Cambo Actus-DB light leak?

[Boinger]

Hello,

I have been testing my cambo actus db with my H6d-100c / Rodenstock HR 40.

This is my first foray into view cameras or tech cams. Is it normal to have light leaks on long exposures in daylight?

It seems to me the light is entering from near the lens mount bellows.

Short exposures I don't see anything but if I do anything longer I can see a light leak.

Is this something I will have to work around and exists in view cameras? Or is there something wrong with the bellows mount in front?

 

[vjbelle]

The bellows themselves are not as light tight as a stand alone camera. However they are light tight for 'reasonable' long exposures in daylight. I have had one of my bellows replaced due to light leakage under normal exposures. An easy way to check for light leakage is to remove the back or lens and shine a light into the bellows and check for visual light exit points. This is easier in a darkened room using a very bright flashlight or light source. I was easily able to identify light leakage with the bellows that had to be replaced. Expecting the bellows to be perfectly light tight in direct sunlight for a 10 minute exposure is probably expecting too much and under those circumstances I usually add some sort of additional light stoppage around the bellows.

Victor

Edit: You can also check for light leakage by capping the lens and taking a 30-60 second exposure while shinning a light source around various areas of the bellows. If there is a leak it will show up in the file. Otherwise you may notice a faint lightening of black here and there which is to be expected.

 

[Boinger]

I see, I did try the flashlight trick. It seems to be on the lens mount side of things. Where the bellows meet the lens (magnetic on the actus)

I guess I will just put a dark cloth over if I want to do really long exposures.

 

[Hausen]

It was normal for me when I had my Actus. I am a long exposure guy and I carried some blackout cloth and some bull clips. Not that styly a look but it worked.

 

[Boinger]

I emailed Steve Hendrix,

And he pointed out that there is a bolt that is supposed to sit in a hole at 12 o'clock.

I wasn't doing that so the magnetic bellows weren't quite flush with the mount magnet.

I made the correction and now it seems much more light tight.

Flashlight test didn't result in much I will try some more in direct sunlight later.

 

[Hausen]

That certainly makes a difference but my normal working shutter speed was 2m+ and if it was daytime I got light leaks anyway.

I emailed Steve Hendrix,

And he pointed out that there is a bolt that is supposed to sit in a hole at 12 o'clock.

I wasn't doing that so the magnetic bellows weren't quite flush with the mount magnet.

I made the correction and now it seems much more light tight.

Flashlight test didn't result in much I will try some more in direct sunlight later.

 

[Boinger]

That certainly makes a difference but my normal working shutter speed was 2m+ and if it was daytime I got light leaks anyway.

Oh good to know. I will buy some blackout cloth or something to assist. Honestly its hard enough to see the LCD in daylight.