Gain Z1
by Dave Evans
on
Sep 25, 2008 at 7:41:17 am
Hi Guys
How much gain is acceptable with the Z1? I realise this is a loaded question and I know gain = grain but we have a shoot in a Cathederal that is a little compromised for light & we are not allowed to alter things. The cameras & operators arrive tomorrow so I will have a chance to see some test clips, just wondering if anyone has used their Z1's in similar situations & used a wee bit of gain, was it acceptable? or a real no no.
Re: Gain Z1 by Michael Slowe on Sep 25, 2008 at 10:34:16 am
I found no problem whatsoever with gain up to 18db with either the Z1 or the new EX1. I was amazed at what little effect this much gain had on picture quality and you should manage very well if you want to test at this level.
Re: Gain Z1 by Ryan Mast on Sep 25, 2008 at 1:48:30 pm
I disagree. You'll get far better final image quality by leaving the gain entirely off and boosting the exposure in post. If your deliverables are going to be entirely SD, gain isn't an issue, but adding gain in-camera accentuates the sensor noise, wreaking havoc with the HDV codec. You'll definitely use color resolution, and quite likely you'll see some noticeable macroblocking if you have a substantial amount of motion in your image.
YMMV. If you have the ability to boost the exposure in post, do it that way.
Ryan,
How much work have you done with the Z1? Gain in this camera is not a big issue until you get higher than +12.
Increasing exposure in post increases luma and chroma noise, unless you use curves, even then...blacks tend to be screwy, IMO.
Douglas Spotted Eagle
VASST
Certified Sony Vegas Trainer
Aerial Camera/Instructor
Seriously - what Douglas said is spot on, although I would try to stay at +9 max - which should help a TON. Also is there is no movement - or you like the effect you can slow the shutter down to 1/30th - for establishing shots of the ceiling, or windows, cutaways of archatectual elements that could be the way to go.
Thanks,
Harry
Forum Cowmunity Leader: Indie & Doc
Forum Cowmunity Leader: HDV
Re: Gain Z1 by Michael Slowe on Sep 25, 2008 at 3:32:59 pm
Well said Douglas. On a good monitor I can't see any obvious degrading with gain up on the Z1 although it would be better to keep it to 9 as has been stated. I too find increasing the exposure in post is not as good as you loose the black completely and any compensation with plus contrast takes you back where you started.
Re: Gain Z1 by Dave Evans on Sep 26, 2008 at 1:01:45 am
Thanks a bunch guys I feel a whole lot better now.
I must test the 1/25th shutter on some static shots or shots without to much motion to see how it looks.
Re: Gain Z1 by Ryan Mast on Sep 27, 2008 at 1:15:29 am
[Douglas Spotted Eagle]"How much work have you done with the Z1? Gain in this camera is not a big issue until you get higher than +12."
How much work? Not nearly as much as you have, I'm afraid.
This is really good to know, though. I had a couple bad experiences with high gain, so I've just avoided it entirely. How much extra detail in the blacks will it give you to work with?
Re: Gain Z1 by Michael Slowe on Sep 27, 2008 at 12:42:28 pm
Ryan, I have lots of experience with the Z1 and it does handle gain amazingly well, you'll have no problems if the available light forces you to increase gain. Blacks stay pretty good. It's preferable to messing about with shutter speeds.
Re: Gain Z1 by Dave Evans on Sep 28, 2008 at 10:19:15 am
Hi Guys
Thanks again for the info, shoot complete, wont get to have a good look at the footage until Tuesday, we set the cameras up the day before and shot some test stuff which looked very good at 0db. However on the day it was much darker black skies shuting down the available light inside the cathedral, so use of gain was needed.
I used the Z1 for the first time and I must admit it caught me out at first not being able to force the iris to stay fully open on close ups, wide shots were fine but the iris closes to 2.4 through the zoom as you know. Nice camera I need to get more time with it & the V1 as they are very common here.
Re: Gain Z1 by Kevin Shaw on Oct 1, 2008 at 4:18:37 pm
Most modern zoom lenses lose some sensitivity at maximum telephoto, so that's not unique to the Z1.
I regularly run my FX1s up to 18db gain and will often drop the shutter to 1/30 in dark settings, plus boost even further in post if necessary. This yields some noise but is still better than what I could do with my old DV cameras. It also helps to boost the color saturation in-camera using the picture profiles. I typically use +3 or +4 color and know someone who goes all the way to +7.
If you're shopping for an HD camera consider the newer Z7U (or upcoming FX1000) for better low-light response than the Z1.
================
Kevin Shaw
Always Memorable Videos
Re: Gain Z1 by Dave Evans on Oct 3, 2008 at 4:26:15 am
Thanks for the info Kevin
As you can probably tell I do not have much experience on the higher end cameras (relatively speaking), the A1 which seems to have a shorter focul range is our current HDV camera & with lots of light it takes really nice images however after shooting with the Z1 this past weekend its like night & day. So I think we will be saving for a Z5 or if not an FX1000, like you point out they should have good low light performance as well.
Re: Gain Z1 by Michael Slowe on Oct 4, 2008 at 5:38:00 pm
If you're saving for another camera why not go the whole hog and wait for an EX1. The low light performance is awesome, and I went up from a Z1. You don't necessarily have to edit the EX files if you shoot in HDV as I do and then go to tape from the camera via firewire.
