Full Frame Relay for 2/3' cameras and Letus

eddavid

eddavid

Carbonite Member
Is anyone still interested in making a full frame relay for cameras like the Sony PMW-350? I'd love to get one to use my Nikon glass on it. Also what is going on with Letus these days? Rooting for these guys. I still think a great video camera with a nice DOF adapter is still worth it. Am I alone? Hello?
 
In few days I will deliver to the first clients and Wayne my modular relay system...

Wayne will have on hands the S35 version as well as the conversion kit for Full Frame 35mm, he will be able to demonstrate the SGblade with 2/3 cameras.

The GG.relay is able to accommodate a connection kit for Letus adapters also, if I have enough demand. A 1/2 - 1/3 conversion kit is possible also for small cameras.
 
Great - Wayne please let me know how it goes. I would be interested in the Full Frame 35mm kit
 
Our B4 zooming relay should work just fine with the Letus too. I'll be posting some footage likely this week from our relay on the Si-2k rig that we have here. Our relay is capable of zooming anywhere between academy and full SLR frame widths, and works as a direct connect to the SI-2K.

Cheers,
Dennis.
 
Great news Evangelos! I saw the Letus FF35 1/3" relay and it had a lot of vignetting. Optics are a tricky business indeed! Look forward to reading more about your relays.
 
Thanks Jeff, SGblade is handling better the vignette issue of FF35 because you can change GG's and use the RR2 which doesn't vignette at all... you lose light to get the best performance on vignette but that's life...

Tomas all I can say is that Wayne is really on it and it will have his tests done in the next weeks...

On the other hand I have deliver also one to Chris Albert in Israel a CBS 60 minutes cameraman that he will do some tests also...

There is a relay in stock for anyone interested... the web site will be up in a couple of weeks also...

more info in this thread:

http://waynekinney.iforumer.com/viewtopic.php?p=6962&mforum=waynekinney#6962

at the bottom, post 6.
 
Dino said:
Great news Evangelos! I saw the Letus FF35 1/3" relay and it had a lot of vignetting. Optics are a tricky business indeed! Look forward to reading more about your relays.
Click to expand...

Hi Jeff,

Was this with the Ultimate? I really have on target this sept-up for the HPX300....

Can you elaborate on that matter? What lenses were you using?

Thank you so much in advance... Your comments will be truly invaluable before I plunge the money!

My best.

Henry Epstein
 
Henry,

Two Ultimates, Zeiss ZF 85mm and a wider Zeiss. Given that P+S had to crop Academy frame 18% to avoid vignetting, I"m dubious about any relay not vignetting with FF35.
 
Since I have done a lot of research on ground glasses, all I can say is that the vignetting issue is totally related with the ground glass used.

Vignetting is related to the angle of light rays that come out of the back of the 35mm lens. If the lens is fast 1.4 i.e. then the exit pupil is large that results to more telecentric behavior, if its 2.8 then it has small exit pupil and is much less telecentric. A telecentric lens has the exit light rays to hit the film plane or sensor or GG vertically (90 degrees) the less telecentric is having exit angles that can be up to 60 degrees... the center of a lens exit is always 90 degreees as you go to the edge it gets more and more less telecentric so the result is vignette on GG's.

To build a ground glass that has less vignette you have to be made it in a way that will capture the non telecentric rays. To do that you need diffuse...

But diffuse results to softer image and less light efficiency...

So adapters that can't change GG's can't perform the best with an average diffuse GG... Its needed by the user to be able to change GG's according to the needs of the project.

So for FF35 applications an SGblade is much better since it has three options on diffuse, RR3 is very sharp and less diffused thus more vignette, the RR1 is the all around its average in all aspects and RR2 with slightly heavier diffuse better bokeh NO vignette in FF35 but a lot of light loss...

I prefer the RR3, I accept the slight vignette in FF35 and to avoid it I use fast lenses...

But in general is a matter of taste and is depending on the application.

The lack of exchangeable GG's is very big problem with FF35 applications...
 
Evangelos, if I understand your explanation then stopping down a lens will increase vignetting? I've always thought that it was the other way around?
 
Huy Vu said:
then stopping down a lens will increase vignetting?
Click to expand...

Yes exactly... if you test it with an adapter that can change GG's this is the result... only by comparing different GG's is visible.

With RR2 in SGblade there is absolutely NO vignette in FF35... even with an F3.5 Leica lens...
 
Evangelos,

Thank you for your explanation. My experience with the Letus B4 Compact, Pro and 1/3" relays is that stopping down definitely makes vignetting more prominent.

It was more obvious with the 1/3" relay and as it turns out, the lenses being tested were mostly f1.4 and often wide open. I attributed the increased vignetting over what I am used to with my B4 Pro to be due to the FF35 of the 1/3" relay. With my Ultimates, I am unable to change the GG, as you know.
 
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