Some Letus HD100 Footage

[Jim Giberti]

I finally got a chance to post a little footage from the Letus HD100 I had Quyen build me. I can't show any of the production work we're doing with it, but I did some quick shots around the farm and tried to show different DOF, and looks versus the stock lens. Kris will definitely not be happy with me for posting her after a day of hiking.

http://homepage.mac.com/jimgiberti/FileSharing5.html

[Jemore Santos]

Jim it's not loading.

[Werner Wesp]

No indeed, it's not...

[Andrew Young]

Hi Jim,

I managed to download it fine. Thank you for posting this - it is some very interesting footage. Unfortunately, the quick cutting and compression makes is a little hard to evaluate sharpness and ground glass noise. Is there any chance you could post a single camera original m2t or Quicktime? If you could, fur or skin would be better then leaves.

Also, I have a few questions: 1) what was your detail setting? Approximately what aperture was used on the Nikon? Do you have a sense of the light loss? Have you use it in low light? Does the relay lens have an aperture setting? If so where was that set? Quyen reports a 1.9x magnification factor in relation to a 35mm SLR. Do you have any sense of what the factor is in relation to a 35mm cine FOV? What sort of motion does the ground glass have. Sorry for so many questions and thanks in advance for any info, Jim.

[Stephan Ahonen]

Originally Posted by Andrew Young

Quyen reports a 1.9x magnification factor in relation to a 35mm SLR. Do you have any sense of what the factor is in relation to a 35mm cine FOV?

It's a bit hard to exactly say because of all the ways of getting a picture on film (anamorphic academy, super 35, 3-perf, etc), as well as the fact that a motion picture frame has a different aspect ratio, but the best approximation I can make is 1.5x or slightly more horzontally and between 1.5x and 2x vertically.

If the Letus is compatible with short back-focus lenses like Canon's EF-S then you should have no problem getting pretty wide. Canon makes a 10-22mm zoom which is designed for digital SLRs having a crop factor compared to film.

[Jim Giberti]

Originally Posted by Andrew Young

Hi Jim,

I managed to download it fine. Thank you for posting this - it is some very interesting footage. Unfortunately, the quick cutting and compression makes is a little hard to evaluate sharpness and ground glass noise. Is there any chance you could post a single camera original m2t or Quicktime? If you could, fur or skin would be better then leaves.

Also, I have a few questions: 1) what was your detail setting? Approximately what aperture was used on the Nikon? Do you have a sense of the light loss? Have you use it in low light? Does the relay lens have an aperture setting? If so where was that set? Quyen reports a 1.9x magnification factor in relation to a 35mm SLR. Do you have any sense of what the factor is in relation to a 35mm cine FOV? What sort of motion does the ground glass have. Sorry for so many questions and thanks in advance for any info, Jim.

Hi Andrew, glad you could get it. Unfortunately I didn't even consider that I would overload the .mac account with a hundred downloads in an hour, so unless I can find another place to upload I can't put up any raw footage right now.

I know what you're saying about the quick cuts and compression. There were a number of people asking about footage and I can't really post any production work, and got some time to shoot some quick personal stuff and edit it together. I did the cuts to give a general sense of nature, people, amimals, motion, pan, tilt, etc., but you're right it's definitely not good for critical evaluation.

As to your questions, here goes:

I did some initial tests with the Fuji lens, Nikon 50mm 1.2 and a Putora chart, tape measure and a Kino to get an accurate sense of light loss and resolution.

Regarding Detail setting, we always shoot at minimum (almost) and I found that by bumping detail to -6 in the above test, I could virtually match the resolution of the HD100 with the Fuji with no digital artifacting. I was pleased not but not shocked by this, having owned a Mini35 since the first generation and working with the folks at ZGC/P&S we agreed that there was an actual bump (on an XL1 and XL2) with the Mini35 and quality primes.

As to light loss, I'd agree with Quyen's assesment of around a stop of loss - but that's my unofficial take.

As you can imagine, it was fading golden hour and I was just grabbing a bunch of things around the farm including moving dogs and horses, so I can't say shot to shot, but the Nikon was probably at f/1.2 and 1.4 most of the time and never beyond f/2.0 except in one quick grab - the tilt down my lower barn with leaves in the foreground and the horse and barn and pond behind. I remember stopping the prime down (not what you do with the Mini35 or Letus in a controled situation) to adjust for the giant bounce of the big yellow barn and with Autumn sun. I put that in there so somone like yourself could see the GG in the move against the solid green roof - that's indicative of the restrictions with the P&S and stopping down the prime against solids like fields and skies etc.

Other than that, it was probably all open to a stop down.

The relay on the new Letus HD100 is a 50mm prime with a continuous iris ring and a 1.7 maximum iris. It "blooms" wide open, gets clean around a stop down and definitely should be set and stay between f/4.0 - 5.6 though it looks good a bit more open.

Again, without an absolute comparison, I'd agree with about 1.9x magnification. With the full set of Nikon primes I'm using with the Letus (20mm - 85mm) I've got an effective 38mm - 160mm.

Can't give an absolute comparison of FOV Letus to a Cine but in our pretty extensive Mini35 comparisons of the Nikons vs a set of Zeiss Super Speeds there was no difference. There's no vignetting with the Letus HD100 and the image is upright.

As to the GG motion, it's a vibrating glass vs the spinning glass of the original Mini35. That was one of the reasons I sold the Mini35 when we started producing all HD, with the intent of getting the new model. We called it the spin of death - the center frame against those solid, light backgrounds I mentioned, when the GG would become apparent if you stopped down too much.

The new generation Mini35 is oscillating, but after reading initial reports of problems with the Mini35 and HD, I figured, for the $ why not have Quyen make me one and see.

Obviously it doesn't have the build of a 10k adapter, but it's really lighweight and easy to mount (the Mini35 would stay on one camera all the time because it's not easy to switch on and off). If the Mini35 build quality is a 10, the Letus HD100 is a 7.5...not bad for under a grand.

I've been jamming with post work since summer and I'm not out of the studios much, but I will have a crew out with this setup this month for a couple of TV shoots and work on a new doc. I'll need to push it more before then to see if it's as absiolutely clean as I know you're wondering.

What I can say initially is that it's every bit as sharp and accurate as the Mini35 was and way better looking on the JVC than the XL2 and Mini35...so that's a good start.

Hope this helps.

[Stephan Ahonen]

Is there a way you can post it using something other than Quicktime? QT's H.264 decoder is incredibly slow on a PC. Something like an MPEG-4 AVI or a WMV would be perfect.

[Jim Giberti]

Originally Posted by Stephan Ahonen

Is there a way you can post it using something other than Quicktime? QT's H.264 decoder is incredibly slow on a PC. Something like an MPEG-4 AVI or a WMV would be perfect.

Nothing I could get to quickly...it took forever to get this up <g>.
I did get an email from a member offering to host the file for a while if others wanted to download it. If anyone was interested I could do that.