before sending my ZI for RF alignment

[Assaf]

My ZI is going on a home trip to Japan, in order to get its RF aligned. The previous owner is doing me a big favor and helps me with it.

I wanted to know if it makes sense to send one of the lenses with it. Will the adjustment be any better this way?
I prefer keeping the lenses at home. There's also a chance I use them on other cameras at the time the ZI is away (it might take 4 to 6 weeks....).

So, what do you say? Is there any advantage at all to send the lenses?
BTW, I think this question was asked before, but how often does the RF go out of alignment in this camera?

Thanks
Assaf

 

[George S.]

I would worry too much that they would return your camera without the lens! " Sir, you say you also sent us a lens???" It can be properly adjusted without one of your lenses also taking the trip.

 

[thomasw_]

No way. It is bad enough that you have to send the ZI away because the RF alignment is whacky; they do not need your lens to fix the alignment. Do not a chance something may go amiss with the lens. Save yourself the extra shipping costs and keep the lens with you.

 

[Assaf]

Thanks guys,
that's what I wanted to hear.
I'd like to hear other opinions if you think differently

(and how long do you think I'll have to wait before the next alignment...)

cheers
Assaf

 

[jonmanjiro]

Hi Assaf, as the previous owner of this camera and the one who will handle things on this end regarding the alignment, I'm glad you posted about this as I'm also very interested to hear the opinions of others (also, I would actually prefer that you don't send me any lenses as that's more stuff I have to take responsibility for 😉)

Allow me to add the information below (as I understand it) to Assaf's first post above so others can offer opinions with a little more knowledge of the situation. The situation as I understand it is:

- the actual focus point at maximum aperture with a Zeiss Biogon 35/2 when focusing on a target 70cm away (minimum focus) is within the DOF, but the DOF is distributed unevenly toward the rear (total DOF at 70cm and f2 is 4.56cm)

- the actual focus point at maximum aperture with a Zeiss Planar 50/2 when focusing on a target 70cm away (minimum focus) is within the DOF, but the DOF is distributed unevenly toward the rear (total DOF at 70cm and f2 is 2.05cm)

- the actual focus point at maximum aperture with a Hexanon M 90/2.8 when focusing on a target 100cm away (minimum focus) is outside the DOF a few cm to the rear (total DOF at 100cm and f2.8 is 1.91cm)

Judging from these results, it appears the camera is backfocusing slightly (and maybe the Hexanon 90/2.8 as well?), though not to the point where the focus point with a 50mm f2 lens or wider will be outside the DOF.

So it sounds like adjustment fine tuning, rather than misalignment correction, is required. In this kind of situation, the problem could be with either the camera or the lens, or most likely a combination of both.

It's my understanding that to ensure perfect focusing accuracy in a situation like this, the best bet is to calibrate both the body and lenses to work correctly with each other. This is especially important with fast and/or long lenses where focusing differences are easy to see, and especially obvious with something like an M8 as you can easily test each lens. This is the reason why you hear of guys shipping their whole M8 kit off to DAG for focus alignment fine-tuning.

As such, I suspect that to get the results you're looking for, the best option may be to get your lenses and ZI body adjusted to match each other.

 

[payasam]

Jonmanjiro, with all lenses there is always more depth of field behind the point of focus than in front of it. Nothing wrong there. You are probably right about setting the body and the 90mm together: though it will be necessary to make sure that the Biogon and the Planar do not suffer when that is done.

 

[Assaf]

Jonmanjiro, with all lenses there is always more depth of field behind the point of focus than in front of it. Nothing wrong there. You are probably right about setting the body and the 90mm together: though it will be necessary to make sure that the Biogon and the Planar do not suffer when that is done.

Hi payasam, you're right, of course about the DOF. However this is not the issue with my lenses - for 35mm and 50mm the object on which I focus is on the border of the DOF region, instead of being in 1/3 of it. It's annoying because wide open the pictures are not out of focus, only a bit soft.

Jonmanjiro, I really hope it's OK with you that I raised the issue in the forum (and many thank for your kind help, of course).

It will take me a few days to send the camera, until then, any comments would be welcome.

Cheers
Assaf

 

[payasam]

Assaf, I don't know how critical we should be. I have been grumbling that the 99cm plane is sharp when my M2 is focussed at 1m. Half a dozen friends -- two experienced repair people and the others old users -- have said that I should not complain about an error of 1cm at that distance. Theory is all very well, but I have to make sure that a 90mm lens focusses correctly at minimum distance.

 

[Assaf]

Well, the 90mm I used had a very obvious back focus. The "normal" lenses turned out to be softer than they should in wide open. In addition, the RF patch doesn't align at infinity.

These things are minor now, because I don't have a 90mm lens, only normal lense. However, the point it (and I try reminding it to myself) that I don't want the camera to be an issue. There are plenty of ways in which I can be responsible to messing up a picture, I don't want to give the camera additionla ways to do so.

 

[willie_901]

Nikonwebmaster is certainly correct. I too am puzzled by those who expect rangefinders to focus as well as SLR/DSLRs.

Rangefinders are not SLR/DSLRs. Rangefinder cameras have strengths and weaknesses. One of their weaknesses is focus accuracy near the minimum focus distance and the other is accuracy of the frame lines.

If you want to take photographs using your lens' minimum focus distances (or any lens-to-subject distance less than 2 meters (~6 feet), the right tool for the job is a SLR/DSLR. DSLRs with live view are particularly good at this.

Also Zeiss told me not to send lenses with my Zeiss Ikon ZM. They test/adjust the lens cam as part of the process.

 

[notraces]

I don't get it -- either the rangefinder is out of alignment - or it's not. The issues described regarding focus point and DOF have squat to do with RF alignment. Take your camera outside -- find a tower or some other object a mile or so away - focus on it with your camera -- make sure the RF image aligns properly - no vertical or horizontal mis-alignment -- If you get a nice snappy image with no alignment issues - then, you're good to go.

As for the rest of the lens / focus issues -- I say get out there and take some photographs and stop obsessing about such nonsense.

 

[mfogiel]

I have sent my ZI to Zeiss without the lens, as I use Zeiss lenses on it mainly in any case... As for the focusing error... well a 90/2.8 lens should be able to focus decently even close up, so it should be checked, but you should be aware, that often the problem can be caused by an uneven eye placement in the VF, and this becomes more problematic when you use glasses... As to the frequency of adjustment - well , it really depends on how many bangs you will deliver... Get a camera half case to reduce the problem... Finally, I like to use my FM3A with the 85/1.4 Planar or 100/2 Makro Planar for close portraits, but the focusing is no less tricky with an SLR - I like to set the distance on the lens and basculate back and forh with the body to get the focus right, but it is always a marginal game...

 

[Assaf]

I don't get it -- either the rangefinder is out of alignment - or it's not. The issues described regarding focus point and DOF have squat to do with RF alignment. Take your camera outside -- find a tower or some other object a mile or so away - focus on it with your camera -- make sure the RF image aligns properly - no vertical or horizontal mis-alignment -- If you get a nice snappy image with no alignment issues - then, you're good to go.

As for the rest of the lens / focus issues -- I say get out there and take some photographs and stop obsessing about such nonsense.

mfogiel, I was waiting especially for you comment, thank you for giving it.

As I wrote, the RF doesn't align at infinity. So certainly, there's an adjustment problem. In 90mm lenses the object gets out of focus wide open, in 35mm and 50mm it's softer than it should be. I used to use the same 50/2 on an M6. The focus at minimum distance was dead on, so it's definitely not an RF vs SLR issue.

The reason for which I opened this thread was to be advised whether to send the lenses (that I can use on other cameras at the time the camera is away) or not. I didn't open the thread in order to consult whether there is a problem or there isn't - I know there is a problem, and I want it to be fixed.

For this reason, I find comments such as "use an SLR instead" or "your camera is fine, go out and take some pictures" (I do it anyway, and I'll do it with other cameras while the ZI is away) irrelevant.

Anyway, thank you for answers and have a nice day all of you.
I think I got answers to my original question and that this thread can be closed.

 

[jonmanjiro]

Hi Assaf, thought you might find this semi-related thread interesting (apologies if you've already seen it). Jon

Focussing behind where RF indicates focus