rlouzan
Well-known
The chart is just way too small to fill the frame at 1m, but at 0,75/0,50 cm ... that's another story. Try it and see!
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Ranchu
Veteran
Ok. I'm kind of on the fence about this, other than feeling bad about it. On the one hand, the OP is doing what I'd do to see if there's a focusing problem, know's what he/she's doing imo. On the other, there are a lot of variables and chances for error, not least of which is whether the Biogon has focus shift as designed that could account for this. ferider's side by side pics look fine to me. On the third hand, the OP's mid distance pics don't. On the fourth hand, there's the parallax thing, which I'd appreciate more info about, if anyone wants to say. The lens should be sent to be checked/tuned up, imo. From what I've seen, it's a very good lens.
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brbo
Well-known
> As for the chart ,it's not easy to take a picture of a sheet of A4 paper at 1m with a RF - just that.
I disagree. That sheet of paper with a black line in the middle is the easiest target to focus on. Even if it was 5x smaller.
> The chart is just way too small to fill the frame at 1m, but at 0,75/0,50 cm ... that's another story. Try it and see!
No much point in trying to fill my viewfinder with the target at 0.5m if I can't focus that close with my lens or body, is it? And I still don't know what's that got to do with anything...
> Look, I don't think the seller acted in bad faith.
I've said it many times now. I can understand that he thought lens was OK. He did NOTHING to help me get what I paid for, though. I paid for a 'perfect lens with small paint wear'. He deleted the ad (or ads get deleted automatically here?) but I can PM you link to Google cached page with the original ad if you want.
> I bet the lens became defective in shipping ,and the carrier should be responsible for the repair bill.
I think that is a VERY VERY risky bet. But, still, how would I handle that? I have a perfectly shaped outer packaging box here and like new original Zeiss Biogon box with it's styrofoam intact. Who do you think should deal with the postal service or services (international delivery)? Seller or buyer?
> On the other, there are a lot of variables and chances for error, not least of which is whether the Biogon has focus shift as designed that could account for this. ferider's side by side pics look fine to me.
Biogon does not shift focus by design. Side by side pics are not fine. It's just that crappy film makes differences not so obvious. Targets at 3m are not fine. Real pics at 10m are not fine.
But what I wanted to say is, thanks Roland for helping me locate the spanner ring and special thanks to all who recommended repairers with whom they've had good experience.
I disagree. That sheet of paper with a black line in the middle is the easiest target to focus on. Even if it was 5x smaller.
> The chart is just way too small to fill the frame at 1m, but at 0,75/0,50 cm ... that's another story. Try it and see!
No much point in trying to fill my viewfinder with the target at 0.5m if I can't focus that close with my lens or body, is it? And I still don't know what's that got to do with anything...
> Look, I don't think the seller acted in bad faith.
I've said it many times now. I can understand that he thought lens was OK. He did NOTHING to help me get what I paid for, though. I paid for a 'perfect lens with small paint wear'. He deleted the ad (or ads get deleted automatically here?) but I can PM you link to Google cached page with the original ad if you want.
> I bet the lens became defective in shipping ,and the carrier should be responsible for the repair bill.
I think that is a VERY VERY risky bet. But, still, how would I handle that? I have a perfectly shaped outer packaging box here and like new original Zeiss Biogon box with it's styrofoam intact. Who do you think should deal with the postal service or services (international delivery)? Seller or buyer?
> On the other, there are a lot of variables and chances for error, not least of which is whether the Biogon has focus shift as designed that could account for this. ferider's side by side pics look fine to me.
Biogon does not shift focus by design. Side by side pics are not fine. It's just that crappy film makes differences not so obvious. Targets at 3m are not fine. Real pics at 10m are not fine.
But what I wanted to say is, thanks Roland for helping me locate the spanner ring and special thanks to all who recommended repairers with whom they've had good experience.
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Ranchu
Veteran
Fair enough, you're the one who did the tests. I guess I'm trying to be optimistic for your sake, a habit that can be annoying. Good luck!
elmer3.5
Well-known
Miss focus
Miss focus
Hi, in my experience almost 80% of the lens i´ve owned had some focusing issues.
Some of them were brand new:
Rollei sonnar hft 40/2.8 back focus about 3 inches
Biogon 35/f2 back focus about 2 inches
Biogon 28/2.8 front focus 1 inch
Elmar 3.5 cm front focus 4 inches
Jupiter 12
Canon 35mm f1.8
Jupiter 8, front focus can´t recall amount...
Not to mention fast lenses like the canon 50/1.2 but that´s another story.
I don´t think seller even know they´re off focus , so early i decided to fix the problem myself, because here, are no technicians that can help me.
RF can be also troublesome i calibrate them at night using red lights on antennas set about 2.5 miles away from home.
even at that distance setting infinty can be hazardous, a slight difference may mean some shifting at 1 metre.
I can make these jobs because of a digital RF camera, with film is virtually impossible to remember any bad setting or miss alignment on the lens or on the RF of your cam.
And you must take into consideration that people never have the same eyesight capabilities...
So i wouldn´t be too annoyed cos it will happen again in the future, try to get some refund to set it to proper focus or best is to know how to fix the problem.
Bye!
Miss focus
Hi, in my experience almost 80% of the lens i´ve owned had some focusing issues.
Some of them were brand new:
Rollei sonnar hft 40/2.8 back focus about 3 inches
Biogon 35/f2 back focus about 2 inches
Biogon 28/2.8 front focus 1 inch
Elmar 3.5 cm front focus 4 inches
Jupiter 12
Canon 35mm f1.8
Jupiter 8, front focus can´t recall amount...
Not to mention fast lenses like the canon 50/1.2 but that´s another story.
I don´t think seller even know they´re off focus , so early i decided to fix the problem myself, because here, are no technicians that can help me.
RF can be also troublesome i calibrate them at night using red lights on antennas set about 2.5 miles away from home.
even at that distance setting infinty can be hazardous, a slight difference may mean some shifting at 1 metre.
I can make these jobs because of a digital RF camera, with film is virtually impossible to remember any bad setting or miss alignment on the lens or on the RF of your cam.
And you must take into consideration that people never have the same eyesight capabilities...
So i wouldn´t be too annoyed cos it will happen again in the future, try to get some refund to set it to proper focus or best is to know how to fix the problem.
Bye!
rlouzan
Well-known
Hi,
I agree with you!
Too many variables:
Poor eyesight, camera RF out of adjustment, focuss shift, parallax error, MF/LF film not completely flat,f/stop, low quality filters, fluorite lens elements, loose lens cell, problem with camera register distance (lens to film distance) ...
AND I'M TALKING ABOUT ALL CAMERA BODIES AND LENSES!
I agree with you!
Too many variables:
Poor eyesight, camera RF out of adjustment, focuss shift, parallax error, MF/LF film not completely flat,f/stop, low quality filters, fluorite lens elements, loose lens cell, problem with camera register distance (lens to film distance) ...
AND I'M TALKING ABOUT ALL CAMERA BODIES AND LENSES!
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brbo
Well-known
> Hi, in my experience almost 80% of the lens i´ve owned had some focusing issues.
That's an insane number. I had focusing issues with 1 (this) RF lens out of 5 I've had or tried (non was purchased new) and 1 SLR lens out of some 15.
If this is the norm in RF (and I'm almost positive it is not) then I should probably just shot all my 135 film on 50 EUR Nikon F80 and 200 EUR Nikkor 35/2. Cause, if my lens is indeed within specs as some think according to my posted shots, Nikkor is vastly superior to Biogon (except for distortion).
Having to have almost every lens matched to specific body means that either:
1. it's the body
2. none of the manufacturers follow the specs
3. RF system is flawed
I think there are too many happy RF users that can shoot their lenses with focus landing where they place it, so I doubt it's 2 or 3.
That's an insane number. I had focusing issues with 1 (this) RF lens out of 5 I've had or tried (non was purchased new) and 1 SLR lens out of some 15.
If this is the norm in RF (and I'm almost positive it is not) then I should probably just shot all my 135 film on 50 EUR Nikon F80 and 200 EUR Nikkor 35/2. Cause, if my lens is indeed within specs as some think according to my posted shots, Nikkor is vastly superior to Biogon (except for distortion).
Having to have almost every lens matched to specific body means that either:
1. it's the body
2. none of the manufacturers follow the specs
3. RF system is flawed
I think there are too many happy RF users that can shoot their lenses with focus landing where they place it, so I doubt it's 2 or 3.
sebastel
coarse art umbrascriptor
these two statements contradict:
if the spanner ring is tight, there is no wobble.
if there is wobble, the spanner ring is not tight.
concerning focus ring play: the zeiss lenses i know have no noticeable play in direction of the optical axis. only one lens (the oldes and most worn one) has a little bit of play in the perpendicular direction of the optical axis - nothing interfering with the focussing of the lens.
maybe your lens is not collimated exactly?
cheers,
s.
if the spanner ring is tight, there is no wobble.
if there is wobble, the spanner ring is not tight.
concerning focus ring play: the zeiss lenses i know have no noticeable play in direction of the optical axis. only one lens (the oldes and most worn one) has a little bit of play in the perpendicular direction of the optical axis - nothing interfering with the focussing of the lens.
maybe your lens is not collimated exactly?
cheers,
s.
Digital rangefinders are particularly picky about focus calibration, given the high resolution capability and mechanical nature of RF focusing. It's been my experience with two M8 bodies and one M9 that the bodies are in spec, while it's the lenses that need adjustment. Most M (and of course previous LTM) lenses were made with the expectation of use on film bodies where things aren't quite as critical.
One hopes lenses designed and made since the advent of the DRF have been kept to tighter tolerances. I've sent about a dozen lenses to DAG for 6-bit coding and/or focus check/calibration. All but two lenses needed adjustment, though for the focus-shifting C-Sonnar and 35 Summilux ASPH it was mostly a matter of optimizing at what aperture the focus should be exact. As I recall the 50 Planar-ZM needed no adjustment, and no adjustment could be made with the 1.4/35 Nokton, but others including 18mm Distagon, 21 C-Biogon, 25 Biogon, and both 35mm ZM lenses did, as did Leica 21 ASPH, 28 & 35 Summicrons. DAG just brings the lenses into correct specification on his test bench after having the coding done; I've not sent him a body to calibrate a lens to.
FWIW, SLR cameras are at least as troubled by focus shift as RFs, since generally focus is through the wide-open lens, whereas the actual shot is at a smaller aperture. If the lens has no focus shift and is simply out of spec, this shouldn't trouble TTL focusing... though AF issues are troublesome enough that some dSLRs now allow tweaking the AF settings for particular lenses.
There's really no getting away from it, IMO, without thorough checking and possible adjustments to spec.
One hopes lenses designed and made since the advent of the DRF have been kept to tighter tolerances. I've sent about a dozen lenses to DAG for 6-bit coding and/or focus check/calibration. All but two lenses needed adjustment, though for the focus-shifting C-Sonnar and 35 Summilux ASPH it was mostly a matter of optimizing at what aperture the focus should be exact. As I recall the 50 Planar-ZM needed no adjustment, and no adjustment could be made with the 1.4/35 Nokton, but others including 18mm Distagon, 21 C-Biogon, 25 Biogon, and both 35mm ZM lenses did, as did Leica 21 ASPH, 28 & 35 Summicrons. DAG just brings the lenses into correct specification on his test bench after having the coding done; I've not sent him a body to calibrate a lens to.
FWIW, SLR cameras are at least as troubled by focus shift as RFs, since generally focus is through the wide-open lens, whereas the actual shot is at a smaller aperture. If the lens has no focus shift and is simply out of spec, this shouldn't trouble TTL focusing... though AF issues are troublesome enough that some dSLRs now allow tweaking the AF settings for particular lenses.
There's really no getting away from it, IMO, without thorough checking and possible adjustments to spec.
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brbo
Well-known
Hm... How tight is tight? First I tried to unscrew the ring (with not much force). The ring wouldn't move. Then I tired to tighten it with a bit more power. Wouldn't budge at all. Now, I was relatively gentle as I didn't know if for tightening the spanner ring you need to fixate the ring underneath it first so that the force doesn't get distributed to some other parts of the lens... Btw, Roland in his PM to me said that the other possible cause for the wobble are loosened screws inside the lens.
As for the focus ring play, mine is the same as yours. Annoying yes, but it doesn't seem to affect focusing.
Wouldn't rangefinder patch be out of alignment at infinity if the lens was not collimated correctly? I thought this is the way to check for this and I already stated that the patch is perfectly aligned at infinity. What else needs to be checked? I won't be able to check for it now as I have the lens packaged and ready for shipment to Zeiss, but I would still like to know...
Yes, I've read about Leica's film vs. digital body flange distance discrepancies. Did you had to have all your lenses adjusted when you moved between M8 #1, M8 #2 and M9?! Or just once when you went digital?
rlouzan
Well-known
sebastel
coarse art umbrascriptor
being gentle is a good idea.
from your description, the spanner ring was not loose.
as far as i know the mechanical construction of the ZM lenses, i suppose this to be less likely. the optical block is quite tightly assembled ...
no, as rlouzan already stated.
the focussing block agitates the rangefinder lever on the inner side, and the optical block on the outer side (with different ratio respectively, in all lenses other than 50mm).
you may remove the optical block completely, and the focusing block would still push the rangefinder lever in perfect alignment with the distance scale.
collimation is the process to set the optical block into the correct distance to the basis plane of the focusing block. usually, this is done by adding or removing thin shims (flat rings of defined thickness).
your lens seems to need collimation. if i was you, i'd send it to zeiss.
regards,
s.
Wobble, maybe not...but front focus maybe no? Wobble is a way of life with the Zeiss stuff...
brbo
Well-known
Yeah, I guess so. I did my homework though and knew some Zeiss lenses wobble. Buying a 'perfect' used lens vs. new seemed like a good idea at that time (even though it wasn't that much cheaper than a new one). I even liked the fact that it had some paint loss as that indicated that it was frequently used yet still perfect in mechanics and optics.
Thanks for clarification on that. I thought that collimation of the lens only referred to making sure the lens would push the body rangefinder cam into correct position.
Lens is on its way to Zeiss. Will report back when I hear from them.
brbo
Well-known
Where did I say those two things are connected?!
Just the once, over time. I'm speculating that the digital M is held to tighter tolerances than the film bodies... The specification is the same.
sebastel
coarse art umbrascriptor
well ...
since the infamous wobble is due to loose spanner rings, front focusing _may_ happen at the same time. more precisely: if the spanner ring is so loose that the optical block has moved outward from its assumed 'zero' position.
it does not need to be related, but it may be.
jawarden
Well-known
It's clear from your first post that you won't be selling this lens with a clear conscience in it's present condition (good for you), so you might as well send it to Zeiss and have the confidence that the job will be done correctly. Hopefully the repair/adjustments will help you enjoy the lens, despite the bad memory of the purchase.
When properly sorted, this is a fine lens. I hope you enjoy it!
When properly sorted, this is a fine lens. I hope you enjoy it!
brbo
Well-known
Just to report back, I got the diagnosis report from Zeiss Germany.
As always, there is good and bad news. The good news is I'm not blind and my RF body is most probably just fine.
The bad news:
"Diagnosis:
Play in focusing ring. Flange focal distance and cam height out of tolerance. Particles inside.
Necessary service:
Disassembling of lens. Complete overhaul of focusing helicoid. Cleaning inside. Adjusting of flange focal distance and cam height. Performance and function check, test pictures.
The costs for the service mentioned above will be
190,- Euro (net price)"
But I expected something like this so I'm just glad that the lens will probably stop taking out of focus pictures after I get it back from Zeiss.
As always, there is good and bad news. The good news is I'm not blind and my RF body is most probably just fine.
The bad news:
"Diagnosis:
Play in focusing ring. Flange focal distance and cam height out of tolerance. Particles inside.
Necessary service:
Disassembling of lens. Complete overhaul of focusing helicoid. Cleaning inside. Adjusting of flange focal distance and cam height. Performance and function check, test pictures.
The costs for the service mentioned above will be
190,- Euro (net price)"
But I expected something like this so I'm just glad that the lens will probably stop taking out of focus pictures after I get it back from Zeiss.
joeswe
Well-known
So,
now that the diagnosis is official, it would seem only fair to me if the seller and the buyer would each bear half of the repair costs. It is most probable that something inside of the lens loosened up during transport because of sustained vibrations or whatever. Given the circumstances (undamaged packaging, "hidden" nature of the damage etc) trying to get compensation from the carrier is a futile exercise IMO. This definitely shouldn't happen with a perfectly assembled lens, but it doesn't come as much of a surprise after my personal experience with the assembly quality of Cosina.
John
now that the diagnosis is official, it would seem only fair to me if the seller and the buyer would each bear half of the repair costs. It is most probable that something inside of the lens loosened up during transport because of sustained vibrations or whatever. Given the circumstances (undamaged packaging, "hidden" nature of the damage etc) trying to get compensation from the carrier is a futile exercise IMO. This definitely shouldn't happen with a perfectly assembled lens, but it doesn't come as much of a surprise after my personal experience with the assembly quality of Cosina.
John