Hi

Just bought this beautiful lens, but found out that i had not done proper research before
buying it, i found out that due to a 0,5mm of the back lens element it crashes with the mirror
on long distances with my 5D MKII (it works ok with live view but that's not the way i like to work)
(I use it with the Haoda Electronic M42 Adapter if it matters)

So my question is, is it possible to "modify" this lens for "normal" use with my camera?

Thanks guys...

Supposedly this is quite a nice lens.

Can you post a picture of the back straight-on, I have a theory that you migh be able to file the rear element retaining/protection ring down and thus reclaim your 0.5mm

Empire wrote:
Supposedly this is quite a nice lens.

Can you post a picture of the back straight-on, I have a theory that you migh be able to file the rear element retaining/protection ring down and thus reclaim your 0.5mm

Here you go...

Yes, there is plenty of metal there to file down!

You only need to remove metal from the top half of the rear end as that is where the mirror will be catching. This may or may not include the rear element retaining ring (the inner ring with the notches on it).

Opinions vary as to what is the best way of achieving your end result but whatever method of removing the metal you choose, make sure that NO metal filings get inside the back of the lens. To this end I recommend removing the rear element retaining ring (the one with the four notches) and filing it on its own first. just make sure you mark which bit needs filing or you may have to do it twice

By the looks of it you will also need to file the other black ring which is outside of that notched ring. In this case you will need to fill all the gaps in the back of the lens with tissue paper and sticky tapeto make sure nothing can intrude. I also recommend holding the lens with the rear facing downwards while you file it.

Now that I think about it, this outer ring is most likely to be where your mirror is catching. You may even be able to see faint rub marks where it hits.

Your goal should be to have nothing protruding beyond the level of the adapter, although you may be able to get away with .3 - .6mm depending on your specific 5DII

Hope that helps. Others on this forum will no doubt have advice to give you. Take it all on board and see what you think will work best.

Cheers

Biotars are cool. I have a 75/1.5 M42 that I should use (or sell!) more than I do. Very unique look.

I'd take of the M42 adapater, mask off the whole lens with masking tape, except for the rear rings, and then grind those down with an upside-down (bench-mounted) belt sander. It's a 10 minute job at most. I am sure you can get the mirror to clear no problem, tons of material to remove there.

-Ed

Thanks guys, i will try to file down the "excess metal" but i feel it would be better to dismantle the lens completely before i do this, but with earlier bad experience with dismantling some CZ Hasselblad lens i'm a bit afraid to do so...is there a good guide to repair old Biotar CZ lenses...?

atufte wrote:
Thanks guys, i will try to file down the "excess metal" but i feel it would be better to dismantle the lens completely before i do this, but with earlier bad experience with dismantling some CZ Hasselblad lens i'm a bit afraid to do so...is there a good guide to repair old Biotar CZ lenses...?

The risk of causing some issue with the lens by opening it up is far greater than the risk of a 5 minute filing job. I'm not trying to be offensive, but it is a no-brainer. If you are not confident with your filing skills, maybe you have a friend who is good with his hands?

If you were local to me, I'd do it for free, while you watched. It is really very simple.

It worked, and the lens is now a perfect match with my 5D MKII... thanks guys

Now all it needs is a good lube job, is there a good way to do this...? I can actually see the focus treads from the
back and can reach them with a syringe with either grease or oil...? (Grease it's probably the stuff to use?)

And again , i really love this lens with it's superb bokeh and unik way to draw the lines...

//Alex

First test shot with the "converted" lens... (my better half & my daughter Ella Zoe)

This lens renders so beautifully...

Good going!

Nice shots! Please show us more.

Yes more shots

I do love the Biotar look If I could afford it I would buy a 75/1.5, unfortunately I think the samyang 85/1.4 is a much more sound decision these days

Does your lens have something like 15 aperture blades?

Empire wrote:
Yes more shots

I do love the Biotar look If I could afford it I would buy a 75/1.5, unfortunately I think the samyang 85/1.4 is a much more sound decision these days

Does your lens have something like 15 aperture blades?

I actually think it's 12...

15, 12, its a lot either way!

More images from my new friend, the Biotar 58/2...

It would be nice to see these shots at a lower ISO. The noise really detracts from these pics.

pengland wrote:
It would be nice to see these shots at a lower ISO. The noise really detracts from these pics.



Haha, i like this noise and actually make my images grainy myself, this images were shot at ISO 400, but i won't show them to you, hahaha....

BTW! I just got these comments on the exact same pictures:
(So not everyone agree's with you, thankfully...)

______________________________________________

"Yeh you've managed to get a really film-like tonal range there atufte

I like the first. It has lovely grain too! "

_______________________________________________

"Heh, best digital B&W I've seen in ages, well done. Fantastic photos too"

Hahaha

This reminds me of the quote on the top of the apug group:

"That is called grain. It is supposed to be there."

What a name for a lens though... "Bio-tar!"

Sounds like a fertiliser or worm food
Glorious moments for the Zeiss marketing dept

Ahhhhh.... I see...I made this comment in the hopes that you would show us what you lens can really do. Now that I understand the effect you were trying to achieve I can certainly respect that. It's rare to see "artistic representation" when showcasing lenses on this particular forum. It is however difficult or impossible to judge the characteristics of a particular lens when pics are noticeably altered (ie. increasing grain) or high ISO settings are used.