Sony NEX-EA50 vs. Sony NEX-FS100 (and the Parfocal 3x+ Zoom Challenge)

It has been 14 months since I last used a video camera with a servo zoom lens. I wasn't sure if I would be able to go without a servo zoom lens, or a lens that has more than 3x zoom and has a constant aperture, but when I saw the image quality coming off of a Sony NEX-FS100 that I was reviewing, I knew I would have to find a way to do without a servo zoom. I bought two FS100s.

I wasn't the first videographer to ditch the servo zoom--with so many companies ditching video cameras in favor of DSLRs, I figured it couldn't be that hard. I probably made things harder on myself than I needed to by refusing to buy the Sony E-mount 18-200mm f/3.5-5.6 OS kit lens (SEL18200), that is the only lens that many FS100 shooters own, but I found it hard to get excited about an f/5.6 lens (at full telephoto) when there were so many great fast primes and 3x parfocal f/2.8 zoom lenses.

So I set off to find the best zoom lenses that I could for the FS100 and decided that I wanted to stick with A-mount lenses, which include Sony Alpha and legacy Minolta AF and Konica-Minolta AF zoom lenses. I settled on a three-lens kit of the Sony 16-50mm f/2.8 DT, Konica-Minolta 28-75mm f/2.8, and Minolta 70-210mm f/4.0 lenses. Then I added a pair of Minolta MD Rokkor prime lenses--the 50mm f/1.4 and 28mm f/2.0--although I just ordered a manual E-mount Rokinon 24mm T1.5 Cine Lens in the hope it would match my 50mm 1/4 lens better.

Sony EA50 with no sensor zoom on Minolta Rokkor-X 50mm f/1.4 prime lens at F/1.4.

Happy with my 3x zoom and prime collection, I set out to find lenses that are longer than a 3X zoom, maintain focus when you change focal length (parfocal), and have a constant aperture so my F-stop doesn't change when I zoom in or out.

Zooming Past 3x

This last lens challenge has proven to be the most challenging. I found on some shoots that I wanted a zoom lens with more zoom range than the 3x ones that are in my kit. After a ton of research I bought a Tamron 24-135mm f/3.5-5.6 and a Sony 18-135mm f/3.5-5.6 DT lens. The Tamron claimed to be parfocal but really wasn't, and Sony made no parfocal claims but was.

So I celebrated a little victory that I had found a new parfocal lens. And then I decided to check to see if the lens could hold an f-stop throughout the entire zoom range and realized that there was a problem--these lenses couldn't hold an F-stop through the entire zoom range, and even if I stopped down the lens to f/5.6 when fully wide, it stopped down even further as I zoomed in. There was no way this was going to work. I could handle the f/1.6-2.0 that my Sony Z7U used to do, but 1 1/3 stops was too much loss of light.

So I asked my brother--a fellow videographer owns an 18-200mm E-mount--what he did, and he told me that he stopped down the lens to f/5.6 before zooming in and the lens held that aperture through the entire zoom range. I retested this on my A-mount lenses and confirmed that they were not able to hold aperture this way. I can't explain how or why the Sony E-mount kit lens is able to do this, but it's nonetheless an attractive feature--and yes, that lens is parfocal. I added the E-mount kit lens to my wish list, but knowing what was on the E-mount lens roadmap, I held off buying one.

Enter the Sony EA50

Sony had already hinted when the NEX-FS700 was announced at NAB 2012 that an E-mount servo zoom lens was on their roadmap--the zoom rocker on the FS700 was the tell--but no details were given. Sony then announced the NEX-VG30H and NEX-EA50H (H denotes they include a kit lens) and both models included a new kits lens, the Sony SELP18200 (The P denotes a Power Zoom), and this lens caught my attention. So did the EA50, as Sony claimed it was able to perform a 2x lossless zoom on the sensor.

Sony EA50 with 2x sensor zoom.

As luck would have it, my local Sony dealer, Fusion Cine, was scheduled to speak at the BC Professional Videographers Association meeting last Wednesday and they brought two EA50s with them. I took one back to my studio and had it for a day and a half before I got the call that Sony needed their demo unit back for a show in Calgary.

What makes the $3,600 Sony NEX-EA50 unique is that it is the first large-sensor video camera available with an integrated shouldermount. If you've ever tried to hand-hold a large-sensor video camera without a rig you know that it's virtually impossible. The top placement of the LCD on my FS100s has cost the ability to spontaneously go handheld. In general, I found that with the kit lens, the EA50 was a bit front-heavy, but Sony has two screw mounts on the shouldermount slider (which you can retract for tripod use) if you want to add weight or accessories.

I don't own any E-mount lenses, so I never benefitted from the in-lens Optical Stabilization (OSS) that is required for hand-held or shouldermount work, but as I usually stick to tripod, slider, and crane work, I didn't miss this much. The OSS works very well, but--like all stabilization systems--you need to turn it off when you're working on a tripod or your starts and stops won't be crisp.