View Full Version : Paucity of image options on FX7...


Tripp Woelfel
December 29th, 2009, 09:58 PM
... or I'm just a pikey.

The setup is that the FX7 is one of three cameras used to broadcast indoor sporting events. The other two are Canon GL2s. We are streaming to the web and sending a feed to a local cable company. I have one major and one minor issue.

The major problem is that the composite output sends highlights at about 110 IRE using an auto iris setting. We can go manual exposure but that crushes the blacks and kills the part of the image I need. Is there a setting where I can raise the gamma (pedestal?) so I end up crushing the highlights (which are nothing but highlight reflections of polished objects)? Been through the manual a couple of times and have found few tweakable items for image adjustment. Is the camera really that dim or am I?
The minor issue is related to the major one. The FX7 is set up for a fairly contrasty image compared to the GL2 and my XH-A1. I'd like to "flatten" the contrast on the Sony a bit. Is there a way to do that? I think that there are some custom settings in the Canon but I'd rather change one Sony than two Canons.

Any help would be appreciated.

Adam Gold
December 30th, 2009, 02:22 AM
Well, you've really got the wrong cam if you want a lot of pro options. But you could try playing with Contrast Enhancer in the main menus and Cinematone Gamma in the picture profiles... but I fear these won't do very much to make you happy.

Tripp Woelfel
December 30th, 2009, 01:41 PM
Well... that's part of the problem. The team bought the camera and I was brought in after the decision was made. I was trying to figure out how I might make some lemonade from the current crop of lemons.

I suspected that there weren't many options but I hoped that there might be some setting on the secret decoder ring that would help.

Adam Gold
December 30th, 2009, 03:00 PM
Yeah, I hear ya. I think we've all been in that situation and know how frustrating that can be.

Other than the tweaks I mentioned, I don't think there are that many other options -- at least none that I know of. Sonys are pretty well-known for being "punchier" right out of the box, for good or ill.

I guess the good news is that if this is going out over the web, no one will notice the difference anyhow. I wonder if, since the others cams are SD and HD resolution isn't necessary, you might try a very light physical fog filter or something else that might lower the contrast a bit?

Tripp Woelfel
January 1st, 2010, 07:41 AM
A TWC engineer told me of a "contrast" filter that will pull up the shadows. Tiffen and somebody else make them and they come in different grade ratings. The Tiffen is just a bit over US$50 so I'll see if I can get the team to pay that tab.

Stephan Stryhanyn
January 26th, 2010, 03:53 PM
Too bad indeed that the FX7 doesn't have Black Stretch / Knee Adjustment settings (like the V1) for those high-contrast situations.

I found the "Tiffen 62mm Ultra Contrast 3 Glass Filter" (62MM ULTRA CONTRAST 3 FILTER - Tiffen.Com (http://www.tiffen.com/displayproduct.html?tablename=filters&itemnum=62UC3)), is that the one you were mentioning? I read the marketing on Tiffen's website and I find it a bit hard to believe that a $50 filter ($46 @ B&H) would flatten contrast without impairing the cam's overall MTF somewhere else. Upgrading my cam's dynamic range up to another class almost for free? When it sounds too good to be true, ...

I'd be most grateful if you could spare a minute giving us some feedback after you've had an opportunity to test this filter. Like for instance:
- Does it really bring shadow details back, or is it just washing out the shadows to make them look brighter (uniform gray).
- Any halo / loss of detail around bright spots?
- Any detrimental impact on picture sharpness and effective camcorder resolution?
- At the end of the day, how much increase in dynamic range (f-stops)

Thanks

Marty Welk
January 26th, 2010, 04:25 PM
This thread is a bit old, but before i slapped a filter on i would try these things.

Adjust the AE shift DOWN this will reduce the Auto iris position some and keep you from going off the top so quickly.
set your AGC (auto gain control) Limiter to 6DB
Use the "Cine" profile.
reduce excessive false sharpening
Turn off contrast enhancer

the thing about cameras like this is they will record from 0-110 (used to be 120 and even 140) giving you a huge range of bit things to work with, in the color correction phase of editing you could take this whole huge range and squeese it into wherever you wanted, by the camera USING this large range that is way over "Broadcast" specs you are not limited to "broadcast" either. If it didnt USE the whole range it would be contrasted down, and/or stuff is just tossed out before you can even color process it. when it comes to digitally compressed stuff then color processing it i prefer having 120% of an image then crushing that into 90% , than to have 90% to begin with, but if you gotta go live with it :-( then you need to do what you can to crush it in the camera.

if your trying to take the Live signal out and feed it to broadcast, then you gotta have blacks that start at 7, and whites that end at 100.
If there was a SETUP in the camera , it would fix the black to the 7, then the iris stuff (and proper lighting) would be adjusted to keep it from going over 100, you do have zebras that you could watch. but no "setup" setting for "broadcast".

You dont want to lose your auto iris, so adjust the auto itself with the AE and/or alternativly turn the spotlight on.
also you probably want that Contrast enhancer stuff turned off, also you might reduce the false sharpening a bit, as sharpening is done by increasing the contrast between pixel items. this means that if there is a bright area, the sharpening matrix will set some of the pixels higher and some lower to define the edge sharper, this will send more pixels higher and lower.

i would bet that filters like these even the best of them, will do more damage than you can do with what little internal camera processing you have available. Along with flatening your lighting a bit, using dulling spray, shooting with clouds or good times outdoors.

In the OPs situation they are feeding a Composite out, (not the greatest way to get a signal out) if they are going to stream or use THAT composite, then just like year1980 analog real time color processing, you just put a "Proc Amp" on the vast complete signal you have there, and crunch it into Broadcast, and send it on its way. Course a meter in there somewhere would be helpfull.