My Letus Extreme Experience – bottom line: disappointment due to softness

M

mbradley

Member
Sorry for the long post, but thought my experience might help someone.

I bought the Letus Extreme for one purpose - to achieve shallow depth of field while shooting interviews. Prior to purchase I tried to do my homework by reading this forum and a couple of others. Felt like I knew most of the issues and considerations.

Being a plug & play type guy (I want to use equipment, not fritz with it), I took the plunge by buying a Cine Kit (Letus, rails, camera platform, etc.) from Zacuto. Yes, it is pricey, but it’s also extremely well made and offers versatility for use with other cameras and just about any 35mm lens.

First results of studio testing using a Canon XHA1, the Letus and an old Nikkor 105mm F2.8 were soft. I tested the Nikkor lens with a still camera (newspaper classifieds taped to a wall) and it turned out that this lens was surprisingly soft at F2.8. During a 25 year career in still photography, I’ve tested a number of lenses and have an idea of what to expect. So…

I bit another bullet and purchased a Nikkor 85mm F1.4 from KEH. Quite a piece of glass! I immediately tested this lens with the still camera. You could see some sharpness fall off going from F2.8 to F2.0 to F1.4. A little disappointing but not surprising at these wide apertures.

As time allowed the last two weeks, I’ve tested and tweaked the Letus using the 85mm lens, determining sweet spots for the Nikkor lens aperture (F2.8, F2.0), sweet spots on the Canon both for focusing the Letus’ ground glass (per information I learned on this forum) and aperture selection (F2.8), all while using a JVC DT-V24L1U 24” Broadcast LCD monitor for viewing results after importing into Final Cut Pro.

Lastly I shot essentially the same footage using the same Canon camera but without the Letus - on a different day with slightly different lighting - but close enough to call it apples to apples. And that’s when my opinion of the Letus started to go south.

I immediately noticed when shooting without the Letus, how much sharper my subject’s eyes appeared on the Canon’s LCD, and how much easier it was to focus on them. When compared on the JVC monitor, the clips shot without the Letus were undeniably sharper than those shot with.

Now I admit to being a perfectionist when it comes to image sharpness. In the professional photographic realms I’ve explored over the last quarter of a century, if you don’t have a sharp photograph, then you don’t have a photograph. No doubt many, if not most people, when shooting 35mm adaptor footage in real world situations, would probably not notice the sharpness difference that bothered me.

But when it comes to video interviews – essentially a portrait session with audio – sharp rendition of the speaker is critical. The face, and especially the eyes have to be dead on. No room for error or compromise. If there’s a desire for subject softness, then it should be controlled with filters, not dictated by equipment limitations.

I’ve tried to be meticulous with these tests, but I may be overlooking something. Or perhaps my expectations were too high. Common sense suggests that there may be some price to pay by putting all that stuff (including a vibrating ground glass) in front of the XHA1’s excellent lens.

I’m disappointed; I wanted the Letus to work. I emailed Hein at Letus prior to posting this and he replied, saying he thought the EX1 Optimization Kit might help and offered to send one, with my returning the original achromat for credit. I declined, feeling that I’ve spent enough time with experimentation.

I welcome any further insight or suggestions.
 
Yeah, any adapter will make the image softer because it's adding more glass in front of already existing glass.

I think the first suggestion would be to move up from the A1 to the H1 which will allow you better control of your DOF, there you'll have a choice between using Canon glass or a relay with Nikon lenses.
 
Please post some footage or stills that shows this softness so we can give some insight.
 
Matt, I think you don,t need a 35 mm adapter. For your purpose, you would have to use a video lens teleconversor atached directly to your camera to increase the shallow depth withouth any artifacts. I use a Century 1.6X with my DVX 100 to shoot interviews, and the results are very nices for me.

Luis

........................................
Tenerife, Islas Canarias
 
Sorry , I wanted to say "... use a video lens teleconversor atached directly to your camera to decrease the sallow depth"

Luis

........................................
Tenerife, Islas Canarias
 
Please post some stills, because it sounds like something is not right. I had the same combo and the image I got was very comparable to the stock lens in terms of sharpness in my opinion.
 
That's very strange to hear. Softer images are expected when using a 35mm adapter, but this is generally a good thing that takes off the harsh edges of HD videos. The Letus/A1 combo is particular is excellent in term of sharpness. On my last projects I shoot wide open most of the time on my 135 mm f2.8 FD and 50mm f1.8, and the resulting image was still very sharp. Are you properly focused on the GG?
 
I think you may have a problem with your GG focus.
Here is a standard def, compressed still from a film we shot for school. Looks very sharp in my opinion.

03fa5.jpg


You should see it in movement, fantastic!

and here is one that is minorly soft. Also a slight movement which doesn't help the blur factor, but still very sharp in motion.

92662485og8.jpg
 
It may be the glass your using. If sharpness is paramount, consider Zeiss ZF's and/or Voigtlander and Sony EX 1. The zeiss are really in a different league than Nikon in terms of sharpness. As is the EX 1 compared to the HVX. At wide open at a 1.4 the Zeiss has the sharpnes of the Nikon 85 1.4 at a 2.8-4.0. Dial the Zeiss up to a 4.0 and the sharpness is breathtaking. The only exception with Nikon are the Nikon Zooms 80-200 2.8 and the 17-35 2.8. Though zooms, they are just as sharp as the ZF's. Stupid sharp. The problem with these zooms is the narrow focus draw. But if you're doing interviews mainly they should be fine.

Take a look at the following grabs. Both are from a Nikon 80-200 the first set at 2.8 (wide open) at 80mm and the second 135mm at a 4.0. These are considerably sharper than anything I've achieved with the Nikon Primes and shot with the non-optimized LEX on an HVX at 1080p. This is comparable to the sharpness you'd get with ZF's or Voigtlander. I just ordered the optimized LEX and Hien is making an adaptor to be able to use it both with the EX and the HVX. These grabs are sharp enough for prime time.

Adaptors with the wrong glass are depressingly soft. With my 85 1.4 it's the equivalent of a promist 1 filter. It's not as sharp as the hype would have it. Take a look at Ryan Walter's tests with the 50mm Nikon, 50mm ZF and Red 18-50mm. Very eye opening. Nikon comes dead last. The rez loss with the ZF is about 10 percent.

Here's a link of a video we shot with an SG pro Nikon Set. The macro shots of the eyes are Nikon 105 2.8 (very sharp lens): http://www.timnaylor.com/megan.html

Here's another link of PS technik / Zeiss Super Speed Set: http://www.timnaylor.com/musicvid_richiespicevideo.html. In this case the rez loss with the adaptor is neglible. The link is Varicam down rezzed to dvc 50 transcoded to H 264. I know this is in a different league budget wise but does underline the importance of glass.

Here's one more link: SG Pro with Nikons (25 2.0, 35 1.4, 50 1.4, 85 1.4, 105 2.8, and 135 2.0). It's definitely a softer look. Client in this case loved it: http://www.timnaylor.com/cezar.html

This last one is Varicam - 720 p downrezzed to H 264. PS tech/Zeiss Superspeeds. Again the glass makes a huge difference: http://www.timnaylor.com/vid_deleon.html

I believe with ZF's and the optimized LETUS you could get dazzling sharpness and even to another level with the EX 1. For interviews, you can't beat an adaptor. I'd take it any day over an extender. Comparing the two is apples and coconuts. You can get the dreamy bokeh and short DOF without flattening a face like it's been hit with a frying pan. Extenders on a 1/3" camera will definitely add pounds, shrink the nose and make the ears go by way of Dumbo with the wrong face. Not a good look.
 

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ah, thats why you're grabs seem that much sharper. I mean the lens obviously helps, but i shoot at ( making a correction )
-9 to get rid of all the edge artifacts.

Great grabs though man.
 
Wow Tim. Those grabs just look sharp as a tack. I think this has put me over the edge. Got to go check some pricing to see what it would take to get me into the adapter game with some nice glass... I promise not to post any Letus vs SGPro vs Redrock vs Brevis threads :)
 
Thanks to all who replied. Some good information.

Unfortunately I don't think my issue was with the ground glass focus. I played with that quite a bit while watching the results on a 46" Sony XBR HDTV.

So that pretty well leaves the Nikkor 85mm lens. During my video tests I didn't try any F-stops smaller than 2.8, as I was already at 1/15th shutter speed, and that was while using a studio softbox to supplement the light!

Tim, thanks for the lens information (and nice website, by the way). I know that Zeiss has always enjoyed a cult following with their optics, and probably for good reason.

I am heartened by the success others have had with their adapters. Obviously, shallow depth of field and sharp focus can coexist. But they come at a price.
 
Tim Naylor said:
It may be the glass your using. If sharpness is paramount, consider Zeiss ZF's and/or Voigtlander and Sony EX 1. The zeiss are really in a different league than Nikon in terms of sharpness. As is the EX 1 compared to the HVX. At wide open at a 1.4 the Zeiss has the sharpnes of the Nikon 85 1.4 at a 2.8-4.0. Dial the Zeiss up to a 4.0 and the sharpness is breathtaking. The only exception with Nikon are the Nikon Zooms 80-200 2.8 and the 17-35 2.8. Though zooms, they are just as sharp as the ZF's. Stupid sharp. The problem with these zooms is the narrow focus draw. But if you're doing interviews mainly they should be fine.

Take a look at the following grabs. Both are from a Nikon 80-200 the first set at 2.8 (wide open) at 80mm and the second 135mm at a 4.0. These are considerably sharper than anything I've achieved with the Nikon Primes and shot with the non-optimized LEX on an HVX at 1080p. This is comparable to the sharpness you'd get with ZF's or Voigtlander. I just ordered the optimized LEX and Hien is making an adaptor to be able to use it both with the EX and the HVX. These grabs are sharp enough for prime time.

Adaptors with the wrong glass are depressingly soft. With my 85 1.4 it's the equivalent of a promist 1 filter. It's not as sharp as the hype would have it. Take a look at Ryan Walter's tests with the 50mm Nikon, 50mm ZF and Red 18-50mm. Very eye opening. Nikon comes dead last. The rez loss with the ZF is about 10 percent.

Here's a link of a video we shot with an SG pro Nikon Set. The macro shots of the eyes are Nikon 105 2.8 (very sharp lens): http://www.timnaylor.com/megan.html

Here's another link of PS technik / Zeiss Super Speed Set: http://www.timnaylor.com/musicvid_richiespicevideo.html. In this case the rez loss with the adaptor is neglible. The link is Varicam down rezzed to dvc 50 transcoded to H 264. I know this is in a different league budget wise but does underline the importance of glass.

Here's one more link: SG Pro with Nikons (25 2.0, 35 1.4, 50 1.4, 85 1.4, 105 2.8, and 135 2.0). It's definitely a softer look. Client in this case loved it: http://www.timnaylor.com/cezar.html

This last one is Varicam - 720 p downrezzed to H 264. PS tech/Zeiss Superspeeds. Again the glass makes a huge difference: http://www.timnaylor.com/vid_deleon.html

I believe with ZF's and the optimized LETUS you could get dazzling sharpness and even to another level with the EX 1. For interviews, you can't beat an adaptor. I'd take it any day over an extender. Comparing the two is apples and coconuts. You can get the dreamy bokeh and short DOF without flattening a face like it's been hit with a frying pan. Extenders on a 1/3" camera will definitely add pounds, shrink the nose and make the ears go by way of Dumbo with the wrong face. Not a good look.
Click to expand...

Tim:

What exactly is an "optimized" LEX?

Dan
 
EX-1 Optimization Kit can be used on an HVX as well and apparently pretty much fixes edge-to-edge issues.
 
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