CJZ Biotar 1.5/75 (converted to LTM)

[koji]

I have received the lens today. The optics is clean, F-stop works smoothy
I guess due to lots of oil on blaids.

Stay away from some of LTM converted Biotar 1.5/75, Andy.

On my specimen:

Mine does not work with rangefinder cameras I have, the first of all
you cannot mount on the camera due to very large LTM base, which
interferes with mount release button and/or frame change lever on Ms.

Secondary the lens is too short to focus anything on M/L mount cameras.

Thirdly the very lens has LTM thread, you require L->M42 adapter and
to M42->EOS adapter for EOS cameras, alas you cannot focus infinity!

Do you know there exists L->EOS adapter?

If it ever exists, you are able to focus infinity. So better get an Exakta
mount Biotar, you will save lots of anguish and money!!!!!

Nikon has L->F mount adapter, so I mounted the lens on Nikon camera
using this adapter, infinity is not attainable at all. Longer register distance than
Canon EF mount.

I did a quick test with EOS 5D, it is certainly not slouch but not impressed neither.


Ok, I will keep this lens for a while until I find the solution for the above
problem. Stay tuned....

I am going to Tokyo from tomorrow or the day after tomorrow, so test shots
are after coming back if I can. There are many tyhoons, tsunamis, and
angry wives around these days.

See Ya.

[Attila]

Damn it! I feel badly, due lens was my suggestion. I hope some expert in Tokio able to give you good advice.

[kds315*]

Sorry, but I don't understand Koji.

Is this the slim type Biotar or the fat type?

Is the rangefinder coupling there and are you able to focus using the rangefinder?

Does that look professionally converted or is that a do-it-yourself solution?

Would you mind posting pictures showing the conversion done?

Thanks, Klaus

P.S.: No of course there is no L-->EOS adaptor sincve that would not make ANY sense since LTM register is much shorter than EIS register

[koji]

[Spotmatic]

[koji]

Hi Attila,

Don't worry. I have understanding wife.

I now remember our departure data is Sunday Oct.11. I may be
suffering by Alzheimer's xxx.

Anyway there is always a solution or two, I like this kind of challenge.

[F16SUNSHINE]

Hi Koji
Sorry for your trouble.
I saw a picture of the lens you have in the ebay auction.
It looks like the adapter was simply attached to the original mount. Is it possible you can remove the brass adapter and find exacta or M42 underneath?

[koji]

I haven't inspect it yet, Andy.

The brass adapter was professionally made, it at least seems to me.
The base has three screws holding lens body, I will look into it.

[koji]

The back of LTM Biotar 1,5/75 >


There is a black ring/shim inside of brass base, so I can see a solution.
This has exactly 0.70 mm thickness, so I can find a thinner shim or make it.

So I can see the light now with this lens (pan intended ) and existing
adapters I have.

[trifox]

I am EXTREMELY concerned in this problem.

But I can not tell anything so far


tf

[kds315*]

[F16SUNSHINE]

I can see now by the diameter of the brass adapter why it would not fit on the M mount camera.
Out of curiousity I put my M42 1.5/75 skinny up to the M mount. It does clear the release button and frameline preview lever.
Any adapted lens would need to have this factor taken into effect.

Some of the other fast rangefinder lenses have a conical looking end on the mount side. I see this with my Hexanon 1.2/50.
The glass is just too big

The adapter here looks like an a-mount that I have with a tair 11.
If you want send me the diameter. Maybe it is a fit I could send it to you.

[koji]

What is "A-mount", Andy? Just curious, you may be right the lens came
with ZENIT L-mount rear cap. I do not think my logic is very sound.

The lens base body diameter/thickness is exactly 53.0 mm.

Somehow I can fix my problem easily now, so I can sleep well tonight.

I found ZENITH 3M mount M39x1 thread mount with 45.46 register distance.
This must be it, its register is same as M42 mount, isn't it? Now I understand
my original problem.

The seller should have said Zenith M39 mount.... uuuggghhhh

[F16SUNSHINE]

A-mount is an exchangable ring mount that some lenses have.
It looks very much like the M39 adapter you have there but not as wide.
The one I have will not work. It is only 48mm on the inside diameter.
I bet you will find a easy solution for this mount issue

[trifox]

Hi Koji -- we are sorry about this -- as you have mentioned above it's a bastard but no worries..

As you know this is not a CONVERSION of Biotar to LTM, this is SIMPLY BAD product ....
and it's NOT A PROFESSIONAL WORK....

Robert (the technician of CSO) has had a look at it and immediately knew what's on.
The lens has been simply CUT OFF (we think -- too much). It's not USABLE for LTM camera in NO WAY.
If you want us to finish it -- we can do it. The lens is still usable for conversion for LTM cameras and we have set a plan. You'll be satisfied

please, contact us on:
info@cameraserviceone.com

Please, if you have ANY LENSES SUCH AS THESE for CONVERSION --- PLEASE CONTACT US!!!

tf

[trifox]

this is just for your info

I have played with this on our site --

have a look at it -- it's a fun -- I hope I put correct registers in

http://www.cameraserviceone.com/061000-registers.php

tf

[kds315*]

Nice and helpful Stan!

I just used
http://www.graphics.cornell.edu/~westin/misc/mounts-alphabetical.html
http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html
before.

[koji]

Thank you guys, Tf and Klaus.

That HP is fun, trifox. I saved one of HP address to my fav, Klaus.

I did shoot with this lens in this way

The lens (with brass base + original shim) + M42->EF adapter + EOS_5D
and holding the lens by left hand and press to M42 adapter, lens focus to
1 m and F1.5. Moving whole thing to focus, and press button. No AF shot, Orio.
In this setting the lens go very slightly beyond inf, so this lens was intended for
Zenith M39 lens. Here is examples...

Sorry for very boring and bad shots....




Bokeh is very creamy at f1.5, sharpness is alright for at wide open.

I am going to sand M39->M42 (2 mm thick) down, and take out the shim in the lens.
The lens will be reborn as an M42 CZJ Biotar 1,5/75.

According to CZJ's serial number table for production date, this lens was made
between 1970 and 1975. This looks odd to me, the lens does not have coating?!

[kds315*]

Stan,

you have "green light" - go ahead!! It is all clear to me now.

Cheers,

[kds315*]

That lens should certainly be coated, but I am very astonished about the 1970++ production year you mentioned. Let me have the serial number and I look it up for you.

[koji]

Sorry my mistake, mine was made before 1945, like me.
SN# 2,688,189

No surprise?

[kds315*]

OK, now that fits...

[trifox]

[koji]

I may ask the modification for this lens eventually, Stan.
But not now, I want to do some experiments.

[koji]

I just bought M39->EF adapter with AF confirmation chip US$26.

Now I can shoot without worries for the time being.
Everything is alright (will be) after receiving the adapter hopefully.