T.Stops Blog

Sony F3 – sLog Testing


I got sLog yesterday, and i finally have had a chance to test it out a bit.

Below you will see, sLog raw Tiffs, and graded Tiffs. Feel free to DL and grade. For reference, i shot the skin tones at about 35 IRE to Uncompressed Quicktime – 3G 444 sLog, @ 0dB F16, with a 2k Par with double diffusion, and in the shot is a 40w Compact fluorescent. no Fill.

The skin tone is metered at a T16, with the highlight +1 stop, and the fluorescent bulb itself is +9 stops, and the top of the puppy’s head is +3 stops over key.

I am flabbergasted that i can own a camera that has this much imaging power.

Uncompressed TIFF http://www.timurcivan.com/downloads/me_log_1.1.3.tif

Quickly graded on a Davinci Resolve to put some contrast and secondaries in the image so you can see what its supposed to look like.

Uncompressed TIFF [url]http://www.timurcivan.com/downloads/me_delog_1.1.2.tif[/url]

By the way….. 444 IS everything its cracked up to be.

Some extreme lowlight grain testing…

This was lit with 1 single candle. Cooke Panchros @T2.8 @ 0dB on The Sony F3 with sLog.

MIND YOU: when in sLog your sensitvity doubles. So 0dB, is now 1600 ISO, 6dB is 3200 ISO etc…. 18dB is 12,800ISO

They do get grainy, but its REMARKABLY clean considering the ISO.

sLog Raw Out of camera (DL the 1080p TIFF)
TIFF: [url]http://www.timurcivan.com/downloads/0dblog_1.1.1.tif[/url]

0dB Graded

6dB Delogged TIFF [url]http://www.timurcivan.com/downloads/6dbdelog_1.2.2.tif[/url]
6dB RAW LOG TIFF [url]http://www.timurcivan.com/downloads/6dblog_1.2.1.tif[/url]

12dB delogged TIFF [url]http://www.timurcivan.com/downloads/12dbdelog_1.3.2.tif[/url]
12dB RAW LOG TIFF [url]http://www.timurcivan.com/downloads/12dblog_1.3.3.tif[/url]

18dB deLogged TIFF [url]http://www.timurcivan.com/downloads/18dbdelog_1.4.2.tif[/url]
18dB RAW LOG TIFF [url]http://www.timurcivan.com/downloads/18dblog_1.4.1.tif[/url]

Also, just for kicks we recorded log to xdcam, to see if we could grade it. Did not work one bit. Log has to go offboard. Too bad.


Todays Test:

1 Sony F3 w/ sLog update
1 Ki Pro Mini
1 set Cooke iPanchros
1 DaVinci Resolve

Objective, to discover where sLog should be exposed, How it should be treated in post, and what the difference between 709 standard Gammas and sLog in post, and acqusition.

From previous testing the F3 w/ sLog clips to white @ 6 stops over key. Using this information i metered the brightest highlights in each scene to +6 stops, JUST touching the clip point ( or what i thought was the clip point). The dark end of the scale fell to where it fell.

The goal being to see how far down you can drag up the image, and how conservative i have to be with using fill light to maintain an image in the black section of the scene.

OK, So here’s the skinny. You have to expose just as carefully as you would with any other medium. The sLog w/ Offboard capture gives you incredible room to adjust and manipulate later, however like every camera, the closer you get to perfect in camera, exposure wise, the more Oomph your image will have after delogging. That said, 10bit 422 ( and especially 444 capture) gives you and INSANE amount of room to fudge.

For kicks we recorded the REC709 180% LUT as well and tried to match them to see if matching was possible. The Footage can be massaged into a similar looking image, but the highlight quality, grain structure, and shadow retention goes out the window. If you need a very high dynaic range shot with and F3 and dont have sLog, if you at least have a KI Mini, you can get SOMETHING…. it wont be as pretty, but it’ll be there.

These compositions are boring, very boring, but they are carefully chosen. to reflect situations i’ve run in to the last few years, on various shots that have always bothered me and made me wish i had the “Infinite Dynamic Range” as MacGregor so eloquently put it. Well, for the most part, we have that now, at an indie price point. Yes, the Alexa is better…. by about a stop. (when you hit the 13.5+ zone 1 stop actually becomes a lot) but at 1/3 the price, this is terrifying performance. And the fact that i own it, and its paid it self off in 3 months, and i dont have a 70k mill stone around my neck is simply phenomenal.

The thing when shooting sLog thats tricky; it goes against every instinct you have as a DP. You have to under expose, so far down that you think “Theres NOTHIGN THERE!!!!! WHAT THE #$%^ I’M DOOING!?!?!?!?” but use your exposure tools, use your false color, use your wave form. Skin tones stay at 35IRE, High lights on skin @ 40-45 IRE. Dont worry, its ALLLLL there…. The trick is to use spot meter to see how many stops you are from one point to another in the scene. Get a Grey card, light your set, get your highlights to about +6 stops over key, then set the Grey card @ 35IRE with the waveform. You should be set.

The truth is i dont know why, but for some reason, color information, because of the sLog, is more accurate, pleasing, and is retained all the way up to the clipping point. Even 10bit capture on regular 709 doesnt have the same amount of detail in highlights. Its just not retained in the same way. Pay attention to the highlights in the forearms in the “dramatic” lighting shots.

I highly reccomend downloaing the 2gig low compression version to really see in full resolution whats going on, and how Frigging sharp the F3 really is.

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