Strange focusing problem between 2 cameras and the same lens, look please.. examples

Leica All Day

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Hello Everybody,

I did a photo shoot the other day and noticed that almost every photo (2 rolls) that I shot with my 35mm 1.2 (V1) was out of focus. I only used 2 lenses during this shoot, the other lens was my 90mm Summicron.....

There are some very "interesting" things that I should mention that might help solve this problem. I had Youxin replace the back film plate on my M2 because it had a dent in it, now the back film plate looks brand new.... I used the M2 ( did not use my M6 at all) for the 1st time for this photo shoot with the "new back film plate" and I got "out of focus results"......

Yesterday once I got the scans back, I decided to do a test to see what was happening.... I did a test using my M6ttl and my M2 and the results are different......The lens is sharp at 1.2 on my M6ttl and a little off on my M2 at 1.2......

here are some examples

M6 with a marker
8127375876_4203bd6c74_b.jpg
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M2 with a marker



While I was testing this, I thought that a marker might not be the best way to test this, so I changed to a pen......so here are some examples from a pen

M6 with pen



M2 with pen



All of the above images were shot at 1.2 and at the closest focusing distance (.7).......you might have to darken the contrast on the "pen" shots because they are a little difficult to tell (bad metering on my part)....

and here are some out of focus shots from the shoot

35mm 1.2






Now here is something strange....the next 2 shots were shot with my 90mm summicron and they appear to be sharp (but they were not shot at f2)







and here is an example from my M6ttl with my 35mm 1.2 (shot at 1.2) taken about 2 weeks ago, so I know the lens is sharp at 1.2.....




I am going to Laos tomorrow for a 7 day photo trip, I plan on traveling along the Mekong River and taking photos.....I usually bring 2 bodies on these trips (M6ttl/M2) but now I am going to bring my M3 instead of the M2.....

A couple of questions, what the heck should I do about this once I get back from Laos...I plan on doing some tests with the M2 using different lenses and such but I am curious.... Does anyone think the new back film plate on my M2 is not set properly and causing my photos to be out of focus? Does anyone have some suggestions that I should try when I get back from my trip.....

Thanks in advance....

cheers, michael
 
You should make friends with this:
http://focustestchart.com/chart.html
This is my most photographed subject, haha...
Print this page, and apply the technique to all the combinations of lenses and cameras (and focus screens) you own, including SLR and DSLR - you will be surprised... On average, 35% of combinations are out of alignement.
 
You should make friends with this:
http://focustestchart.com/chart.html
This is my most photographed subject, haha...
Print this page, and apply the technique to all the combinations of lenses and cameras (and focus screens) you own, including SLR and DSLR - you will be surprised... On average, 35% of combinations are out of alignement.


Ok, Thanks.....I had no idea that
"On average, 35% of combinations are out of alignment."

Cheers, Michael
 
Michael,
I am just testing an M4 for focus after I had a few blurred shots.
This is what I do, since I don't have a calibrated apparatus to check it:

I put a ruler in front of the camera, at 45 degrees, and draw a small point on it. I place the target (the point) at about .9 or 1m. Then I focus on the point, and shoot the lens at full aperture.
Now, in theory, you should clearly see on the image where is the range in focus, and if everything is ok, the dot should be reasonably inside the field.
The thing is the RF focusing method, as precise as it is, still have its limitations (and don't forget our eyes) so I repeat the test several time, each time focusing from a different direction (from the far distance to the close, and vice versa). If I test a camera, I'll do this with several lenses, if possible, lenses that are known to be good.
With a 35mm f/1.2, you have no room for error, and the smallest distance discrepancy throws your focus off.
 
Michael,
I am just testing an M4 for focus after I had a few blurred shots.
This is what I do, since I don't have a calibrated apparatus to check it:

I put a ruler in front of the camera, at 45 degrees, and draw a small point on it. I place the target (the point) at about .9 or 1m. Then I focus on the point, and shoot the lens at full aperture.
Now, in theory, you should clearly see on the image where is the range in focus, and if everything is ok, the dot should be reasonably inside the field.
The thing is the RF focusing method, as precise as it is, still have its limitations (and don't forget our eyes) so I repeat the test several time, each time focusing from a different direction (from the far distance to the close, and vice versa). If I test a camera, I'll do this with several lenses, if possible, lenses that are known to be good.
With a 35mm f/1.2, you have no room for error, and the smallest distance discrepancy throws your focus off.

Thanks a lot, I will try that when I get back from Laos...... So far, my m6ttl and 35mm 1.2 wide open have been good.....It's the M2 I am worried about.....but I will do a complete test when I get back and see what's going on....

thanks for that tip....

cheers, michael
 
Sure,

and this is what I see on my front focusing M4...:bang:
 

Attachments

  • test M4 01 rff.jpg
    test M4 01 rff.jpg
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michael,

i have problem with focus accuracy between lens and bodies.
what i realise is that not all lens and bodies are calibrated,
also, whether you turn the lens from infinity to focus or from
minimum distance to focus affect the focusing areas.

So for example, at widest aperture f3.5 on the GW690, to
get focus accuracy, i turn from Minimum distance of 1m to
the object of focus. If I do so from Infinity, it is always a little
off.

I sort of gave up a while ago trying to get all my lenses to be
accurate with all my m bodies. my m4, m2 and R-D1 all
exhibit issues with certain lenses, so I only pair them
with specific lens, when I determine which way is more accurate.

eg. My M4 is paired with a Collapsible cron which front focuses on
other m-bodies, my M2 is fixed permanently to a 35mm wide-angled lens
etc

raytoei
 
With a 35mm f/1.2, you have no room for error, and the smallest distance discrepancy throws your focus off.

Focusing a 35/1.2 wide open shouldn't be that critical, really. At 0.70 cm to 200 cm or so (I didn't check for further distances), you get about the same amount of DOF as a 50mm f2.5 - f2.8 lens shot wide open.

I'm not sure what's wrong with Michael's 35/1.2 and M2 combo, but a new pressure plate shouldn't change anything. Did anything else get adjusted while the camera was in for the new pressure plate, Michael?
 
Ray
About the direction of focusing: I'm testing the gear for that: I repeat the experiment alternating the directions.
any consistent problem in one direction or an other would mean either a slack in the lens mechanics or in the camera RF mechanism (or something impeding the movement in one direction)
My experience is that Leicas allows for enough precision for the actual focus point to be inside the field of focus for the regular lenses that I use (50 f/2 and in the past 1.4, or 90mm f/2.8), even at minimal distances.
 
Jon
As far as I understand these issues, we are talking depth of focus, not depth of field.
The movement necessary for a wide angle lens to adapt for a given change in focus in front of the lens is much smaller than for long lenses.
As a result, the same error in dimensions is much more critical with a wide than with a long lens.
 
Wow, now I am confused......in over 10 years of using Leicas' I have never had any problems with lenses not focusing properly on any of the 3 bodies that I own (m6ttl/m2/m3) and all of this is very new news to me.......I use my m6ttl 90% of the time and just have/use the other bodies as back ups......

And to answer your question Jon, no, Youxin did not do anything else to the camera, due to the fact that I just sent him the back door, I did not send him the camera.....

As of now, I am happy/confident that my 35mm 1.2 is working well on my M6ttl and that is what I will be using most of the time.....I am also bringing my 28mm Elmarit which is working well on my M6ttl too because I just used it last week and the results are fine......I'm going to bring along my 15mm vc, 50mm rigid and 90mm summicron as well and just try to use my M6ttl the whole time ( I usually only work with one body anyways)

when I get back from Laos, then I will do some tests with my M2 and see what's up.....

Thanks everybody for your replies, I appreciate them.....

cheers, michael
 
Michael,

Just swap back doors (M2 and M3) and see what happens.

Have a safe trip,
Robert

Thats's a great idea BUT.......

That is what I did the whole time while I was in the states, but I can't remember ever using my M2 and 35mm at 1.2 and seeing the results and I seriously doubt if I go back through all the photos that I took I could remember what camera I used......

If I had thought of that earlier today or yesterday, I would of switched the back doors and shot a roll and got it developed at a one hour place...but I didn't think of it.....and the fact that I am leaving tomorrow does not give me sufficient time to test out that set, so as of now, the M3 is coming with me to Laos as a back up and if something happens to my m6ttl (bad Leica luck) I will just use my m3 and the lenses that I have and hope for the best.........

ok, I just thought about it some more.......I changed my mind....I am going to switch the back doors due to the fact that it can't be any worse than what it is now, so I am going to bring the M2 with the M3 back door and just hope I don't have to use it......I just hope my M6ttl holds up well throughout the trip and I never have to use my 2nd body.......thanks a lot for that idea, I am going to go with it....

cheers, michael
 
Jon
As far as I understand these issues, we are talking depth of focus, not depth of field.

I understand, but cannot see how the depth of focus can change just by switching the back door. All the back door does is press the film against the film rails. The distance from the mount to the film rails will determine the depth of focus. But strange things do happen...

Anyway, so what happened Micheal? Was the culprit the new back door?
 
Hi Jon, I switched the back door and just got back to Bangkok.....I only shot one roll with the M2 with the M3 back door......I just dropped the film off at the lab....but the results won't show anything because I shot 99% of my photos with my m6ttl..... I am off to the beach now for a couple of days....when I get back to BKK on Monday I will do a complete test and see what the problem is....I'll post the results once I get everything shot and developed....

cheers, michael
 
Michael,

I recognize that girl with the tattoo on her leg.

Care to rendezvous in Vũng Tàu this December ?

George

bobo.jpg

Hi George, do I know you? ...I only know one George from the time when I lived in Vietnam ....I don't think you know this girl , but then again it's a " small" world so perhaps you do know her.....

As far as December goes, I'll be in Myanmar....

Cheers, michael
 
Hi Michael,

I spoke (wrote) too soon. It's a remarkable resemblance (mistake) of identity on my part.

No, we've never met although maybe if you're in Vietnam we can. I travel in a speedy manner throughout the region. On rare occasion I visit Mueang Ratchaburi but my time is limited there.

I have no film camera photo friends in Southeast Asia. Just trying to hookup with folks with a common interest.

My interest in visiting Myanmar was squelched by my company. Don't know why but it was deemed prohibitive.

Best,
George
 
Michael,

OT: Where do you get your dental work done ? Thailand, Prague, etc. ? I need an extraction and a crown. The dentists here in the states are dollar whores whose works are deplorable. Since your teeth appear to be in order I thought I'd ask.

Please PM me if you'd rather not post here.

Thanks,
George
 
Michael,

OT: Where do you get your dental work done ? Thailand, Prague, etc. ? I need an extraction and a crown. The dentists here in the states are dollar whores whose works are deplorable. Since your teeth appear to be in order I thought I'd ask.

Please PM me if you'd rather not post here.

Thanks,
George


Haha, this must be the first post regarding dental work on RFF, but I'll answer in the open rather than a PM, due to the fact that others who visit Thailand can maybe benifit from my response.

Thailand is known as a hub as "medical tourism" and it is a huge industry out here....there are fantastic hospitals and dentists in Bangkok that cost much less than they do back in the U.S.

When my American friends visit me, they usually get dental work done or visit a hospital for one reason or another...

I'm lucky, I've got very good insurance out here and when I had to get a cyst removed from my eye lid, the 500 USD operation costed me about 15 USD.

That said, there are different levels (quality) of medical care out here, but it's all cheaper than what you would find back in the U.S.

Cheers, michael
 
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