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21mm Biogon on M8,


mtwo

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I just bought a 21mm lens, the Zeiss, since no way could I afford the Leitz version and I wanted f2.8. First, I find that it is possible to see the 21mm field of view by shifting your eye to the extreme edges of the VF. An auxilary finder, if you can find a 28mm one would probably be easier but this works. Take your VF magnifier off though.

 

Secondly, I did not buy a shade for the lens. Thought I could find something which would work which would be cheaper than the $65 Popflash is charging for the hood. Strangely enough, I did. The shade which came with my 28mm F1.9 Voigtlander works just fine if you attach it to the UV/IR filter. Will not work otherwise. Stopgap, perhaps, but it works. Since the shade comes with the 28mm lens it's free, oh sure it is. If you go to buy one from Cameraquest it is almost 50 bucks. Hope this is of use to some. John

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I just bought a 21mm lens, the Zeiss, since no way could I afford the Leitz version and I wanted f2.8. First, I find that it is possible to see the 21mm field of view by shifting your eye to the extreme edges of the VF. An auxilary finder, if you can find a 28mm one would probably be easier but this works. Take your VF magnifier off though.

 

Secondly, I did not buy a shade for the lens. Thought I could find something which would work which would be cheaper than the $65 Popflash is charging for the hood. Strangely enough, I did. The shade which came with my 28mm F1.9 Voigtlander works just fine if you attach it to the UV/IR filter. Will not work otherwise. Stopgap, perhaps, but it works. Since the shade comes with the 28mm lens it's free, oh sure it is. If you go to buy one from Cameraquest it is almost 50 bucks. Hope this is of use to some. John

 

Have a question for you. I have a 21mm biogon as well. I've noticed that the front part of the lens is a little loose. By front part, I mean the hood mount ring + aperture ring. And by "a little loose", I mean about 1 mm of rotational play. I have two other Zeiss lenses - a 35mm Planar and a 50mm Planar, and have not noticed any play on these two lenses. I never noticed until recently and am wondering if it's always been there. Never any trama or accidents to the camera or lens. Can you (and anyone else who owns a 21mm Biogon) please check and see if there's ANY play whatsoever? I'm trying to decide whether I should send it in for warranty repair or not. The image quality hasn't been affected as far as I can tell (but I don't really know how I would test for a problem either).

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Like all of my Zeiss lenses - no play at all. The aperture ring & focus rings are rock solid without any play. You should have a silky smooth action with very positive clicks at 1/3rd stop intervals. Even the hood has no play at all which makes my 28 Cron feel cheaply made by comparison.

 

It sounds like something isn't right with your lens.

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Bye the way, I neglected to mention that the hood from a 40mm CV f1.4 fits a 50 Planar just fine. No filter needed and it works well. Some subsequent testing is showing me that the hood from the 28, used on the 21, may not be the answer I thought it was. I'll figure it out eventually. Help me out and do a test if you have the hardware. John

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all in all , an excellent lens!!

 

ran Cornerfix on it, with the Leica IR/UV filter

 

(warning . .full size M8 images)

 

before:

 

before Cornerfix

 

after:

 

with Cornerfix

 

 

(i didn't do any other modifications.. the removal of the vignetting made the leaf in the lower right corner hot.. would normally fix that in a final image)

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all in all , an excellent lens!!

 

ran Cornerfix on it, with the Leica IR/UV filter

 

(warning . .full size M8 images)

 

before:

 

before Cornerfix

 

after:

 

with Cornerfix

 

 

(i didn't do any other modifications.. the removal of the vignetting made the leaf in the lower right corner hot.. would normally fix that in a final image)

 

Jim

 

I am confused about how light the tonality became after cornerfix. It is so much lighter I am not very secure in assessing the results from the cornerfix itself. Is there a reason why the image is so much lighter

 

Thanks in advance for taking the time to answer my query

 

Woody Spedden

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Jim

 

I am confused about how light the tonality became after cornerfix. It is so much lighter I am not very secure in assessing the results from the cornerfix itself. Is there a reason why the image is so much lighter

 

Thanks in advance for taking the time to answer my query

 

Woody Spedden

 

 

if you crop the center of each of the images, you'll see the values are pretty close. From what i understand, cornerfix also does some remapping of the raw data (someone who's familiar with the program should step in here). this was done with a quick profile i made using available light and the expodisc. i suspect under a more controlled test, the vignetting correction might not be as great. i just took the raw output without mods from cornerfix and converted. by adjusting the image in Lightroom, i would get a much closer match in tonal values (in fact, i'll do that and post the jpg as well)

 

 

ok.. added another .. processed image (just changed tonal values) from Lightroom (source was the output from Cornerfix)

 

processed Cornerfix output

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if you crop the center of each of the images, you'll see the values are pretty close. From what i understand, cornerfix also does some remapping of the raw data (someone who's familiar with the program should step in here). this was done with a quick profile i made using available light and the expodisc. i suspect under a more controlled test, the vignetting correction might not be as great. i just took the raw output without mods from cornerfix and converted. by adjusting the image in Lightroom, i would get a much closer match in tonal values (in fact, i'll do that and post the jpg as well)

 

Jim,

 

I __strongly__ recommend against using ExpoDisc to generate profiles - ExpoDisc itself causes vignetting, so you can get some very strange results; the color correction will be ok, because ExpoDisc is color neutral, but you can get either over or under compensation of luminosity in the corners. Which is what I suspect you have.

 

Regards,

 

Sandy

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Jim,

 

I __strongly__ recommend against using ExpoDisc to generate profiles - ExpoDisc itself causes vignetting, so you can get some very strange results; the color correction will be ok, because ExpoDisc is color neutral, but you can get either over or under compensation of luminosity in the corners. Which is what I suspect you have.

 

Regards,

 

Sandy

 

Thanks! good to know.. i just started playing around with it.

 

jim

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Sandy any news or us poor mac guys

 

Guy,

 

Working on it as we speak.......unfortunately, it's turning out to be a monumental PITA, and I've had very little time the last four weeks. But the next few weeks will be far better.

 

Regards,

 

Sandy

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Have a question for you. I have a 21mm biogon as well. I've noticed that the front part of the lens is a little loose. By front part, I mean the hood mount ring + aperture ring. And by "a little loose", I mean about 1 mm of rotational play. I have two other Zeiss lenses - a 35mm Planar and a 50mm Planar, and have not noticed any play on these two lenses. I never noticed until recently and am wondering if it's always been there. Never any trama or accidents to the camera or lens. Can you (and anyone else who owns a 21mm Biogon) please check and see if there's ANY play whatsoever? I'm trying to decide whether I should send it in for warranty repair or not. The image quality hasn't been affected as far as I can tell (but I don't really know how I would test for a problem either).

 

if you take the rear lens cap off, you'll see a ring with slots for a spanner wrench. check that to see if it's loose. i've had a 21 that exhibited the same loosness, and all it needed was that to be tightened

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No looseness in my Biogon either - an extremely well-made lens, and excellent optically. Maybe just a little contrasty for ideal performance on the M8, but nothing that's not easily corrected.

 

Re: hoods, the 25/28 hood works well on the M8 and blocks less of the viewfinder than the 21 hood.

 

John Milich now offers notch cutting of Zeiss mounts for 6-bit coding. Unfortunately, the Biogon triggers the "wrong" framelines to be coded as a 21 Elmarit. A Zeiss 28mm mount works properly, and can be obtained from Zeiss Germany.

 

I tried and had zero luck getting one through Zeiss USA - they never even answered my inquiry. The German service department was very helpful, fast and courteous...

 

T

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  • 3 weeks later...
No looseness in my Biogon either - an extremely well-made lens, and excellent optically. Maybe just a little contrasty for ideal performance on the M8, but nothing that's not easily corrected.

 

Re: hoods, the 25/28 hood works well on the M8 and blocks less of the viewfinder than the 21 hood.

 

John Milich now offers notch cutting of Zeiss mounts for 6-bit coding. Unfortunately, the Biogon triggers the "wrong" framelines to be coded as a 21 Elmarit. A Zeiss 28mm mount works properly, and can be obtained from Zeiss Germany.

 

I tried and had zero luck getting one through Zeiss USA - they never even answered my inquiry. The German service department was very helpful, fast and courteous...

 

T

 

hi Tom,

Is the mount of ZM 21f2.8 easily removed? Is it "attached" to any part of the helicoid? Thanks.

mike

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Four screws only. You'll need to loosen them up by applying a SMALL drop of acetone, as they have used some kind of Locktite. Zeiss recommend "tempering the lens in an oven"which I could not find the courage to do, in fact that is scary.

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hi Tom,

Is the mount of ZM 21f2.8 easily removed? Is it "attached" to any part of the helicoid? Thanks.

mike

 

There are no connections between the mount and any other components of the lens, other than the mounting screws.

 

I had a professional repairman remove the screws, knowing about the Loctite issue and not wanting to try that myself without some experience. He had a bit of trouble with one, but nothing terrible. He did mention thinking the screws were noticeably tighter than other (non-Zeiss ZM) lenses he had worked on.

 

I now have the 28mm mount back from JM, and will be re-installing it today. Should be simple enough. One screw is located in the area of the coding notches, but it doesn't appear that it will interfere with coding.

 

T

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To coat the zeiss 21 f2.8 as a 21 aspherical summicron I had to get a little piece of white on that screw otherwise it triggered the 28 mm correction. But the lens is quite nice my only regret is when my wate comes in I will have to sell mine to pay for the wate. The 21 zeiss is just a great lens .David

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