Does Letus Extreme lose more light than Brevis

If you are someone who likes to shoot f/2.8 for that certain sharpness and depth of field, the Brevis is a LOT faster than the Letus, about two stops faster. That's because shooting with the Brevis at f/1.4 is equivalent to the depth of field on the Letus at f/2.8. The fact that the Brevis has more depth of field than the other adapters gives it this advantage because you don't need to stop down necessarily to make pulling focus easy.


Marco
 
Marco, the DOF physically does not change, as that's a function of the lens and circles of confusion etc. What is different is the bokeh rendering/light efficiency and this certainly creates the impression that the DOF of these screens are different.
 
Dennis, Thanks for the correction. I have been trying to use the expression "Apparent Depth of Field" for this. For all practical purposes though "ADOF " is all that matters here anyway.

I want to second Barry's explanation of how difficult and painstaking it is to do truly accurate fair tests. I have a lot I'd like to do but I just don't have the time. I never posted stills from the tests I did do because it would have doubled or tripled the amount of work involved. Just didn't have the time.

By the way Barry thanks for the apology. We're all in this together. I've certainly learned much from your painstaking skeptism even if i think you sometimes take it a bit too far.

Lenny
 
Pure, I am not asking Barry for anything that he wouldn't want to do and he had already expressed his intention of doing the shoot-out as opposed to just a Brevis test before I repeated myself saying that I would love it if it were in fact a shoot-out.. I have to admit that I do forget or to be more accurate :) don't even GET how hard the test and comparison that HE plans to do will be... hehehe... it is a common phenomena for me to read the title of the test and imagine what I'll find inside but get completely flabbergasted by what I actually find after clicking on it... as I said numerous times I know little about optics and it is hard for me to understand how much goes into it.

But Barry, it is a good point that Pure brings up as I know I wasn't taking "you" for granted but I have not a clue of how much time this would take... or actually I have an idea but I am certain it is nothing but my imagination :) so thanks a million for ANYTHING and thank you regardless, even if you don't , for all the other posts and countless replies to my posts... And again, thanks to ALL of you guys, you included Pure, that know a ton more than me and take the time to answer a little question here and there for me...
 
I am a bit lost on how the CF1Le will render the bokeh at 2.8f as opposed to faster lenses. Since my main concern with the HVX was speed I was focusing on image problems to find out if the added speed was in fact a attainable a a low "cost". But I forgot to look at the other factors that should be taken into account when deciding between the zooms and primes.

Being able to use 2.8f zooms with the same sensitivity as the faster primes might be a great thing but what will I give up besides the possible better feel to the focus wheel and possible longer draw on primes such as the all manual Nikons or maybe even Zeiss if I can find them...
 
USLatinContent said:
I am a bit lost on how the CF1Le will render the bokeh at 2.8f as opposed to faster lenses. Since my main concern with the HVX was speed I was focusing on image problems to find out if the added speed was in fact a attainable a a low "cost". But I forgot to look at the other factors that should be taken into account when deciding between the zooms and primes.

Being able to use 2.8f zooms with the same sensitivity as the faster primes might be a great thing but what will I give up besides the possible better feel to the focus wheel and possible longer draw on primes such as the all manual Nikons or maybe even Zeiss if I can find them...
Click to expand...


this is just my opinion.... but i think what the brevis "gives up" is the "film look"... yes it has a shallower depth of field and looks better than just the bear camera, but it just doesn't look anywhere near as good as the M2 or the SGpro.
the brevis has amazing technical specs but the footage just doesn't feel right to me. this is including CF3 footage

it's all personal preferences though....
 
But what about the possibility of a GG beyond the CF3... what then... cause why wouldn't it be possible for them to make one?

I guess the only fear is that the vibrating GG might not move fast enough for decent shutters with a 100% non translucent GG?
 
marco0782 said:
the Brevis is a LOT faster than the Letus, about two stops faster.

Marco
Click to expand...
Marco your statement is totally baseless. Dennis already answer the DOF statement, so I am only going to answer the above statement.

If this was true the Brevis would be gaining over 1 stop over the camera without any adapter.

Like Barry previously said unless Dennis came up with an innovating new system that actually produces gain rather than light loss, that would be an impossibility.
 
Its very hard to put these differences into words and it really does come down to taste and preference. I wouldn' say the CF1L has less "film look" but it is definitely less diffused. That can be good or bad depending on your preference or the nature of the job. You could also describe it as "clean".

I'm using a Pro35mm with an HDCam next week. For my taste the Pro35 is far too diffuse and flares highlights too much. For this job I'd rather have a Brevis CF1L, but it won't work with an HDCam. I prefer the SG for interviews cause I like the soft feeling and lower DOF. For drama I don't know which I prefer - might depend on the shoot. I don't like the CF3L because I can't seem to use my zooms with it and I like the Nikon zoom.

There is a post somewhere of stuff shot for a feature with a Brevis that looks great. I thought the Redrock was too soft and diffuse but I've seen great stuff with that too. The Letus is kind of in between the SG and the Brevis CF1L but there is some highlight handling that's not to my taste - I've been using it though to happy clients.

No simple answer, you can be very happy with any of them.

Lenny Levy
 
US, you're an astute fellow. The imaging element R&D program is by no means finished. We're very, very excited about what's to come :-)
 
Lenilenapi said:
There is a post somewhere of stuff shot for a feature with a Brevis that looks great. I thought the Redrock was too soft and diffuse but I've seen great stuff with that too. The Letus is kind of in between the SG and the Brevis CF1L but there is some highlight handling that's not to my taste - I've been using it though to happy clients.

No simple answer, you can be very happy with any of them.

Lenny Levy
Click to expand...

The feature stuff from the Brevis DID look REALLY nice. I remember that guys post and I did ask him for more footage. Classic case of knowing how to use your equipment and not getting hung up on it (guilty as charged).

To be dead honest, if I had the money I would have an SGpro and LetusEX (speaking at this moment, who knows what'll come out here soon). SGpro for high shutter, high iris scenarios and Letus for everything else.

Or I could just anti up and get a mattebox and some great filters to chop light. =P
 
Can someone link me to that footage?

Kholi, out of those options get yourself a matte nice box and filters for sure. Right? I am getting the RedRrock as soon as it it out. (hehehe... if all goes well with the financing, can't forget that)
 
USLatinContent said:
Can someone link me to that footage?

Kholi, out of those options get yourself a matte nice box and filters for sure. Right? I am getting the RedRrock as soon as it it out. (hehehe... if all goes well with the financing, can't forget that)
Click to expand...

It's always renting, my way. I can see the advantage of purchasing and owning, though, because the gear is universal: it sticks with your camera upgrade regardless. Another good feature of the newer 35mm adapters in that you can strap em on to other cams as well.

I want to wait for the Redrock, I'm sure it'll drop sometime soon.
 
Yea, I figured that's why you didn't have it allready.
From what I gathered by e-mailing directly was that they have not had any setbacks (YET) for their Feb release but it is not a hard date by any means.

While we are off-topic... do you have their FF? And does anyone know if it will be the only unit that will work with their remote FF?


About the GG development program Dennis, this is why I asked you about the GG details... really what I was trying to get out of you was more info about the new one you guys are going to release soon. And more spesifically, what I want to know is if this will be a 100% non-translucent? And if it won't be is it because you guys are getting SGpro-like footage with it already? I don't know if that will be possible at all with the Brevis, but you know what I am saying here... talk about it! please :)
 
What do you mean by 100% non-translucent?

Someone threw out that word as an explanation of why the exposure issue happens and now it seems its being used to describe the look of an adapter screen. I don't know if this a good choice of words as it implies that there is some light coming right through the screen and screwing with the image. I 've never seen that.

lenny
 
That's exactly what it means and what I am saying. This is being extensively discussed on this thread as posibbly the main reason why the Brevis' light loss curve is not linear and as the likely reason for hot-spotting at smaller apertures on the taking lens.
 
I'm not going to continue to belabor this any longer , but I have never heard of hot spotting at small apertures being an issue. Somebody here mentioned that , but its far from proven and I have never seen any examples. Maybe I missed them. Nevertheless you can't even use a Brevis at small apertures anyway because you will see static grain. It's a f4 or 5.6 tops unit because its a vibrator.

Did someone post example of Brevis hot spotting? Maybe I'm out to lunch and missing something that's obvious to many of you and if so i'll be glad to eat my words.

In general I find myself defending the Brevis on these pages alot - which is weird because I don't have any special attachment to it. I don't even use it as my primary adapter most of the time.

But it seems to get knocked a lot here and claims are made for other adapters vs. the Brevis that I often find highly questionable. =

Lenny Levy
 
John, our 2/3" relay project is going quite well. In fact, the HPX500 should be here this week for testing. This is by far the most I've ever even remotely considered spending on a camera, so anyone in Thunder Bay looking to rent one take note :-)

US, our CINEFUSE R&D program is something we keep a very tight lid on. All I can tell you is that CF1 and CF1Le will continue to be the offerings for maximum light efficiency, and that the next offering is something quite special.

Btw, check this clip done with CF2Le :-) Ironic, given that the outside temperature is dropping to -32 C here tonight...
 
Last edited:
Dennis, can i suggest an acrylic GG with a grain-less structure. about the same diffusion as CF2 maybe slightly more. it'll be usable at all apertures and can be used static if you're careful to avoid dust.

ay? what do you think? is that what you're working on? :D
 
You must log in or register to reply here.
Back
Top