Beginner's question about RF focusing

[thorsten]

Hi everybody,

I noticed something weird yesterday: So far I have never had any problems focusing my Zeiss Ikon, in fact, it is really easy to focus correctly... the camera seems to "snap" on the right point. But yesterday I focused on "infinity" for the first time and saw, that the two images in the viewfinder didn't match. So I tried a bit more and found out, that I always can match the two images in the VF when focusing from 0,7 meters to - let's say - 7 meters away, but if I have to use "infinity" on the focusing ring of my Biogon 2/35 the two images in the viewfinder never match but always are slightly side by side.

Since the Zeiss Ikon is my first rangefinder camera, I am not sure, if it's a real problem or if it's something normal for rangefinders. Could you help me out here?

Thanks,

 

[lubitel]

Try focusing on something very far away, like the moon. The images should be alligned. With a bessa (I read that its normal) objects that are closer than about 1 km away, the infinity focus will be a bit off. But farther than that they will be alligned correctly.

getting ready for your Italy trip? 🙂 I am going in 2 weeks as well.

 

[JohnL]

If you turn the focusing ring all the way to infinity until it stops, you may actually be a little past infinity. Some makers leave a little margin to allow for temperature changes, I believe. However, if on very distant objects (several hundred yards or more) you cannot get the images into alignment, then you have a rangefinder calibration issue. Not sure how easy this is to fix on the ZI.

 

[thorsten]

Thanks for your quick answers. I have to admit that I only tested focusing at things which are a maximum of about 200 yards away... I'll try to focus on something wider away just after work and until then hope to not have a misalignment.

JohnL, how do you get along with the "temperature margin" on focusing rings? The focusing ring of my Biogon 35 allows to focus up to 12 meters (don't know exactly 'cause I don't have it with me now), then the next "stop" is infinity. So how do you handle focusing on something which is about 200 meters away?

That is perhaps a better way to describe my problem: If I want to focus on a building that is - lets say - 150 meters away, the two images in the VF won't match, even if I turn the focusing ring to infinity until it stops. Is this something "normal" with a rangefinder?

lubitel, I'll go in 3 days and can't wait so long. 😉 I am "Urlaubs-reif". Where will you go?

 

[rxmd]

If I want to focus on a building that is - lets say - 150 meters away, the two images in the VF won't match, even if I turn the focusing ring to infinity until it stops. Is this something "normal" with a rangefinder?

No.

Well, it's "normal" in the sense that it's normal for a rangefinder to go out of alignment every now and then, but you should have it fixed. Or fix it yourself if you can do that on the ZI without losing warranty.

Philipp

 

[lubitel]

I am urlaubsreif as well 🙂 I will be in toscana in viareggio for a week. Still have to decide on my camera combo 😉 definitely the Bessa R with 35mm but which one to accompany it?

I wouldnt worry about your infinity focusing issue. If I see that the object is at least 20-30m away I just turn the lens all the way to infinity - at that distance your depth of field is huge anyway.

Have fun in italy and post some photos afterwards.

 

[jaapv]

If your photographs are fine and in focus: don't worry-take pictures 🙂

 

[Finder]

Your rangefinder patch should show focus up to infinity. If not, send it back for calibration.

BTW, rangefinders need object further away than a mile for the patch to be focused on infinity. The folks a Mamiya confirmed than for me with the Mamiya 6.

Also, rangefinder lenses do not focus past infinity like SLR lenses because focus is a product of a mechanical system which compensates naturally. Modern SLR optics require the ability to focus past infinity because of thermal expansion which the focusing system is independent from. AF also does not require tight mechanical tolerences on the lens focusing scale as the AF system will adjust focus based on a focused image rather than a specific mechanical position.

 

[thorsten]

Thanks again for your help. Unfortunately I don't have the time today to test focusing at an object about 1 mile away, but I'll do it tomorrow and will let you know how it went. Since *everything* on the Zeiss Ikon is great I strongly hope, that this will also be alright. 😉

lubitel, have a nice time in Toscana. I'll be not wide away, going to Liguria, one week on the "flower part", another week in the Cinque Terre.

Thorsten

 

[thorsten]

I just wanted to keep you up to date. Unfortunately, I really can't get the double-image in the vf-patch matching, even when focusing on "infinity" at a building about 700-800 meters away.

Now I called Zeiss Germany and have to say that I am really impressed by their great service, which nearly led to forgetting the anger about the misaligned distance meter. I talked to one of the scientists of the photo department who took 15 minutes for me (something very unusual here). In the end, I will send my body and lens to Zeiss and will instantly get a new body and lens out of their stock. They need about one day to check the new body/lens, since they want to be sure, that I get a perfect one this time. The misaligned body will be checked and sent to Cosina to give feedback about their QC.
Besides this, he told me, that the online-dealer I got my ZI from deals with grey-market models (although he explicitly marks on his homepage, that his models are *not* grey-market ones). As far as I know, buying grey-market equipment normally leads to loss of warranty (here in Germany), but Zeiss will replace nevertheless, he said.

Well, first I was a bit angry to have bought a bad copy, but since I already love my Zeiss Ikon so much, I now mainly are happy about the great service. 😉

 

[Nachkebia]

Well, I better check mine 🙂 congrats for your good service 🙂