August 30th, 2010, 06:52 AM
So I just bought a Letus 35 Extreme with a Nikon Lens attachment to go with my Canon XL H1. I could never get the shallow DOF with the 6X Wide Canon lens so that is something I'll definitely want to enjoy with the Letus35. The only things I want to shoot with the Letus35 attached are my indie noir films which are tight quarters, usually never wide. What is a good Nikon lens for that purpose? I've got a couple DX lens's for my wife's D60 (18mm-55mm and 70mm-200mm IIRC), but from what I read those are near impossible to get working well.
Also I'm not sure it goes here or not, but rails are highly recommended correct? Are the Letus V2 Rails good? In addition I take it a matte box is also recommended? Any suggestions on those with my setup? With all of the added weight, I'm also thinking a new tripod might be necessary, I've got Davis & Sanford ProVista with the V12 head, should I keep with the tripod and upgrade the head to the FM18 or just upgrade the whole setup? I'm only looking to spend around $600 for the tripod.
September 9th, 2010, 02:15 AM
I have only used the Letus Extreme/Letus version one rails onto the Sony Z1, Sony EX1 and SI2K Digital Cinema camera.
Letus V2 rails are custom to the Letus adaptors.
I understand Zacuto did their own rails system for the Letus Extreme/Elite/Ultimate adaptors.
I would certainly recommend rails. There is otherwise far too much mechanical stress placed on the lens/camera junction which may translate into a image which moves about with handling of controls, focusing and also may do damage to the camera if unsupported.
Nikon film stills-camera f1.8, f1.4, f1.2 lenses are recommended. Digital lenses cover a smaller image area and there may be corner brightness falloff or even a vignette. Here is a link to an old clip which shows the image from a DX digital stills lens, the Nikon f4 12mm-24mm zoom at 12mm wide-open and other film still lenses.
The 14mm f2.8 Sigma lens is described as digitally optimised. From memory the groundglass image area I was using was about 24m - 28mm wide. You may get a wider area on the Letus Extreme depending on how central to the camera sensor the image fall is.
A lens aperture of f5.6 is the generally accepted limit of 35mm groundglass adaptors. If you choose a lens such as the digital Nikon f4 12mm - 24mm zoom, there remains only about 1.5 stops before the wall is reached beyond which groundglass artifacts may appear.
Most users will not recommend routinely shooting with fast lenses fully wide-open just because one can.
Stills lenses over the last f-stop to fully wide may flare or lose sharpness. What the fast lenses enable is useful apertures in the region f2 - f4 where the lens can be expected to be performing within its "sweet spot".
Apertures of f1.8 or wider yield a very shallow depth-of-field. Whilst novel for the first-time adaptor user this is not so practical in real world work, especially if dynamic subjects, camera moves and focus pulls are involved.
Hopefully, someone better qualified than I will chime in and put you right on what is best.