|Posted: Tue Feb 07, 2017 12:39 am Post subject: Please help me choose 25mm lens for anamorphic shooting
|I own a Blackmagic micro cinema camera, and ISCO S8/2x Anamorphic attachment that I use to make videos.
Currently I'm finishing my first project, my setup looks like this: BMMCC (super 16 sensor), 28 2.8 C/Y Distagon, ISCO S8, SLR Magic Rangefinder.
The image that I get out of it is nice, I like how sharp Distagon is, but there are several things I think I can improve with choosing more suitable lens.
First – several times I have encountered situations when I could use quite a bit more light, and f2.8 is somewhat slow to be frank.
Second – I am cropping all my footage from 3.5 to 2.6 ratio, so a little vignetting would not be a problem, and I can go down to 25mm and get just a bit more of that precious vertical FOV.
Third – get a bit more "character". I'm not sure about this one, but I occasionally enjoy the swirly bokeh of Petzval-type lenses.
So I am looking at various 25mm lenses, C-mounts and other mounts from 16mm cameras, but also looking at Speedbooster+35mm lens options. I know speedboster can get you a +1 stop of light, and that's one of the main reasons why I want to change the lens.
So here are things I'm looking for:
1. As much light transmission as possible, for a reasonable price. I have seen 0.78 and 0.85 C-mount lens, but am not sure how much light will they let through, compared to more common and cheap f1.4 stuff.
2. Shallow DOF with a so-called "3D pop" effect. I am not sure how big the difference between 0.78 Canon, 0.85 Fujinon, 1.1 Switar and all the rest 1.4 lens would be. The sensor that I'm dealing with is pretty small, and getting shallow DOF is quite hard, so I will value the smallest differences. Also various lenses render volume differently, and I'd love to know your opinions about what you're using.
3. Sharpness wide open. I don't expect anything to be as sharp as the distagon, but would appreciate if it's close.
4. As small entrance pupil as possible – the rear element of the anamorphic attachment is around 30 mm, so anything less then that should work, preferable 20-25mm entrance pupil.
5. Front glass close to the edge of the lens barrel (not super deep inside like some cine lenses out there have) – so I can mount the anamorphic as close to the glass as possible.
6. Front threads of that will take common stepping rings.
I would appreciate any opinions or help, I have never owned any C-mount glass and would appreciate thought from those, who did.