Wednesday, July 17, 2013

Sony F55 using Canon FD lenses, Part 4, S-log-2

Yesterday I posted frame grabs from the F55 under controlled lighting situations using both Mpeg-2 and XAVC codecs, and turning the detail and crispness all the way down, and of course, using Canon FD lenses on a FZ to FD adapter. Other settings included were S-gamut and S-Log-2.

Today I'd like to post some exterior frames. Settings for this outing were 1920x1080 23.98p XAVC, S-gamut, S-Log-2, and Canon FD lenses. Again, the point to these tests are to achieve a filmic look with the F55, so this time I turned UP the Master Detail and Crispness to -50, so just half way up from the factory default position of 100.

Later today I plan to shoot my last test that hopefully shows how the various gamma choices (HG and STD) will affect the image.

So here we go! I'll put these frames up small to get them relatively side-by-side and you can click on each to magnify to original size. They will be paired with one frame color corrected using Fast Color within Premiere Pro CC, and the other frame is the untouched S-Log-2/S-gamut original, again, using the -50 setting on both Master Detail and Crispness in the camera's Paint menu.

 First frame up is this bike rider on the bridge, 135mm Canon FD. Left one, untouched log, and the right one, corrected. On all these daylight shots I went for a f4 to f5.6 stop, using either 1.8 ND or .9 ND.

What I like here is how well I can still see the detail of the rider while I exposed to keep the sunlight on the bridge from blowing out, 70% zebras on the white stripes only.

 On the steamboat, left one log, right one corrected (135mm). Again, exposing so the water is around 70% zebras, but we can still see the passenger's details well.

 My wife, Shannon, on the dock (24mm) in log and then corrected. I was kind of surprised how dark the background trees stayed, but dark green is a hard color to bring up in all cameras.

 Closer view of Shannon (85mm) in log and then corrected. Again, skin exposed for just under 70% zebras on the brightest point.

 Shannon closer still (135mm), same exposure, everything in control, love the detail in the hat!

 Here a group of ducks in log, and then corrected, (135mm) so that the white duck is just under 100% IRE. None of these images needed a lot of black level. I mostly brought up the highlights, mid tones and contrast. Still there is detail in the darker ducks further back.

 White swan in log and then corrected, (85mm) exposing the brightest feather with a little bit of the 70% zebras. Water stayed in check after correction.

 Shannon walking with ducks, log and corrected (85mm). What I liked here was that she was in bright sunlight and the ducks were in shade, but still was able to bring up their detail nicely without the sky going white. There is a lot of natural contrast to this scene (again dark trees) so I wonder how well a low contrast filter might do, or possibly one of the hypergamma (HG) settings.

 Moving on to a really challenging night scene, log then corrected, (24mm), f1.9, no ND, we can barely see this image of a guy sitting on a longhorn statue until I bring him up out of the very dim tungsten landscape light. I couldn't even get a proper light meter reading here and set the ISO to 4000, yet the noise level wasn't screaming as I thought it would. It was there, but not crawling. Again, I will post these scenes in motion once I cut together all the sequences I plan to shoot so people can see what the noise really looks like here. I could have shot at a higher ISO but chose to see how much noise gets introduced when brought up from a well underexposed situation.

 This street scene with bus in log and then corrected, (24mm), f1.9, at 4000 ISO was very acceptable for noise. I didn't get a meter reading inside the bus, but was happy to see it wasn't blown out at all, but admittedly the bus destination sign on top is blown out.

 Another street scene in log and then corrected, at 4000 ISO, (24mm) again fairly clean noise level. The neon sign is actually white already, but it didn't get out of hand once the image was brought up in level.

 Last frame is of the Omni hotel in Dallas, (24mm) which has this dazzling display of light on the building. I don't know if it is neon or florescent but it can change color instantly and has an infinite series of animated patterns. Again log and corrected, at 4000 ISO, which seemed like good exposure to see the parking lot below (not in this frame grab) but still not wash out the colors in the building lights.

After I shot all these scenes, I read on a Sony F55 forum that the ideal exposure for the camera is to set the zebras at 59% for skin, which is supposed to put middle grey at 32% IRE using S-Log-2. So according to that piece of info, I technically overexposed my daylight images by about 10%, though I didn't see anything overexposed on those images. So either the camera's latitude is very forgiving or Sony techs are overly cautious about protecting the highlights.

This isn't the first time I've questioned the "ideal" exposure recommendation from Sony. When I was testing the F3 in S-log, Sony says to rate the camera at 1600 ISO in order to make middle grey to fall at 38% IRE, but I felt this was an over exaggerated protection of highlights at the detriment of the mid tones and shadows when brought all the way up in correction. Instead I started rating the F3 in S-Log at 1000 ISO and have never found the camera to lose control of highlights, yet the mid tones and shadows were therefore easier to bring up with less noise added.

I liken this strategy as the approach we DP's often took with overexposing film stock a 1/2 stop or more to reduce grain and provide a nice dense negative. Certainly I'm not advocating any extreme disregard for Sony recommendations and to go ahead and overexpose everything with the F55, but it does seem counter productive to bury the shadows and mid tones so low as to create unnecessary noise when corrected. I think if I had an extreme highlight situation to contend with, I might follow Sony's protocol more stringently, but that is not usually our situation in the field or on the set. How about letting the inherent 14 stops of latitude handle the highlights in most situations? I invite anyone else to chime in on that thinking.

At the end of the day, I found the camera very easy to use. It booted up fairly fast, menus were getting easier to navigate and understand, the battery lasted longer than I thought it would, achieving good images was easy, I liked the OLED VF a lot, and I thought all the images coming from the Canon FD lenses were quite good and fairly filmic looking. I wouldn't hesitate to use those lenses on an every day bases to achieve a filmic look. I'd like to try some Cooke lenses as well.

Tomorrow I'm going to post some shots I took last night on our patio that might be a good low light noise test in the blue color range. Stay tuned and thanks for checking this out. Feel free to comment!

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