Videokarma.org TV - Video - Vintage Television & Radio Forums

Videokarma.org TV - Video - Vintage Television & Radio Forums (http://www.videokarma.org/index.php)
-   Television Broadcast Gear (http://www.videokarma.org/forumdisplay.php?f=174)
-   -   Sony HVC-2400 low-light focusing (http://www.videokarma.org/showthread.php?t=268311)

Macdude 01-05-2017 09:15 AM

Sony HVC-2400 low-light focusing
 
I realize this is a home Trinicon camera. I wasn't sure where else to post.

I have an HVC-2400 and a HVC-2200 camera. Both are manual focus. These are the style that connect with Sony K connectors to portable Betamax units. I've noticed that if I zoom in tight, focus, then zoom out, the picture will go soft. This happens in low light. I understand the shallow depth of field at that iris position, but if it's sharp zoomed in, why does it go fuzzy when zooming out? When this happens, I can't improve the focus at all after zooming out, it remains soft, so I don't feel as though something is odd with the lens. I never seem to have this issue shooting outdoors in daylight.

I believe it uses a Canon parfocal lens, but I can't verify that. This makes using the power zoom quite difficult. Both cameras act this way, hard to keep focus in low light. Is there any explanation for this?

https://s24.postimg.org/6tfbpupz9/so...153edd8a03.jpg

https://s29.postimg.org/nydrnrgmf/31...5369f101_b.jpg

Dave A 01-05-2017 01:15 PM

It could be what is known as back focus where the tube in this case has moved somehow in its mount away from the focus point at the back of the lens. If the lens is removable you could try another lens otherwise you would have to crack the case open and see if the tube is able to slide in its yoke. Usually a screw clamp somewhere to hold it in place. Lots of voltage around the tube so do so carefully.


All times are GMT -5. The time now is 01:00 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
ęCopyright 2012 VideoKarma.org, All rights reserved.