Well I’m a happy chappy. Took delivery of my second PMW-F3 today so that I can shoot my 3D projects using a pair of F3’s rather than my EX1/EX3. Now I have a working lens converter that allows me to use standard 2/3″ broadcast lenses on the F3 the F3 is fast becoming my default camera for almost everything. So the I took the decision to trade in my EX3 against a second F3. For lenses on the 3D rig I’m going to use DSLR lenses. Today I checked out my Nikon 50mm f1.8’s and these were just fine but my Tokina 28mm f2.8’s are un-useable as the lens optical axis shifts as you focus causing alignment errors, so I need to find some alternative wide angle lenses. I’d really like two sets of Zeiss PL mount Compact Primes, but that’s way beyond my budget. I might try and stretch to a couple of sets of Zeiss ZF.2’s, but I think that for the moment it’s going to have to be a case of building up pairs of lenses as I can afford them.
OK folks. I wanted to see just how well a 2/3″ broadcast lens would work on an F3, but don’t have $5.5k to fork out on one of the Abel adapters. So with a bit of head scratching, a few, lowish cost lens purchases and a few hours in the workshop I cobbled together my own adapter. At first I tried a 2x magnifier but this didn’t quite give me full sensor coverage and was soft out in the corners. With a little more work I took the magnification up to 2.5x and I have clean corners. I’m really pleased with the performance, although one lens element needs changing for a higher quality element to combat some softness when the iris is fully open.
My old Canon J16x8 f1.8 becomes a 24 to 320mm f4(ish) par-focal lens which is actually quite handy. Next step is to make up a power cable for the lens so I can use the zoom servo.
I’m considering trying to find a manufacturer that can make these up for me properly, the converter should cost a lot less than $5.5k
UPDATED: SEE UPDATE AT END!
I won this lens on ebay for the grand total of £44.00. Now for that kind of money you don’t normally expect to get a great deal, but this time I got quite a lot. I certainly got a lot of weight and bulk, this is a big lens. It was designed to work with a Pentacon or Kiev medium format camera with a 6″x6″ frame size. The front element is about 3″ (80mm) in diameter, it’s over a foot long and weighs about 5lbs (2.5kg). One of the things that attracted me to it is the iris which has 19 blades giving a very round aperture, so the bokeh is very pleasant looking. The rear of the lens has a Pentacon to M42 mount onto which I screw a M42 to Nikon adapter ring. Due to it’s length and weight it is vital that the lens is supported. The lens comes with a 3/8″ mounting ring with a 3/8″ to 1/4″ insert.
For the moment I’m using the bracket from a Genus DSLR shoulder rig to support the lens until my new Genus lens support bracket arrives.
So… what are the pictures like? Well at F4 it’s a little soft, but stop it down to f5.6 and it sharpens up nicely. I also tried it with a 1.5x and 2x extender as these will soon show up any lens issues. With both the lens performed respectfully well with the iris at f5.6. Stop down to f8 and the lens really performs very well. Of course with the very small s35 sensor compared to the 6″x6″ that the lens was designed for you are only using the center part of the frame, which always tends to be the sharpest part. While it may not perform as well as the latest state of the art long focal length Canon’s or Nikons, this lens does do a pretty good job and if you only occasionally need a long lens, for the money it’s hard to beat.
UPDATE: To get this lens to work on the F3 I was using a M42 to Nikon adapter. This has a corrective lens in it to enable infinity focus. After playing with this adapter on some other M42 lenses I found it’s performance to be less than satisfactory at large apertures. So I tried the Pentacon 4 again, but this time with a M42 to Canon adapter and one of Steve Shovlar’s new Adaptimax Canon to F3 adapters. The performance improvement was quite noticeable and now I can use the Pentacon fully open at f4 with great results. This really is a rather nice lens.