Letus Extreme- Footage & Testing - Shutter / Slow Motion

Ryan E. Walters

Ryan E. Walters

Well-known member
Alright, for those of you who missed it, here is my review of the Letus Extreme in PDF form. Last night & this morning I did some further testing, with the shutter speeds and with over cranking for slowmo effects. You can download the full resolution stills as well as the sample videos in the zip file below. Otherwise, the enjoy the sample videos. :)

It looks like you can do over cranking, as that is not an issue as long as you have enough light. The ground glass was visible in the first test image, but in the out doors test it is not visible. It is almost the same for the shutter speeds- if you get enough light in then the ground glass almost dissapears. The major problem comes in when you have a really underexposed image- this is where things fall apart.

Over all I continue to be very happy with the adapter, and I'm looking forward to using it in my work.

Sample Video- Interior- Letus Extreme & HVX- (7MB)
http://www.235studios.com/REW-LEFootage-Glass-Chess.mov

Sample Test Video (Shutter speeds & over cranking)- Exterior- Letus Extreme & HVX- (7MB)
http://www.235studios.com/REW-LETest-ShutterSlowMo.mov

The Latest Full res Test stills: (43MB)
http://www.235studios.com/Test02.zip

The original review I wrote up in PDF

The original full res test stills: (31MB)
http://www.235studios.com/REW-Logo-LETest.zip

Enjoy!

(Sorry but there will not be any full resolution video, as I have uploaded those clips to sell on iStock. so if you want them you can see them and get them there sometime soon.)
 
Ryan, for the interior chess piece shots, what was your lighting setup. It's hard to know if you are showing the advantages of low light if you are, for instance, using a couple of 250w spots....If this is typical practical lighting, then that's a different story.

Do you know what I mean?

Thanks,

D/
 
sold for me also.will purchase friday.finaly an adapter with low light capability,very sharp,good bokeh,and best of all it flips without the mini35 price tag.also these guys took alot of heat over the older adapters but no one but them has answered the call for a flip at this price range up till now.quyen,im not a fair weather fan, i've been a supporter from long ago.i hope you put the mini35 out of buisness for trying to rob us poor indi filmakers.
 
The corners are soft!? Ryan try the rez charts again with a different lens. make sure its not the lens itself causing the corners to go soft.

Also, the shutter speed test looked good. looks like youre safe till 1/250th.
 
disjecta said:
Ryan, for the interior chess piece shots, what was your lighting setup. It's hard to know if you are showing the advantages of low light if you are, for instance, using a couple of 250w spots....If this is typical practical lighting, then that's a different story.

Do you know what I mean?

Thanks,

D/
Click to expand...

I'm not sure that i would say that this is the best example of a low light shot- the lighting set up was nothing all that fancy or extreme- so it does show what you can do with a very basic lighting kit.

Here is what I was using:

Key Light / Top light: 250w Lowell pro light (at about 4 - 5 feet above the glass)
Fill Light: 500w china lantern (about 5 - 6 feet away)
Bottom Light: 500w lowell v-light (To light up the rest of the plastic plate)
Background light: 500w smith & victor light with a Steel blue gel bouncing off of a white card that is in the background.

The cup and chess board sit on top of a piece of 250 diffusion, ontop of the plastic plate. Underneath the plastic plate there is a sheet of 216 as well as some white tissue paper.


The first to cup shots were shot at 48 fps and 60fps. All of the chess shots except for the last two were shot at 60p as well. The last two were at 24 fps.

Hope that helps answer some questions. :)
 
Last edited:
TimurCivan said:
The corners are soft!? Ryan try the rez charts again with a different lens. make sure its not the lens itself causing the corners to go soft.

Also, the shutter speed test looked good. looks like youre safe till 1/250th.
Click to expand...

The lens that i have instant access to is just a basic 50mm 1.8- it is nothgin fancy or all that great, as it is a bit soft- I've used some Zeiss lenses that are perfect, and do very well- unfortunately they are not mine, and I have to rent them. I'll see what i can do about getting a hold of them, as they do perform much better.

(I've really gotten into renting gear lately, as it is a lot more affordable to rent it then to buy it all. Although there is something to be said about being able to just pick up and go when ever you want....)
 
Ryan, The most helpful information about the lighting levels is how many footcandles you put on the key if you remember.
Also what was the f stop on the Nikon? Did you try shooting anything at f-stops from 2.8 to 5.6 to look at the grain issue as that's when it may start to come up. That's a very important issue. They all good at very wide open f-stops, but to use a zoom you need at least 2.8 and that can become too much grain on some adapters.
 
Ryan, can you post a shot of ur camera rig with the Extreme attached? That would be uber ace. Also when u shot this footage did u have rails on ur set up?

and disjecta, you posted some footage as well, correct? Did ur rig have rails too?
 
Lenilenapi said:
Ryan, The most helpful information about the lighting levels is how many footcandles you put on the key if you remember.
Also what was the f stop on the Nikon? Did you try shooting anything at f-stops from 2.8 to 5.6 to look at the grain issue as that's when it may start to come up. That's a very important issue. They all good at very wide open f-stops, but to use a zoom you need at least 2.8 and that can become too much grain on some adapters.
Click to expand...

I was just about to take clean the set up, before I do, I'll take some readings- Althought I have an minolta IV F digital light meter- I'm not sure if it does foot candles... I'll look into it ...

As for the camera settings- the HVX was at f2.8 and the Nikon lens was at f4.
 
jigga420 said:
Ryan, can you post a shot of ur camera rig with the Extreme attached? That would be uber ace. Also when u shot this footage did u have rails on ur set up?

and disjecta, you posted some footage as well, correct? Did ur rig have rails too?
Click to expand...

I'll see what i can do- I have longer rails on order, as the cavision ones I have are not long enough right now, so I do not have it attached to the rails.
 
disjecta said:
I started a new thread with some pix of my setup:

http://www.dvxuser.com/V6/showthread.php?p=1057034#post1057034
Click to expand...

Looking good D :).

Here is a quick pic of my lighting setup as well as the camera setup, nothing pretty, but it is getting the job done. I can't wait until the rods get here and I can actually use my matte box, filters and follow focus .... I miss them ...

Lights.jpg

LetusEnhancedRig.jpg


No I'd better get back to cleaning up....
 
Well this is all very interesting information. Thanks for your efforts and you willingness to share Ryan. Alot of people are watching your tests carefully.

Am I gathering correctly here that you saw no grain in footage that was exposed with the Nikon @ f4? And this is shot using a Canon?

What kind of monitor are you using to evaluate these issues BTW?

One last question if you don't mind. I was wondering what f stop your camera would record the same scene at the same exposure both with and without the adapter.

I became skeptical about the claims that one adapter or another only lost 1 stop or a half- stop after the Redrock came out last year. That was supposed to lose less than a stop, but when I got one it was sometimes losing 2 stops. Turned out they weren't measuring that loss in the same way I was. In fact its hard to measure lighting levels and f stops with these video cameras because response is often not linear.
Try to compare the difference between holding an N6 in front of your video camera and changing 2 f-stops. It might be different wide open from somewhere around 5.6. At least that was my experience with the HVX.

So to clarify - say with a nikon lens at f2 and your video camera wide open in low light:
What would the f stop be on your naked video camera ( no adapter) to get exactly the same exposure? That's practical information about how fast the adapter is where it counts.
 
Haven't done a test like that, and frankly it also depends on the speed of your lens -- an f/1.2 lens is going to deliver 3x as much light as an f/2 lens.

However, I can verify that as far as the adapter is concerned, it loses 1/2 stop (or maybe just a hair more). Definitely less than 2/3 stop in total. With the adapter on, pointed at a lit white surface (and no lens), the camera needs to be opened up 1/2 stop vs. the raw lens pointed at the same scene.
 
Lenilenapi said:
Well this is all very interesting information. Thanks for your efforts and you willingness to share Ryan. Alot of people are watching your tests carefully.

Am I gathering correctly here that you saw no grain in footage that was exposed with the Nikon @ f4? And this is shot using a Canon?
Click to expand...

The grain starts to become noticable when you have underexposed the image too much- but that is true of all of the adapters. I have provided still frames of the stuff I shot at full resolution in the link at the start of this thread. So you can evaluate for yourself if you are happy with the results.


Lenilenapi said:
What kind of monitor are you using to evaluate these issues BTW?
Click to expand...

I am using my 23" Apple Cinema display.

Lenilenapi said:
One last question if you don't mind. I was wondering what f stop your camera would record the same scene at the same exposure both with and without the adapter.
Click to expand...

Lenilenapi said:
What would the f stop be on your naked video camera ( no adapter) to get exactly the same exposure? That's practical information about how fast the adapter is where it counts.
Click to expand...

The adapter itself looses 1/2 of a stop, then the lens that you put on looses additional light, so it depends on the speed of the lens that you use. A 2.8 lens looses more light then a 1.8 lens for example. If you have a really slow lens, like a 3.5 for example, you will be needing a lot more light....

With the Letus Extreme, and the Nikon 50mm 1.8 lens attached I am loosing a total of just over one stop.
 
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