View Full Version : focus issue with the V1


Sandy Tedford
April 24th, 2009, 07:05 PM
Hello all. wondered if you could help....

I am experiencing some focus issues with the V1 for some reason. I am filming in a studio with a mixture of soft and hard lighting depending on what i am shooting. As a casting director I need to film people acting.

we have the camera set on 25p and the sharpness setting is set up to 12 but for some reason the image appears a little soft on wide shots. this tends to improve when you zoom in for a close up but on occasion the V1 struggles to hold focus with movement even when close.

it also looks a little like the top of the picture is more out of focus that the bottom when shooting wide.

does anyone have any advice or ideas why???

your help is as ALWAYS much appreciated.......

Sandy


.........getting there slowly........

Stephan Stryhanyn
April 25th, 2009, 01:42 AM
Depending on how much they cost, zoom lenses will give a softer image at widest zoom and full open iris. I always zoom in a little.

Watch & read this from the experts, if you're patient enough for this highly technical stuff:
Lenses & MTF Curves (http://www.zeiss.com/c12567a8003b58b9/Contents-Frame/d9a30a166f326924c125751a004ab770) (2 parts, the 2nd one the best - thanks to Adam Wilt for the heads up)
Demystifying Digital Camera Specifications (http://media.panavision.com/ScreeningRoom/Screening_Room/Demystifying_Part1.html)

As for setting in-cam sharpening to 12, mind the aliasing artifacts.

Tom Hardwick
April 25th, 2009, 05:07 AM
it also looks a little like the top of the picture is more out of focus that the bottom when shooting wide.
does anyone have any advice or ideas why???

You're sure the camera hasn't been dropped or banged Sandy? It sounds to me like you need to shoot some test footage, as it may well be that the camera needs to go back under Sony's Silver Seal guarantee.

Set up the camera on a good solid tripod perpendicular to a brick wall, Steadyshot on or off, such that on full wide the entire screen is covered in bricks. Use the NDs and up the shutter speed such that you're using f/1.6 and using full wide, shoot the wall. Tell the mics what you're doing.

Now go to full tele, change the shutter speed to allow f/2.8 and again, shoot some more and tell the mics. More tests with 50i and 25p.

This will show you if you really do have a 20x zoom, but more importantly calm or frighten you as regards the softness you're seeing. View the footage on the best TV or monitor you've got, and have 'display' turned on to clarify things.

Come back and tell us what you see.

tom.

Sandy Tedford
April 27th, 2009, 03:30 PM
Hey,

thanks so much for the reply. Had to shoot more footage today and 25p seemed better. Ill look at both your suggestions and get back to you.

Ill try to put up some test footage so you can see what im talking about but ill have to do it on a secure site as they are casting tapes and i cant just put them on the web.

I really hope there is not a problem with the camera but i have a feeling that there may be an issue.

thanks again

sandy