DV Info Net - Sony 28-75mm f/2.8 on FS100

+1 for the Minolta 35-70mm Rokkor f3.5 fixed aperture.

A stunning lens that was rebranded by Leica as the Leica R 35-70mm f/3.5 VARIO-ELMAR-R. You can find good Minolta ones on eBay for under $100. Use with a decent MC/MD to NEX / e-mount adapter and you are in business. I have three adapters and they all needed shimming to get perfect infinity focus and true parfocal zooming with the 35-70mm but well worth the effort.

Getting back to the Sony Alpha lenses. If you use the Sony LEA2 Alpha lens adapter I think you will find that it will work fine with the FS100 like it does with the FS700. This would then give you the auto focus and iris control functions of the attached Sony 28-75mm lens. No stabilisation though as that is in the body of the Alpha cameras. Not that you want that if on a tripod anyway.

What is good with the Alpha lenses is that unlike Canon EF zooms the Sony zoom lenses have proven to be parfocal and unlike Canon EF glass they DO have a mechanical linkage to the iris so can be manually controlled with an Alpha to NEX mount that has a mechanical linkage and ring giving you that manual iris control. Remembering the one proviso that for these lenses to maintain their parfocal performance most of the aftermarket adapters have to be shimmed as most of them are too short. Making them short guarantees infinity focus but most of them focus past infinity which whilst not a major drama with primes is absolutely not good for a parfocal zoom. This is the type of adapter I have shimmed and used successfully. Shame they are not marked if ‘F’ numbers but I can live with that.

Sony Alpha Minolta AF Lens to Sony E Mount Adapter for NEX NEX 5 NEX 7 MA NEX | eBay

The FS100 sensor is I believe 23.6mm x 13.3mm like the 700 so if used with FF Alpha lenses or any legacy 35mm FF lens is going to give you a crop factor of 1.6 or thereabouts. So your 28-75mm lens in effect becomes 44.8-120mm and this covers most interview lengths quite nicely. I find f4.0 gives your talent enough DOF to move without critical focus errors and yet allows you to isolate them with a nicely diffused background should you wish.

Value for money though is Sony’s APSC lens the SAL 16-50mm f2.8 fixed aperture for around $800.00. Again this is parfocal and fixed aperture which for video is a big plus. Again, as long as it’s used with an adapter properly shimmed for the correct flange back distance. This in effect is equivalent to a 25.6-80mm FF lens. A pretty decent lens for interviews. It’s smallish, short and light and very hard to beat on a price / performance ratio.

http://www.bhphotovideo.com/c/product/819163-REG/Sony_SAL1650_16_50mm_f_2_8_Standard_Zoom.html

I have used the 16-50mm numerous times and have had it up against the Canon EF 24-70 f2.8 MkII and I can see on a chart and in the real world virtually no difference in sharpness or contrast between the two of them. In color rendering there is a slight difference but that is more of a subjective observation / preference. In reality most of the FF lenses have MFT and resolution performances designed for much higher resolution sensors than HD video so not many are really poor performers.

When testing various lenses for the FS700 I put up a test results video on Vimeo. The Sony SAL 16-50mm and the Minolta Rokkor 35-70mm are included in that test.

Chris Young
CYV Productions
Sydney