Guest post by Mick Jones:
Ever since the announcement of the Sony a7S camera at this years NAB show, I had been excited about the possibilities of what it could do. Obviously the full-frame sensor and exceptional low light capabilities make it an attractive camera in it’s own right. But the improved codec (XAVC S) and lack of aliasing really got me intrigued as to how it might cut in with my Sony F55 on a production.
Since getting the a7S I have been shooting with it in various situations just to get to know it, and absolutely loving the results. After putting the footage through post production and checking out the graded images I thought it was high time to get it on a shoot with the F55 as a “B” cam. I think it has a lot going for it as an “A” camera was pretty confident it could be made to work. I’ve been doing some documentary shoots for The History Channel which were completely controlled lighting situations so I thought that would be the perfect opportunity to line them up.
The F55 has been my main camera for the past 18 months so I felt I knew it pretty well. After a checking out the different gammas on the F55 and the different picture profiles on the a7S I found a combo that worked for me. The results were close enough that they didn’t require much work to get the cameras to match in the grade. I did feel that the a7S had a slight magenta hue when compared to the F55 but it graded out easily. Below are the results:
The close up interview shot is on the a7S and mid shot is on the F55. I had the F55 set up to record XAVC internally at 1920×1080/25P. Color temperature was 3200 and the profile was Custom mode with HyperGamma 7 at 1250ISO.
The a7S was on Picture Profile 6 which uses the ‘Cinema’ colour space, I changed the gamma to CineGamma4 but left the rest as is. Colour temp preset selected to tungsten and shot Full frame XAVC S 1920×1080 at 25P, 1250ISO.
The a7S had a Canon 70-200 F4 L lens mounted that was set at f5.6. The glass on the F55 was a Zeiss ZF 50mm 1.4, also at f5.6.
I found that in this lighting setup at the same ISOs and apertures I was getting a pretty close match on the luminance levels between the two cameras.
I usually shoot with S-log 2 or 3 on the F55 so my next step is to see how I can get that to cut with the a7S version of S-log. You might expect S-log 2 on the a7S to look exactly the same as the S-log 2 on the F55, but after initial testing I feel that it is actually quite different. In particular I feel the blacks are lifted significantly in the Slog 2 on the a7S when compared to the F55 – but I need to take a closer look at that. That said I’m sure they they can be made to play nicely together in S-log mode as well.
Considering the price difference in the two cameras I think the a7S is amazing bang for buck and the fact that I can confidently use it to seamlessly get another angle on a F55 shoot is just amazing. I think I will end up with a second a7S body before the month is out.