Cinevate achro on M2?
 

Has anyone actually used a Cinevate achromat on an M2?

I know in theory it'll work just fine, but I'd like to know for sure. I don't want to lose $250 trying to save $150.

Thanks

Sam:

I have used the Cinvate achromat on the Redrock DIY spinner I built. I haven't actually seen an M2 yet, so I don't know if they also have a consener inside the unit, like the Letus 35a has. With the spinner, and the Cinevate achromat, and shooting with my FX1 or my HV20, I have to add about a 4.5 to 5 inch spacer between achromat and spinning ground glass, in order to zoom to avoid vignetting. At that spacing, I get a lot of play room. I know other camera are able to focus and zoom at closer ranges, but just know it depends on your camera.

I would be inclined to agree with Chris's post. As long as you can live with the setback of 4.5 to 5.0 inches it should be okay. Longer setbacks also trend towards less edge softness or distortion.

If in doubt, email Brian Valente at Redrock directly or through dvinfo mail. He cruises here from time-to-time and should still have a touch of the experimental enthusiast in his essential psyche.

As an experiment, I made up a bayonet style relay mount to go between a Sony Z1 and a Mini35 for JVC GY-HD100. I used the Century Optics 4+ achromatic dioptre from my home-build AGUS35 and arranged the adaptor to screw straight in the front of it.

This concoction replaced the JVC GY-HD100 special optical relay module. It worked just fine, better resolution than my own device which one would expect from the work of the ex-ARRI engineers at P+S Technik.

Now if only I could afford the JVC or Sony's EX1.

Thanks Chris,

I don't want to play around to much, so I'm probably gonna buy the one from red rock just to be safe. I know even if I buy red rocks achro, I might still be spacing the lens and gg, but at least I know without trying that it will work.

I'd still be interested in hearing from anyone else who has direct experience with this set up.

im using the Cinevate Achro with the M2 and its working fine for me... basically the same magnification as with the redrock.... just the redrock is more expensive....

Actually, our non-flip achromat (the one you're looking for) is a bit more powerful than the M2 version. It will work perfectly.

Dennis Wood.


What is the power of your 72mm diam flip achromatic dioptre?

I am doing a bit of a fiddle with a Mini35 onto an EX1 tomorrow using my AGUS35 optics and a bridgepiece I made to mount a JVC HD100 version less the relay up to a Z1.

The 58mm dioptre is okay for the Z1, obviously 72mm would be better as the corner falloff from the smaller exit pupil of the 58mm and the inherent edge falloff at full zoom of the camera itself are cumulative. The 58mm is a Century 4+.

I think the Mini35 GG diameter, less its excursion may be a bit tight for the 1/2" EX1 at full zoom but there might just be enough to cheat a 2:35 pretend cinemascope frame. However one cannot know until one tries. If it vignettes on the 58mm, then I may be looking for a 72mm 4+.


Phil Bloom.

If you have a peaceful and serene moment on your US assignment and have good recollection and time to post, can you remember what power achromat and what setback distance you used to make the EX1 satisfied with the Letus Extreme?

Thanks Dennis

Bob, right around +8. It compares in actual use to the Asian +10 which appears to be incorrectly rated.

Dennis.


8+ for the flip adaptor?

Your adapter must be in a similar league compact size-wise as the PRO35.

I've been out of touch with your developments of late, but it seems on the surface of things to me, that your existing layout with little modification might be in with a real chance with 2/3" cameras and of course 1/2" if direct relay comes along.

Bob, we are in fact working very hard on a multi-format relay for the Brevis system right now. The achromat of course won't be used.

That spec of +8 is with regard to the non-flip achromat...not the flip one.