Prime lens for Viper Filmstream
Posted 24 February 2010 - 11:25 AM
My company is planning a shoot in late March, using Thomson's Viper Filmstream. It is a B4 type mount, 2/3 CCD, and one we will be using currently has mounted an Canon HD-ED HJ9 8x zoom (5.5 to 50mm).
However, the producer is interested in tracking down a set of primes for rental, for the sharpness and greater speed.
I've found a few examples, like Canon's FJ line, and Carl Zeiss Digiprimes, but the rental houses for these products are all largely coastal, and we're located in KC. It would be nice to find something closer to home.
The next possibility is adapting some S16 or 35mm lenses to B4, but I understand that for some lenses (such as those with PL mounts), this could prove troublesome (in another thread, it was stated PL to B4 could yield focus issues).
Any advice on new avenues to consider would be really appreciated!
Posted 24 February 2010 - 04:36 PM
Have you tried contacting Zeiss distributor Bandpro and asking them who has Digiprimes for rent in your region?
Their number is: 818.841.9655
Posted 24 February 2010 - 08:34 PM
If you're stuck for ideas: digiprimes.
Edit: the issue with adapting PL mount lenses onto 3-chip cameras is that they don't necessarily, or possibly even often, have light rays coming out of the back which are parallel to the optical axis (strictly, they are not image-space telecentric). This can lead to convergence issues between the RGB imagers.
Though frankly, I have seen it done, and it was not unusably terrible; they suffered perhaps more badly than usual from magenta-green bokeh but that's a completely subjective assessment. You could probably get away with it if you carefully assessed the performance of a particular set of lenses in this regard.
Posted 25 February 2010 - 11:11 PM
Luckily, a place we've rented from in Chicago carries them, so it looks like we'll get a good arrangement.
Posted 26 February 2010 - 02:12 AM
If you go with Zeiss, make sure to also rent the Zeiss Sharpmax collimator. It's a tube that slides onto the front of the lens and projects a Seimens star so you can check back focus quickly at infinity focus. Much faster and more accurate than throwing up a focus chart as you don't have to pull out your tape measure and move the c-stand back and forth, it's well worth the extra rental cost. Do it for every lens change if possible.