Does Letus Extreme lose more light than Brevis
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Dennis Wood
DVXuser Sponsor
No offense here. When you stop laughing at yourself, others tend to do it for you 
Douglas Villalba
Well-known member
As far as I know no one without a vested interest has test it side by side.
Even if someone had done with 100% certainty both sides will still claim different results.
I offered a simple two identical cameras one with my LEX and Nikon 1.4 and the other with Brevis also with Nikon 1.4. Run them both through my switcher split the image and set the aperture at 1.4
My guess is that the LEX is 2 stops brighter at 1.4 and it will even out at 2.8 or 4.
That seams to me like a simple test.
No one I know owns the Brevis in South Florida so I can't do it on my own.
My offer still stands :happy:
Lenilenapi
Carbonite Member
Douglas,
At the risk of entering the fray here again, I have to say honestly after explaining my tests many times that I find the above comment personally unfair. Are you suggesting that I have a vested interest of some kind?
My partner and I compared 3 units (SG, Brevis, and Letus) as objectively and carefully as I could with absolutely no axe to grind as I owned all 3 and still do own all 3. I explained my results in detail.
I talk to all three manufacturers and respect all of them immensely. I'll be the first to admit that my results haven't always been the same as some other tests but it certainly wasn't because I had an axe to grind. Its hard to do perfect tests and the units themselves might even vary a bit. My Letus apparently had a prism problem, but i have no idea if that affected the results, I tend to doubt if it was extremely significant but it may have had some affect. All in all I think my tests were objective, careful and informative.
I did get into a quite lengthy and spirited defense of the Brevis because I thought it was being unfairly maligned and its optics and speed misunderstood. But if you asked me which was best I'd tell you the same thing I said 6 months ago - all three have their pros and cons. Even which one is fastest isn't a simple answer.
At this point though the advent of flips on all three plus their attempts to tackle the Ex-1 and the announcement of the new Letus just complicates trying to do objective tests more and more and i can't afford them all anymore.
By the way, I could be wrong, but I don't think Barry ever said he intended to do adapter comparisons, that was a fantasy that was started on this forum.
Incidently my guess is that you are way off. The Letus at f1.4 will be roughly similar to a Brevis at f1.4 or 2.8 ( no difference). At f2.8 the Brevis will be brighter by at least a stop.
Lenny Levy
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Douglas Villalba
Well-known member
I meant side like with a switcher split screen. Similar to what Dennis did with the Brevis but with both at the same time.
I am 100% sure of what I claim and you seam to be 100% sure of your test, but we still disagree.
I would love to do the test my self and if I do and come up with the results that I think I would, I don't think that you would agree with my results. That doesn't mean that you are calling me a lier.
I think it was already established that there's a trade-off for the Brevis' "light efficiency". At the end of the day, just use what you want to use. For those seeking information I'd suggest buying the adapter that behaves in a proper fashion that way you don't have to wonder what might be happening to the image under certain circumstances.
I'm more than happy with the Ultimate and it's linear light performance.
I'm more than happy with the Ultimate and it's linear light performance.
Tim Naylor
Veteran
Use one camera, a greycard and a wave form. One camera eliminates variables. I think Kwan and Beat did some tests with both. Not sure if they did light efficiency tests though.
I think testing wide open holds little value as most lenses suck wide open. I'd be most interested in 2.0-5.6. But primarily 2.8 since that's where a lenses performance really begins to shine. My guess based on my past Brevis and current LEX, is that the Brevis will have about 2/3 stop advantage.
JasonFox
Internet Sensation
Cripes, look what I've done! I just thought Barry was going to do a test to try and explain the Brevis's non-linearity. NOT compare adapters. I have a Brevis, I dig it. But I'm still curious as to the science behind this attribute. (I know Dennis has a video showing it, but I'm sure a non-Cinevate person doing such a study -- especially Barry -- would carry more water with certain individuals.)
Anyway, quit posting. Go shoot something.
Anyway, quit posting. Go shoot something.
Douglas Villalba
Well-known member
After I shoot I do some editing.
Have you render a 30 sec. commercial with Motion animations?
What do you want me to do while I render?:thumbsup:
Have you render a 30 sec. commercial with Motion animations?
What do you want me to do while I render?:thumbsup:
Arrik
Well-known member
JasonFox
Internet Sensation
Hmmm. Perhaps you should stick to in-camera effects.
Lenilenapi
Carbonite Member
Jason,
I'm curious too. I've posted some conjectures but they don't complete the picture. My guess is that Dennis has some proprietary things he does with the screens that change how they handle imaging. Without knowing that, speculation may not get you too far.
It doesn't worry me though as the important thing is how they behave.
Lenny
I'm curious too. I've posted some conjectures but they don't complete the picture. My guess is that Dennis has some proprietary things he does with the screens that change how they handle imaging. Without knowing that, speculation may not get you too far.
It doesn't worry me though as the important thing is how they behave.
Lenny
I believe Barry said after having Dennis explain to him the science behind the CF1 diffuser he accepted the fact that's it light response is non-linear, and decided not to do any tests. If I remember correctly Barry's conclusion was that the CF1 diffuser is able to react that way because it doesn't mimic 35mm motion picture depth of field the way the sgpro or letus does. It creates a shallower depth of field but not 35mm motion picture depth of field and bokeh.
Maybe Barry can chime in on this but I'm nearly certain that he went over to Dennis' side and agreed that the CF1 has a non-linear light response. The cost of that non-linearity, he said, is that you are losing the 35mm film-like shallow dof look that you get with the m2, sgpro or letus.
Jason Ramsey
Admin
Increased light efficiency typically means less "film like" depth of field, and more "film like" depth of field will typically mean less light efficiency. An adapter maker can either push towards one extreme or another, offer multiple options via interchangeable diffusers, or try to find the best balance between the two... But, (at least not yet) you cannot have "perfect filmic dof and bokeh" and only get .5 stops of light loss. The two don't go together.
So, a CF1 equipped Brevis would probably be the most light efficient of the crop of adapters, but at the expense of a less "filmic DOF".
Likewise, (I have never used this) a CF3 is much more dense and loses more light, but possibly with the gain of a more pleasing DOF and bokeh appearance. Or, a Redrock, which probably loses the most light, but generally people say once you get it setup properly produces a very nice bokeh and DOF. The SGPro being a great balance between them (with a leaning towards bokeh rendition), and many people that use it I have often seen refer to how pleasing they think the bokeh and DOF properties are... The Letus Extreme probably leaning slightly more towards the light efficient side of things, but not so much so as a CF1 equipped Brevis. I've never used a Letus extreme yet, but I would think that it might not have entirely, stop-for-stop linear light loss either... I could be wrong, just a guess. I'd also be curious to see if the Redrock has a similar thing going on as the Brevis with regards to non-linear light loss... except in the other direction, being that it's more light hungry. Does it possibly lose more than a stop of light as you stop the lens one stop at a time? And, does this margin increase the further you close the iris? Basically non-linear like the Brevis, but in the opposite way. The brevis loses little to none early on, and by the time you get to the last few stops on the 35mm lens, it's pretty much become stop for stop linear light loss at that point. I wonder how the other adapters all perform in regards to linearity of light loss? I would suspect that they may all exhibit this in some form or another, as it's becoming quite apparent that things that were always "rules" before, are not quite so with 35mm adapters as there are different forces at work.
Anyways... Them's my observations from my little experience with adapters and from general statements I have seen floating around from users of the various adapters.
The thing to keep in mind is what may be a fault to one may not be to another. And, a plus to one person, may be a deal breaker for another.
What you need/want for your uses. Go out and shoot with it
In capable hands, I've seen some absolutely stunning footage from any of these 4 adapters with the Letus, Brevis and SGPro producing consistently good results from a wide range of users.
I'm pretty sure I could have closed my eyes and picked any one of those and been pretty happy with it, as I am now with the one that I'm using for the time being... It's not the latest and greatest, but it gets the job done for me, it makes pretty pictures to me (and apparently to others as well) and it performs consistently with little intervention on my part.
Later,
Jason
So, a CF1 equipped Brevis would probably be the most light efficient of the crop of adapters, but at the expense of a less "filmic DOF".
Likewise, (I have never used this) a CF3 is much more dense and loses more light, but possibly with the gain of a more pleasing DOF and bokeh appearance. Or, a Redrock, which probably loses the most light, but generally people say once you get it setup properly produces a very nice bokeh and DOF. The SGPro being a great balance between them (with a leaning towards bokeh rendition), and many people that use it I have often seen refer to how pleasing they think the bokeh and DOF properties are... The Letus Extreme probably leaning slightly more towards the light efficient side of things, but not so much so as a CF1 equipped Brevis. I've never used a Letus extreme yet, but I would think that it might not have entirely, stop-for-stop linear light loss either... I could be wrong, just a guess. I'd also be curious to see if the Redrock has a similar thing going on as the Brevis with regards to non-linear light loss... except in the other direction, being that it's more light hungry. Does it possibly lose more than a stop of light as you stop the lens one stop at a time? And, does this margin increase the further you close the iris? Basically non-linear like the Brevis, but in the opposite way. The brevis loses little to none early on, and by the time you get to the last few stops on the 35mm lens, it's pretty much become stop for stop linear light loss at that point. I wonder how the other adapters all perform in regards to linearity of light loss? I would suspect that they may all exhibit this in some form or another, as it's becoming quite apparent that things that were always "rules" before, are not quite so with 35mm adapters as there are different forces at work.
Anyways... Them's my observations from my little experience with adapters and from general statements I have seen floating around from users of the various adapters.
The thing to keep in mind is what may be a fault to one may not be to another. And, a plus to one person, may be a deal breaker for another.
What you need/want for your uses. Go out and shoot with it
In capable hands, I've seen some absolutely stunning footage from any of these 4 adapters with the Letus, Brevis and SGPro producing consistently good results from a wide range of users.
I'm pretty sure I could have closed my eyes and picked any one of those and been pretty happy with it, as I am now with the one that I'm using for the time being... It's not the latest and greatest, but it gets the job done for me, it makes pretty pictures to me (and apparently to others as well) and it performs consistently with little intervention on my part.
Later,
Jason
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Douglas Villalba
Well-known member
Yeah, that would be nice. Chroma Keying and titles in camera. Maybe I should ask Panasonic for their next update to include it.:undecided
Adam J McKay
Veteran
correct me if im wrong, wouldn't not losing any light when stopping down the lens be a bad thing? I use aperture to control exposure all the time and going from f1.4 to 4 without light loss would do me no good whatsoever other then increasing my depth of field slightly. And as many have mentioned before, there is a level of light loss that would be a good thing, example being if you are shooting 1.4 or even 1.2, that is going to let in alot of light, so an adapter that loses a stop and half of light is almost going to act like suedo nd filter will it not? Allowing you to shoot with a fast aperture and not have to fiddle with on camera f stop and shutter speed nearly as much. I think this is why I am personally drawn to the SGPRO. And for me, this lack of light loss would be a detturent to buying the brevis.
my 2 cents
my 2 cents
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Dennis Wood
DVXuser Sponsor
This is precisely why you have a choice, and why we're the only company promoting interchangeable imaging elements (six in total). You can easily swap in and out the formula of bokeh and light loss that suits you. In our very first beta testing process it was quickly apparent that there were two camps in the adapter world. One wants light efficiency, and the other wants very shallow DOF. With the Brevis, you've got these covered in one unit, and now with the MP.1's external oscillation adjustment and microprocessor control, we've made it even easier to tune your image.
Don't forget that our imaging element R&D program is in constant forward motion...and the latest drop-in addition will knock your collective socks off...I promise. It won't require you to buy a new adapter either
Btw, the most comprehensive technical review of 35mm adapters ever performed (7 units covered) has been done already by folks who are very good at this type of thing. All I know for sure is that the review is finished, and should be made public very soon. I also know that our light loss observations have been corroborated 100%.
Don't forget that our imaging element R&D program is in constant forward motion...and the latest drop-in addition will knock your collective socks off...I promise. It won't require you to buy a new adapter either
Btw, the most comprehensive technical review of 35mm adapters ever performed (7 units covered) has been done already by folks who are very good at this type of thing. All I know for sure is that the review is finished, and should be made public very soon. I also know that our light loss observations have been corroborated 100%.