Fogging

[Paul Dunning]

Hi Val,

Is there any chance your dark band could be caused by bellows shadow? From your description it sounds like something I've experienced when using a lot of rise/fall causing the bellows to intersect the image circle. Then again, if it's dark in the negative then that couldn't be the case.

Paul.

[gary mulder]

I have noticed that some people when replacing the slide they insert one corner first. In an attempt to make it more smooth. But this can cause light leak.

[Valerio Trigari]

Hi Val,

Is there any chance your dark band could be caused by bellows shadow? From your description it sounds like something I've experienced when using a lot of rise/fall causing the bellows to intersect the image circle. Then again, if it's dark in the negative then that couldn't be the case.

Paul.

I thought that as well, but I had the issue even with no movements whatsoever. Also, as you pointed out, the band is dark in the negative, so it can't be due to vignetting.

I have noticed that some people when replacing the slide they insert one corner first. In an attempt to make it more smooth. But this can cause light leak.

I insert both corners of the slide at the same time.

Cheers,

Valerio

[Valerio Trigari]

Here's an example of my negatives being fogged (the image has not been edited or anything). As you can see there's a nasty white band at the bottom... What would you think is the cause of it?

[Susie Frith]

Hi Nick.

I haven't been able to view your fogged pics, but is there any possibility of the sheets of film bowing and touching one another while they are in the developing tank and therefore not coming into contact with the developer?

Just a thought,

Susie

[gary mulder]

it's most likely that your dark slide is leaking. The only other thing I can think of, is that with a linhof back, some dark slide's do not go in easy all the way. They halt just 2-3 mm short. The slot between the linhof back end the dark slide will not be engaged properly. I have a linhof so do not ask why I know.

[Paul Mitchell]

I concur with Gary, it's too localised to be a developing issue and shows all the classic signs of a darkslide leak

Paul

[Susie Frith]

Hi Gary and Paul,

My reply was to Nick's original question on this post - fogging in the centre of the image. Unfortunately, the image is showing as no longer available to view.

I agree that Valerio's fog is due to the darkslide not going all the way in.

Susie

[Valerio Trigari]

Thank you all for sharing your point of view on my fogging issue. So it is as I suspected, a leak from the dark slide. Though I didn't realise the fogging could be due to the dark slide not going all the way in. I will check if that's the case, though some of my negatives don't show any fogging at all, so it could be more me not being careful enough when I insert the dark slide in the holder.

[Valerio Trigari]

I finally found the responsible for the fogging *roll drums and draw the curtains*: myself! I discovered that when inserting the film holder into the back of my Linhof, I did not insert it right to the bottom... I should have noticed that nice "click" sound when the holder is in its proper place.

A quick experiment confirmed my hypothesis:

1. I removed the camera back from the camera;
2. put the film holder in the wrong position;
3. removed the dark slide;
4. pointed the whole thing towards a bright light, with the dark slide used a shield to prevent the light to hit the film directly (I had a sheet of film for these purposes).

Sure enough I could see a nice band of light right where it appeared on my negatives. After placing the film holder in the correct position and repeating the experiment, I could not see any light whatsoever hitting the film. Just to be sure I conducted the test on each double side of my six film holder. Luckily all of them are perfectly light tight.

All I can say is live and learn!

Val

[Valerio Trigari]

As expected, inserting the film holder all the way into the back of the camera solved the problem! I shot 12 sheets last weekend and none of them has the slightest sign of fogging.