Letus 35mm adapter focus problems

R

RossS

Active member
Here is a copy of a letter sent to Quyen. If anyone has an answer or advice, I'd love to hear it.

Quyen,
Went to begin shooting with my Letus35 Flip Enhanced today with disastrous results. I was trying to shoot an indoor scene with my DVX100A, Letus35 FE and a Canon FD 50mm f1.4 lens. It’s an indoor bar scene with two subjects talking. I am lighting with an Arri 650w fresnel for the key and an Arri 150w for the backlight. I had my DVX zoomed at about z74 to eliminate the vignetting, but the iris needed to be wide open on the DVX and wide open on the Canon lens to get enough light for the shot. That being said, the light issue was not nearly as bad as the focus issue. At about 10 feet from the subjects, I could not get them in focus, even at infinity on the Canon lens. I tried everything. When I zoomed out on the DVX, the shot looked great, except it was the size of a postage stamp on the monitor (all you could see with the inside of the Letus and a small square of a shot). Can you shed some light on what might be possible problems with focus?
 
Try adjusting the backfocus, by loosening the Canon mount and sliding it a tad away from the body. It's easiest to tell when you have it at the right point by setting focus to infinity and pointing the lens at something that's, well, "infinity" away. When you have it at the right position, tighten down the lens mount and don't let it move again.
 
Thanks Barry. I tried it with the 28mm and it "seems" to work. My lights are at the location and my house lights have trouble generating the candlepower for the Letus, but I could see the difference in nudging the mount back and forth a little.

Barry, do you have any troubles with threading the Letus? When I tighten the unit to the DVX, it is not straight (so the lens is not at the bottom and when you zoom out, the rectangular image is at an angle.
 
Last question, then I'll leave you alone. Do you mainly shoot withthe Letus outdoors, or have you had any success indoors (with the light loss it seems pretty tough unless you have a lot of light!). I'm leaning toward shooting without the adapter when I begin with my doc on Wednesday (scenes on Wednesday are to be shot in a dark bar).
 
Indoors is where you have the toughest time, and the most benefit. I can "cheat" shallow DOF outdoors without an adapter, no problem, but cheating that indoors? Very difficult.

Use a fast lens; with an f/1.8 or faster your effective light loss is 1.5 stops. On a DVX that puts you at just a half-stop slower than a regular HVX, so it's not really that much of a deal. Use proper lighting and treat it as about 200 ISO film.
 
Thanks so much for the advice and for being generous with your time and wisdom (it creates good Karma!).
 
If you can't focus with the 50mm, your never going to achieve true focus with a 28mm either. If you can't focus, it most likely is not the lens causing the problem, unless of course you got a bad lens.
 
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