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A superfast normal on the G1

phobus

Member
Pointed at the computer screen - not sure if this is the right way to do it. I can't tell the aperture exactly because I mounted the aperture ring upside down to get the lens to mount closer to the sensor for infinity focus.

f1.4



f-almost closed

 

m3photo

New member
Re: Carl Zeiss Jena Tevidon 25mm 1.4 etc.

Speaking of cheap experiments, I got a C mount adapter from Taiwan, and the Carl Zeiss Jena Tevidon 25mm 1.4 from eBay and its working out quite well for about $100 total for both.
Thanks for the tip off phobus. I think I got there just in time this morning, as soon afterwards they re-placed the advert and now they're selling them off in lots of 5. The thing is, logically, there are plenty of mounts for attaching other lenses to cine cameras but not the other way round (who'da thunk it?), so can you tell us all where you got your Taiwanese C-mount adapter?
Thanks in advance.

m.
 

phobus

Member
Re: Carl Zeiss Jena Tevidon 25mm 1.4 etc.

Thanks for the tip off phobus. I think I got there just in time this morning, as soon afterwards they re-placed the advert and now they're selling them off in lots of 5. The thing is, logically, there are plenty of mounts for attaching other lenses to cine cameras but not the other way round (who'da thunk it?), so can you tell us all where you got your Taiwanese C-mount adapter?
Thanks in advance.

m.
Hi, I got it from this thread - http://74.125.93.104/translate_c?hl...ge%3D1&usg=ALkJrhi_hQOZPEpXAhTI1xf6MbfYon4iEA
 

m3photo

New member
Re: Carl Zeiss Jena Tevidon 25mm 1.4 etc.

Cheers. Waded through the whole lot and got the gist of it (I think). Anyway I sent HawkPeng an email and we'll go on from there. From what I gathered, he's thinking about doing an FD to m4/3 variation too and somone's asked him to look into an Arriflex adaptor. If he keeps his prices down he'll be a welcome alternative to some of the others ...
 
V

Vivek

Guest
I can't tell the aperture exactly because I mounted the aperture ring upside down to get the lens to mount closer to the sensor for infinity focus.

Make a mark in the lens mount where the aperture should show when the lens is mounted on the adapter (and the camera), then dismount the lens.

Unscrew the 3 screws on the lens mount, rotate and position the mount close to the marked position and screw the screws back on. You will now have the lens that would focus to infinity while you can also see the focus/aperture scales on the lens.
 

phobus

Member
Make a mark in the lens mount where the aperture should show when the lens is mounted on the adapter (and the camera), then dismount the lens.

Unscrew the 3 screws on the lens mount, rotate and position the mount close to the marked position and screw the screws back on. You will now have the lens that would focus to infinity while you can also see the focus/aperture scales on the lens.
Great tip! I'll try that tonight!
 
This one doesn't have that limitation either.



About ¥10.000, coming soon.
Rabe says some Chinese adapters he has seen will for instance not allow the Kern Macro Switars to be mounted which have a back diameter of approx. 38mm. The recessed C screw mount on the picture seems surrounded by a ring that might do just that. I can tell more once I receive the adapter
 

phobus

Member
The one I have is limited in that way.. I unscrewed the back of the tevidon lens and shaved off a bit of the edges to make it fit (with a dremel, it was easy because everything is made of brass). If I had an expensive lens, I'd wait for the adapter monza posted, but for $25 its pretty much a no lose situation.

Rabe says some Chinese adapters he has seen will for instance not allow the Kern Macro Switars to be mounted which have a back diameter of approx. 38mm. The recessed C screw mount on the picture seems surrounded by a ring that might do just that. I can tell more once I receive the adapter
 
V

Vivek

Guest
What Peter said is true. The Som-Berthiot 25/0.95, for example, needs to be machined, even to be mounted on the proper adapters (Rabe or MS Opticals).

This is not a trivial adapter to fabricate, BTW.
 

GDI

Member
Any idea if a Canon 0.95 c-mount will fit in the cheap adapter? If so - how would I go about ordering one?

Thanks!
 

m3photo

New member
Re: C-Mount Adapter

Any idea if a Canon 0.95 c-mount will fit in the cheap adapter? If so - how would I go about ordering one?

Thanks!
OK, don't know if it will fit what you want to put on it but for $25 I went ahead and ordered one (Postage to Europe is $6 on top, plus 4% Paypal = total of $32.24). Send an email to the guy who makes them. He's just improved the original design and I think from the photos at least, that it's easier to work with.
E-mail: [email protected]
 

GDI

Member
Re: C-Mount Adapter

OK, don't know if it will fit what you want to put on it but for $25 I went ahead and ordered one (Postage to Europe is $6 on top, plus 4% Paypal = total of $32.24). Send an email to the guy who makes them. He's just improved the original design and I think from the photos at least, that it's easier to work with.
E-mail: [email protected]
Thanks. I did email him - he says:
The largest diameter is 36.5 mm that is best for infinity location.
If the diameter is over 36.5 mm , less than 47mm.
It can fit the adapter,but can not to infinity.
So it will not reach infinity with my Canon. Maybe the next version released will...
 
P

psurfer

Guest
We need to clarify some things:

1) The photo in post #53 above, appears to be a C-ltm adptr -- m3photo, is that what you ordered for $25 +s/h? Or a direct C-to-G1 adptr?

2) GDI, re post #54, I assume the specs hawkpeng emailed you were for his C-m4/3 adptr, right?

A needed spec is the depth is that 36.5mm opening?
 

m3photo

New member
Re: Adapter Photo

1) The photo in post #53 above, appears to be a C-ltm adptr -- m3photo, is that what you ordered for $25 +s/h? Or a direct C-to-G1 adptr?
QUOTE]
I hope it's the newer model the seller is offering, although you're right in suspecting it's an LTM type as there don't seem to be any lugs visible on the rear face, maybe my mistake in copying and pasting the shot, sorry.
This one is the older model:
http://jorson.dyndns.org/ognn/attachments/forumid_13/20081219_78b23171b8fbf9b59251lonLws6FJN5u.jpg
By the way, Hawk Peng says that the price for the newer model is $35 - Add postage and 4% PayPal.
 

m3photo

New member
Re: Adapter Photo - More

This is the page I obtained the original image from:
http://jorson.dyndns.org/ognn/viewthread.php?tid=592&extra=&page=7
Scroll down to the 3rd and 4th shots to see the C-Mount to M4/3 adapter fitted on a Fuji TV lens.
The first photo I posted seems to be of the front of two styles of the same adapter, hence there being no lugs apparent.
Please excuse any confusion I may have caused. I'll report back once I have mine with some C-Mount lenses to try out.
 

GDI

Member
We need to clarify some things:

1) The photo in post #53 above, appears to be a C-ltm adptr -- m3photo, is that what you ordered for $25 +s/h? Or a direct C-to-G1 adptr?

2) GDI, re post #54, I assume the specs hawkpeng emailed you were for his C-m4/3 adptr, right?

A needed spec is the depth is that 36.5mm opening?

Yes, that is for the C-mount Micro 4/3. The specs he gave were for the diameter- the fact that larger lenses will fit but not reach infinity must be due to the stepped opening?
 

m3photo

New member
Re: Carl Zeiss Jena Tevidon 25mm 1.4

Speaking of cheap experiments, I got a C mount adapter from Taiwan, and the Carl Zeiss Jena Tevidon 25mm 1.4

all at f1.4
How did you get such good focus from this lens? Mine's either a dog or it needs a lot of machining ...

Also at f/1.4:
 
R

Ranger 9

Guest
A rough indication could be given by the film/sensor size in mm (data from Wikipedia):

4/3 : 13x17.3
M8 : 18x27
16 : 7.49x10.26
Super 16 : 7.41x12.52
35 : 18x24

The only lenses covering the whole μFT sensor according to these values would be cine lenses intended for 35mm. Other lenses, such as some Super 16, may have a larger coverage than theoretically needed.
Here is a diagram I found on the dvxuser.com website (in the section devoted to the RED camera) that may help visually explain the different coverage areas of various kinds of cine and CCTV lenses. From Peter M's data above, it appears that cine lenses covering the "RED S35" frame will have some safety margin on Micro 4/3, and lenses for "RED 35" will be close:

 
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