Recent content by cameramanben

Hi All, I personally find the linear percentages unhelpful beyond just 800% is bigger than 400% is bigger than 100%. Particularly since percentages are sometimes IREs, sometimes real-world reflectances and photographers and camera people pretty much always think in stops. Most charts you see...

Hi All, I'm currently working on an update for LUTCalc, and have uploaded an online version to LUTCalc Testing. I've been playing with the picture profiles in an a7s mkII and had a go at analysing the Cinegamma 3 and Cinegamma 4 curves. I checked my process against the Cinegamma 1 and...

Hi All, I've just posted a major update to LUTCalc - v3.0. Quite a lot of work under the hood, and a few more visible developments. Probably most useful is the 'Gamut Limiter'. When you go from a wide gamut like S-Gamut3.cine to Rec709 the leftover colours can lead to nasty clipping. Gamut...

Hi vilrockerdefer, a big reason for 109% gammas is to keep everything within legal range (0-100%) reasonably close to basic Rec709 - so that things look good on a monitor or TV - whilst expanding the dynamic range of what is recorded. Basic Rec709 only has 2 1/3 stops of headroom...

Hi All, after a pretty busy summer filming, I recently got back into looking at LUTCalc, in the past few weeks I have uploaded several updates. I realised that I hadn't mentioned any here, and since I usually write a post, I thought I'd bring things up to date. With v2.5 I added a 'Black...

Hi All, I've just uploaded a new version of LUTCalc to the lutcalc.net website, GitHub, the Mac OSX App Store and the Chrome Web Store: Run LUTCalc page * New Feature - Print out the Stop vs IRE chart, plus exposure table and IRE / 10-bit values for each stop from -8 to +8. * New Feature -...

lagmandokk, just to add to what the others have said, I've quickly knocked up a chart which gives an idea of the 'shades of gray' per stop for S-Log2, S-Log3 in both 8-bit and 10-bit, plus 8-bit Canon C-Log as a comparable, commonly-used 8-bit log curve. The axis at the bottom is stops below...

Hi All, I've just uploaded some fairly substantial updates to LUTCalc to the online 'testing' version. Link here: LUTCalc Testing A couple of the new bits have needed some significant shuffling around under the hood, so I'm not quite ready to release it as an update and I'd really appreciate...

I'm just double checking the measurements, but to get an idea of how smoothly things mapped out, here is a picture of my provisional measurements for Osmo X3 D-Log at ISO 100:

Hi All, this thread should really read 'The World's Most Expensive Lightmeter' - MLUT. The LUT's free, the camera to bung it in, the expensive bit! ;-) I recently bought myself a DJI Osmo, and one of it's options is to shoot what is listed as 'D-Log'. The thing is, I can't find any tangible...

Hi All, just to let you know I uploaded a new version of LUTCalc the other day. It is up online at lutcalc.net, and it should have come through as an update on the Mac App store and Chrome Web Store. The new stuff is: * New Feature - Hybrid-log gamma. * New Feature - All Sony Hypergammas...

Here is a new jpeg version of the pdf, including the charts:

Hi All, I took a bit of a break from geeking out over Christmas, but then decided to have a go at figuring out all the hypergammas for LUTCalc. I've added them all to the online testing version (LUTCalc Testing), plus recalculated Rec709(800%) with a reverse (to help if you accidentally bake it...

Hi All, I'm a lighting cameraman with a Sony camera and for some time I've had a hobby / obsession developing a tool to let me create MLUTs and grading LUTs for use with log shooting based on manufacturer-developed looks which I can then tweak. I usually post on the Sony F5/F55/FS7 forums but...

Hi yoclay, S-Log2 is defined by: if x>=90 { IRE = 219.0 * (power(10.0, (( (x–64)/(940-64) – 0.616596 – 0.03 ) / 0.432699 )) – 0.037584) / 155.0 } else { IRE = ( (x-64)/(940-64) – 0.030001222851889303 ) / 3.53881278538813 } where 'x' is the 10-bit code value (or...