View Full Version : Open the Iris or add gain? Which?


Mark McCarthy
March 26th, 2003, 04:18 AM
Hello all!

Just playing with my XL1S last night in dark conditions. I have a corporate shoot coming up and and much of it will be filmed indoors.

What do you think would provide the better picture?

- Fully opening up the iris or adding gain?

I know the camera's sweet spot is around f 5.6, and opening it below F4 isn't ideal, but isn't this better than adding gain?

Your help would be most welcome.

p.s. I freelanced yesterday with a DSR 500 and full kit. What a camera eh? ...Still like my canon though!!

Don Palomaki
March 26th, 2003, 04:39 AM
Add light to the set if you can.

If you can't add light it is a trade-off between some image noise increase with incresisng gain, and lens performnce falloff as the aperture is opened wide, including changes in depth of field.

I think you need to run your own tests to see which works best for your subject matter.

Tom Hardwick
March 27th, 2003, 12:36 PM
Without a doubt Mark use maximum aperture first, before you add any gain-up. Don does raise a point though that if a certain DOF is required then max aperture might be a no-call, but if it's quality you're after then it's max aperture all the way.

Modern lenses are just so good wide open. They vignette the image slightly, but the 1.5 stops down in the corners will go un-noticed by nearly everyone. The grain added by gain-up will be there for all to see however, and if you're going the DVD route then it's even more important that you avoid grain as MPEG2 will try its hardest to capture it in all its detail.

As to the sweet spot - you're much more likely to find it's f4 rather than f5.6, especially with tiny 1/3" chips. At wide-angle settings the diffraction losses start to come into play at apertures smaller than f4, and as I've said before - be much more afraid of f11 than you are of f1.6

tom.

Mark McCarthy
March 27th, 2003, 03:21 PM
Thanks for taking the time out to offer some advice Tom.

I didn't know it was best to shoot at F4 at all times, I've been doing my best to stay around the f7 mark, thinking it performed best here.
I am only a newcomer to the camera, and appreciate the advice.

I am getting to grips with it and am producing some some good stuff.
Cheers Tom.
Mark

Mark McCarthy
March 28th, 2003, 04:01 AM
I see you're from Billericay! Know it well, anyway...
any advice for a top light for the XL1s? What do you use?
many thanks
Mark

Don Palomaki
March 28th, 2003, 05:35 AM
I use a Cool Lux Mini Cool with a 20 watt lamp and the wide angle diffuser.

However, the best will light will depend on what you are shooting.