What I learned today.... at DVinfo.net

Go Back   DV Info Net > Special Interest Areas > Alternative Imaging Methods

Alternative Imaging Methods
DV Info Net is the birthplace of all 35mm adapters.

Thread Tools Search this Thread
Old September 24th, 2006, 12:04 AM   #1
Regular Crew
Join Date: Jan 2006
Posts: 85
What I learned today....

Well, several things:

1. Bob Hart knows wayyyyy too much about light and imaging.
2. Quyen is a good person to listen to about the Letus35A, he builds them after all, fancy that!
3. Focus pulling is a VERY difficult job.
4. Sachler's $25K tripod must be worth the money

So... a week or so ago I started futzing with my new Letus35A and some Canon FL lenses.


My early results left a little to be desired (to say the least) but with some good advice from Bob and Quyen I ventured out again today (minus 3 diopters and armed with some great info about setting up my Sony HVR-A1U.

Can't say I am 100% happy yet but I am getting there. My Sony lacks true manual aperture control, so instead I opted to set the shutter speed manually at 1/60th, and controlled the light via ND filters and the Canon Fl's iris. Still getting what looks like a slightly over-exposed image but I think I know what to do next to improve that.

I was using a Canon Fl 85mm f1.8. I am quickly learning that even a moderate focal length like a 85mm picks up every little movement. Think I'll go back to my 50mm f1.4. next week. Note, the pics below show my my camera set-up on a small Varizoom steadicam, which I did use last week but this time around I was using an inexpensive tripod.

Ben Winter also just sold me his Century Optics achromat, so I am looking forward to using that inplace of the standard Letus one. I observed chromatic aberations today (yellow and purple fringing) in the expected high-contrast areas, particularly in the out of foucus parts. I am hoping that the CO achromat and using the 50mm but not completely open-wide (like I was using the 85mm) will nail that.

Well, here's the updated page with clips:


Last edited by Paul Ramsbottom; September 24th, 2006 at 01:40 AM.
Paul Ramsbottom is offline   Reply With Quote
Old September 24th, 2006, 01:42 AM   #2
Join Date: Jun 2005
Location: Hollywood, CA
Posts: 1,675
Images: 1
It looks like you're blowing out your diffuser. You'll achieve sharper and more saturated footage if you step down the iris on your SLR lens.
Ben Winter is offline   Reply With Quote
Old September 24th, 2006, 07:05 AM   #3
Inner Circle
Join Date: Dec 2003
Posts: 4,364

If you can hold the camcorder's automatic video gain to 0db with a manual setting, you may be able to get the image darker without bringing up video noise by auto gain digging deep to compensate starving the camera for light.

Ben suggests the diffuser image is blown out. This could well be.

A smaller aperture or ND gel on front of the SLR lens or in the space between the SLR mount and the dust glass on the Letus35 will help. Make sure your Letus35 model has a dust glass in there. The flips have it but I don't know if the non-flip versions do.

If you can't get ND gel, a trip to your local flower seller to scrounge some blue, red and green cellophane bouquet wrapper, stacking three colour layers and shooting through it after doing a white balance will be a dirty and likely colour abberant way of getting ND.

Another trick might be to shoot a test in early to mid morning or mid afternoon to late, with sun behind you and placing a small overbright object in the shot to fool the camera into limiting gain.

I can't see your clips as my computer doens't have Quicktime. If I could get a small clip, say 5mb as a half size frame downloadable or as an email attachment VideoLan will open it for me and my email computer will play it as ancient as it is.

I don't take downloads to the editing computer. I try to quarantine it from virus type mischief.
Bob Hart is offline   Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

(800) 223-2500
New York, NY

B&H Photo Video
(866) 521-7381
New York, NY

Texas Media Systems
(512) 440-1400
Austin, TX

Precision Camera
(800) 677-1023
Austin, TX

(800) 323-2325
Mineola, NY

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Special Interest Areas > Alternative Imaging Methods

Thread Tools Search this Thread
Search this Thread:

Advanced Search


All times are GMT -6. The time now is 05:53 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2018 The Digital Video Information Network