Does Letus Extreme lose more light than Brevis

Jason is I think on the right path here ( as is Dennis who has been talking about this issue for years BTW) . I've tested all 4 of the above adapters as well as the CF1 & CF3 and stated many times on this forum that a good general rule of thumb is that the more efficient a screen is with light the less linear it is at open apertures especially between 1.4 and 2.8. The Brevis in my exoerience doesn't even see light from the wider apertures so its response at f2.8 and f1.4 is the same. A Letus as I recall lost aprox 1 stop between 1.4 and 2.8 and a Redrock almost the full 2 stops. This is in the nature of adapter optics.

There are numerous pros and cons to either style of screen.

I think Davide is correct about where Barry left the issue but I disagreed with Barry and others about whether you can say which is closer to true 35mm DOF. That's not at all established in my view, and to me that expression gets thrown around way too freely.

I think many people find say an SGPro, a Brevis CF3 or even a Redrock prettier and say it feels more filmic. But "Film Feel "or "Film Look" and even Bokeh are not neccessarily the same as DOF. It may actually be the softness that people are responding to.

Does a Redrock or an SGPro have the same DOF as film? Who knows? Nobody on these pages has ever compared them. To do so you would have to compare either video blown to film and projected, or film transferred to video. Either way a pretty expensive test. Perhaps a careful test comparing a depth of field chart to a 35mm adapter would help. In any case whether you use Academy or full 35mm still frame size would also have a huge affect on DOF. And then there is Academy, Super 35, vistavision, panavision 70, anamorphic, cinemascope, 16:9, 2.35: 1, etc, etc, etc and all affect DOF.

My own guess is the contrary of most thinking. I think that probably the Brevis CF-1 screen scatters light the least and thus might be more similar to film in being closer to the strictly optical circles of confusion (the out of focus parts of the image). The denser screens probably diffuse those circles of confusion more through scattering and thus might have less DOF than film. Its just a wild guess though.

Film has both the softness we like in a dense screen and more resolution than any video camera even without an adapter, so you're just not going to get a perfect emulation. Not possible. Many people find an HDCAM with Zeiss digi primes more filmic because of its sharpness and clarity but the DOF is much higher than a Pro35.

In any case I think trying to determine which adapter is closer to true "35mm film" is a bit of a waste of time. They are all alot closer than an untreated 1/3" or 1/2" chip- cameras.

Pick the tool that you like best for whatever you want to achieve, not for its similarity to something it really can't match.

- Lenny Levy
 
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IF I felt like wading back into these waters (and I really don't, seeing as every time I do it seems like a pack of sharks start attacking from whichever adapter happens to be being called into question) but if I was going to do it, I'd use my 35mm movie camera and my M42 lenses, which happen to work on the film camera and on all the adapters, so it'd be the same lenses across the board. I'd test for light efficiency, DOF, bokeh and FOV across the board. And I'd say what the results are. I'd use the same video camera for every test, with the same lens, so the only difference is the adapter. And I wouldn't give a flying fig who disagrees or who gets different results, because the results would be the results. No spin, no bias, just charts and photos of exactly what each unit produces.

That said, that's probably the better part of a week's worth of work to do it right. This is no small task. And my reward would be to be eviscerated by fanboys of some or other adapter, whoever's sacred cow gets gored. And it'd be expensive (film stock and time). And, I don't have all the adapters, I'd have to either buy them or depend on the kindness of DVXUsers to loan 'em.

And even then, the results would stay relevant and accurate only until the next revision by the adapter makers, which (at least in the case of Letus and CineVate) seems to happen monthly!

So, with that said, if you guys want me to do the Adapter Test From Hell, I could maybe get to it in June, but you'd have to get all the adapter makers to agree to send their latest versions 'cause I'm not gonna spend $5,000 to buy 'em all...
 
That is very generous of you Barry. I know that if it was me doing what you are offering to do, it would cost me out of pocket a few thousands of dollars. Even if I didn't have to buy the adapters just in time not producing money.

I don't think you are commended publicly enough for your researches. I want you to know that we really depend on you and few other that do leg work sore of speak, so we know what to expect before buying new technology.

By the way good report on the HVX200a and the upcoming 170.

Thanks
 
That said, that's probably the better part of a week's worth of work to do it right. This is no small task.


Yup probably about a week's work. I'm amazed that you are actually offering to do it Barry. I hope no one really expects you to bother.

It would be interesting, but in the end the adapters would be different in weeks and it wouldn't make all that much difference to anyone. These are great tools - there is plenty of information out there already. Use them and make pictures.

Lenny Levy
 
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Barry if you did it you'd go from celebrity to becoming the Greek God
of film making on a budget... add that to your oder medals... but not expecting to have you do it...
 
He's right... there's really no reward in doing that sort of test. Someone's gonna cry, someone's gonna sigh. Might as well just realize what works better for you and figure out how you want an adapter to perform then stick with that.
 
Thanks for the offer Barry. If you ever do that test maybe you could place it in an issue of DVXUser Monthly. It'd be sure to attract a huge amount of readers and because of that maybe you guys could negotiate to get more advertising in that issue to make up for the cost of film stock and time.

At the end of the day I don't think people should be choosing adapters based on how 'filmic' they look but based on whether the look they give suits the projects they want to do.
 
Actually Hubert's Arri 2C 35mm camera showed up today in fine shape from Holland. So hang on :-) Btw, Barry the overview as you have described has pretty much been done already in what sounds like the most thorough review (free I might add of any outside bias) ever done on 35mm adapters. Doing a thorough review before that "super-review" comes out would be a waste of time.
 
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Barry the overview as you have described has pretty much been done already in what sounds like the most thorough review

You care to tell us were it is or when it is coming out.

(free I might add of any outside bias)

All reviews are bias. It is just human nature

ever done on 35mm adapters. Doing a thorough review before that "super-review" comes out would be a waste of time.
 
I had nothing to do with the review, and only became aware of it's existence long after it was done. It would be completely out of line to say anything else about it at this point, other thain I'd expect it in a matter of weeks...and I have very little idea of what the conclusions were. Knowing who did it, I'd expect it be very clinical, and free of any bias.

I'm pretty much done with this thread otherwise as we've done our own clinical analysis of light loss, presented it a very open manner for the world to see, and we have no interest in anything less than the truth when it comes to our products. Cheers and happy debating :-)

That Arri 2C 35mm film camera kit (all 200lbs of it) showed up today. Our front end guy Hubert had it stashed in Holland from his film and animation studio days. Big smile as they were reunited. We should have it purring with some film in the can within weeks.



arri.jpg




http://www.cinevate.com/
 
wow, more time spent on these boards comparing and complaining about adapters than making films....shame.
just make your own and you can have all the specs you want.
 
Lenny, we're going to have it overhauled and shoot with it! Its first job will be in a 35mm cine film vs CF1Le, 2Le, and 3Le comparison (at cine and SLR frame sizes). Hubert has 3 motors in the kit allowing variable frame rates so we're looking forward to playing a bit down the line with the rig. Although the primes are gone, we've got two monstrous Angeniex zooms, one of which is a T2.2
 
Wow I guess that's our test!
That should be very interesting.
You guys are wild. I wish I lived near you to take part.
I guess it won't be the "unbiased" comparison that many here seek, but it should be fascinating.

Kind of pricey isn't it though.

Lenny
 
Actually not so bad...the camera itself has been adopted for the cost of shipping, and we won't be shooting too many frames. Either way, it seems appropriate for a company trying to emulate 35mm film to actually shoot with it. Something we don't discuss online too much is the desire to serve as a resource for local film-makers in our area where the closest rental shop is 700km away. So when we're not using the equipment, it's available for rental at reduced rates. Our facility has turned into a pretty relaxed "hang out" for local film makers which not only keeps us involved and supporting local projects, but we get immediate feedback on prototype stuff used in the field. Warm fuzzies all around :-)
 
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