) that focused just the opposite of all my other lenses.

03-06-2009, 11:02
All RF Nikkors that I've used have aperture rings turning the same way.