Tim Dashwood |
October 10th, 2005 07:49 PM |
I feel inclined to defend my earlier post and the responses it has received.
Quote:
Originally Posted by Steve Mullen
Quote:
Originally Posted by Tim Dashwood
Steve suggested it is caused by insufficient light, and that you will "need at least a reading of F2 - AVERAGE."
|
Actually, I later raised this to F4 to compensate for the possibility that you might have a statistically "non-normal (non bell shaped curve) where a few bright lights caused you to set the exposure higher than it should be for the larger dark areas. This was also a simply way to keep the F-stop at the setting where the lens offers the most rez as measured by you and/or Berry. (There's nothing wrong with F2 or F2.8 in "normal" situations, but you are scarificing resolution.)
Now my logic may be wrong, but the results I get speak for themselves. No SSE and max rez.
I'll admit I did not think about those who are not into reality shooting. And, at that time most of the discussions were about shooting reality -- weddings and docs.
You feel my "rule" would prevent creative -- dark mood -- shots. I don't think is true.
|
Steve. I was directly responding to your post in another thread that has propogated itself as a "rule-of-thumb" since then:
Quote:
Originally Posted by Steve Mullen (on 09-29-2005 from another thread)
"As I've already said, there must be enough light to get at least an F2 reading. But, that reading is an AVERAGE reading from the camera system.
Imagine a white product that fills about half the frame. Behind it, a deep purple cloth. The reading is F2.8. All is fine -- right?
Maybe not. If the white reading is F4 -- the purple must have a reading of F1.4. Which means it doesn't have enough light on it.
Which leads to the obvious solution. Simply zoom into dark areas (not the full black areas) and check the F-stop. If it is F2 -- or better -- then there should be enough light to avoid any split-screen effect.
"
|
I was trying to make the point that the SSE in my FW1.14 camera doesn't just have a max threshold where it goes away. It has a minimum and a maximum response threshold based on IRE. IRE is the only repeatable measurement that can be used objectively when measuring the SSE. The relative exposure you used will differ depending on what custom gamma curve, gain level, shutter speed and how each operator chooses to rate the camera/curve's ASA - auto exposure included.
Quote:
Originally Posted by Steve Mullen
What they want is to CREATE the LOOK of dark. Which brings up the old confusion of film students -- sometimes they hear someone use "F-stop" to mean an amount of light (as used by a director), other times "F-stop" means a setting on a camera. I think you have confused the two meanings. I can dig out a quote from one of my Cinematography books that explains this much more clearly than I can.
|
I don't want this to become a battle of the brains because I think that the work both of us have done can help the community, but I don't think I confused anything. Your "purple cloth" analogy seemed pretty clear.
In my defense, I was trained by "old school" DPs, I generally shoot using a "base stop" based on how I rate a particular film stock based on push/pull/ENR/BB processing, grain and the response curve (Vision stocks pick up more detail in shadows, etc.) The same applies for video - and I have been giving different exposure ratings to my different curves. BTW, I also know the difference between an ƒ stop and a T stop.
Quote:
Originally Posted by Steve Mullen
What I "sense" you are doing by dropping MB is forcing the darker areas to become fully black. Since at first, it seemed it was the dark, but NOT black, areas that got SSE this idea works. Until you realize that you can get SSE on a white wall if the lens reads OPEN. Clearly, lowering MB by a 3, will not bring that white wall into black.
|
Like I said in my post, my v.1.14 camera doesn't show SSE on white walls. My tests were based on one camera only. The Master Black solution only applies to my camera (and possibly other v1.14 cameras.) I'm waiting for others to report back if it helps their situation. I have also found that the MB NORMAL wasn't anywhere near 0 black anyway, so crushing them slightly doesn't actually have any adverse effects, especially when using a wide dynamic range curve.
Quote:
Originally Posted by Steve Mullen
2) We both have stumbled upon "solutions" but they are not universal. In which case, we have tried but failed.
|
agreed.
Quote:
Originally Posted by Steve Mullen
3) Ideally, JVC will allow their engineers to publish a White Paper on SSE and HOW TO MINIMIZE IT. As long as the internet is buzzing with folks like us trying to solve THEIR problem without a deep understanding of the nature of the problem -- SSE will stay a thorn in their side!
|
I hope it doesn't come to that. Ideally this problem will be gone by the end of the month, and then it won't be a thorn in anyone's side.
Tim
|