Can someone explain "knee" & "slope"

[Tom Roper]

Originally Posted by Bob Grant

Did you manage to find the directory page to those articles?
I'm left taking stabs in the dark trying to find an index of them on that Sony site.

Yes, no Crisping in the EX1 that I can find.

Yes. Piotr started a new thread that links to the 9 Sony Shooting Tips.

http://dvinfo.net/conf/showthread.php?t=123870

One of the lessons is how to use the crispening feature. It's quite like the Canon XH-A1/G1 CORING setting.

[Paul Kellett]

Had a play around today with knee and slope settings today, very interesting.
I put some PP's with knee alterations on Vimeo if anyone's interested in having a look.

www.vimeo.com/paulkellett

Paul.

[Ted OMalley]

Tom,

Amazing post, great info - time to play and practice!

Paul, thanks for the video samples - that was great

[Paul Kellett]

No problem. I had some time on my hands today so thought i'd do something useful.
I hope it helps someone out.
I can see that PP helping me a lot at weddings, you know, outside,sunlight, white dresses everywhere.
Hopefully it'll be ok in darker scenes, i believe that the cine's aren't so good in low light, as is detail on, ie creating noise.

Paul.

[Noah Yuan-Vogel]

paul, in the video a bunch of the profiles you say have no 100% zebras definitely still look like they are still blown out in spots. I think those profiles just have the knee set in such a way that it is throwing off the white level. this doesnt prevent blowing out, it just makes blown out areas greyish which looks a bit unnatural as does the gamma curve in the highlights. if this is the case, you also arent using all 8bits you have available, which isnt a ton to begin with, so id recommend using profiles that use all 8bits. do those picture profiles show 100% zebras even when you point a bright light right at the camera and everything is definitely blown out? if your white level is like 95% then your 100% zebras will never show no matter what you shoot.

edit: sorry just read this thread a bit more and it sounds like this was covered to some extent, sorry if it was redundant at all.

[Leonard Levy]

Be conservative in setting your knees parameters. An aggressive knee that looks great on one shot and saves your highlights can totally screw up another. Most techs like to paint their knee on a per shot basis and if they set something for general use it is not that intense.

The auto knee on this camera is the worst circuit in the Ex-1 because it will change the picture as you pan past something bright. Unacceptable in my book. Worst auto knee I've seen since the BVP550 years ago which was even worse. usually they are pretty seamless.

I can't remember what I set mine at but I think it was around point of 93 with a slope of 50. If its different I'll post that. it works pretty well as a general setting.

Lenny Levy

[Piotr Wozniacki]

Lenny is right - only modify you knee's point and slope on the "per scene" basis, or you will ruin other scenes.

Also, switching the auto knee off (with other parameters at default values, or close) is a good idea. This alone helped me tremendously in avoiding the "abrupt highlights clipping" phenomenon (well, in most cases).

[Dave Bingham]

I occasionally shoot in an outdoor amphitheater that has a huge awning diffusing the sun. The main speaker in on the stage with a hot forest background with a lake. The talks are about 90 minutes long. I have to shot a whole week of them in a few weeks and I have yet to get satisfactory video using PP setting alone. I have to color correct to get some contrast in the speakers face or anything on stage. I hate having to color correct since it takes so long to render and compress for the web. Any PP and knee settings that you pro's have that will work in a situation like this?

Thanks.

[Dave Bingham]

I watched Paul's Vimeo video and tried his settings. Much better image. Has a lot of punch and is not flat looking at all. Now over saturated to the point of being almost cartoonish. Will continue tweaking tomorrow.