Levin Liebig

I usually just use toilet paper or something similar to change the bulps. The important thing is that no oil of your skin comes in contact to the glass. Most redheads have a grid in the front preventing shards from the bulb flying into your actors face. (That sounds really bad :huh: but that is not likely at all.) One more important thing is to remember to relief the strain on the cable. So if someone trips over the cable, the lamp will not fall. It will also help to prevent the cable braking where it enters the case of the lamp.

If you choose to underexpose your picture, remember to always put one spot of brightness into your frame. This could be a practical in the background or a rim/shoulder light or something else.

That sounds like a good aproach, Robin. Expose LOG with a rec709 LUT and using the ISO for "over-exposing". Thank you. This might explain our results.

Yes I know that using a LOG pushes all values on the waveform down in comparison to Rec.709 but I really don't want my LOG footage to be underexposed because, as you know, this comes together with a lot of unwanted noise in the shadows. And from the test we made I can say the footage was so underexposed that we could not save it in Resolve. Thats why I wanted to find out how to expose correctly. Either ETTR or with a gray card. But the gray card did not answered our questions at all, hence I started this topic. So you recomend to use a Rec.709 LUT on the monitor/viewfinder together with a waveform (also with the LUT applied.) and expose only using IRE values of 70% skin and 90% white? And does mean 90% white, when shooting regular Rec.709 (no LOG), that there is still some information left or is it already burning out? I'm not sure if it's possible to show a waveform with a LUT applied to it. I have to try it the next time I have access to the camera. But according to you, I can use the LOG waveform on around 60% IRE for white?

Thank you for your replies. Okay I understand that I prevent clipping in the highlights and in the shadows with this approach. But how do I know if I have consistency in the midtones in different lighting situations for example in the skintones? As far as I know, canon says that the best setting for c.log3 is 800 ISO. That's why we set it like this in camera and on the seconic.

Hey! Some friends and me tried to expose log with an 18% gray card. We used a canon c300 mk2 with the c.log 3 cinema gamut picture profile. Canon gives the following IRE values for c.log3: 18% Gray → 34,3% | 90% White → 56.4% But before we tried to use canons values we tried to replicate this workflow to derive the values: https://www.youtube.com/watch?v=WZb3u220EwU So we set our camera and seconic light meter to 800 ISO and used the spot meter right next to the camera on the 18% Gray chart. We got a value of F 5.68. Our next step was to set the lens to a F-stop of nearly F 5.68. The waveform gave us a value of 26%. This is not only a big difference to 34,3%, the value of canon, the picture was clearly underexposed. :huh: Of course, we asked us what our mistake was. Was it the fault of the video? Is our gray card not standardized? Is our light meter broken? Is a F 5.68 not a F 5.68 on the lens we used, maybe its broken? Is the camera screwing us? Then we stumbled over this article: http://bythom.com/graycards.htm The author, Thom Hogan, tells us that cameras don't see 18% gray. Instead they see 12% gray. This article confused us a lot. We don't know what to think about light metering. :unsure: What is true and what is a myth? What do you think about all this? Are you noticing a mistake we made? How is your workflow for exposing log gamma curves? Do you use a gray card, a light meter, ETTR (expose to the right)? Do you use a Bt.709 LUT on your monitor/viewfinder and expose just with that? And do you understand the 12% gray article and do you think it's true/false? Thank you for your help! :) Levin Liebig

Hello Anthony Liu. There're lots of different gels available. Some of them with a blue-magenta tint. Also it is possible to use more than one gel on a light. Which gels they used exactly, is hard to tell. If you want to go for a specific look take a camera and try different gels and combination of gels. Be aware that some effect gels might look absolutely fine with your eyes but not on the sensor/film material.