HELP! Is this moisture stuck in the focusing screen? ...or worse?

[antonio_di_benedetto]

<p>I went to out in the snow last night to photograph with a Hasselblad 500c/m. The camera got very wet, but I was happy that the lens element stayed bone dry. Then I realized that there was a weird circle in the focusing screen while I was shooting. It was still there after I was done and had gone home. I left the camera out on my coffee table to warm up and dry, but when I woke up I saw that the circle was still there. I thought the focusing screen had cracked from pressure or something, but I could not feel anything amiss when I ran my finger across it.</p>

<p>Now I am wondering if it is moisture trapped between the plates of the screen. Last night it was a full circle, and this morning it was a a doughnut shape (hole in the center of circle).</p>

<p>I am still nervous about it, so I am seeking anybody who knows better. Here is a picture of it from my cell phone:<br>

<img src="http://i.imgur.com/YCcKBl.jpg" alt="" width="480" height="640" /><br>

http://imgur.com/YCcKB.jpg (full resolution)</p>

<p>Anybody have any ideas?</p>

<p>Thank you.</p>

[john_a5]

<p>First, take out the focusing screen, very easy to do if you don't know how, just take off hood and pop out the ground glass--then dry it.</p>

[scott_murphy_photography]

<p>Take the WLF off and remove the screen and place it in a warm place, like a window sill with sun shining on it and let it dry out. I am pretty confident that will do the trick.</p>

[antonio_di_benedetto]

<p>Thank you. I will do that as soon as I get the chance.</p>

<p>So it definitely is just moisture, correct? Nothing seriously damaging?</p>

[john_a5]

<p>Antonio, if your lenses are all right, then it probably isn't anything to worry about. Let the whole things just air out in a warm, dry place. There could be water on the mirror, but you will see that when you take off the ground glass. Even if a mark remains, it should neither affect your images or the function of the camera--I have plenty of marks on various camera's ground glass viewfinders, it is just one of those things that can happen with use.</p>

[john_layton]

<p>...but don't give up on using your Hasselblad in the snow! Do you have a prism finder? If not, maybe at least buy a cheap (Kiev) prism - mount this on the camera, and place the whole deal up into the bottom of a Ziplock bag. Next, stretch part of this bag tight over the lens as you mount a filter - maybe letting the bag loosen just slightly as the filter gets mounted. Remove the filter and then remove the circle of plastic which the filter had nearly cut through, then re-mount the filter, carefully aligning the cut out hole over the lens so that it becomes trapped under the filters rim. If the hole is too big for this - use an elastic band to affix the hole surrounding the filter. Next - assuming you have an eyecup for the prism finder...do the same thing with this as you did with the lens filter - and presto...you have a great weather resistant arrangement - which, by leaving the bottom of the bag open, allows you to grasp all of the controls comfortably. You can tripod mount this also. Works like a charm! </p>

<p>In the meantime, good luck getting the water out from between the upper and lower layers of the screen. You may be able to do this with heat...but be careful. You don't want to warp anything which might throw off accurate focus! Perhaps just leave it in the sunlight for awhile. You might also be able to take the screen apart - but be very careful of delicate inner surfaces - and to see that everything gets put together properly. I've never had a Hasselblad screen apart before - so maybe someone who has can chime in on this.</p>

[jrsmith]

<p>Never try to take a Hasselblad focusing screen apart. Especially if it is an Acute Matt - that could be a very expensive mistake. Never use solvents to clean them either. The upper surface of the screen can be cleaned in just the same way as a lens, with equal care. The underside is very delicate, and should only ever be lightly brushed with a camel hair brush or similar to remove dust.<br>

John</p>

[q.g._de_bakker]

<p>I second John's advice.</p>

<p>Will add that using fluids to clean the screens is also rather dangerous. You do not need a soaking in rain to produce what Antonio is trying to get rid of.<br>

And it takes only a single, small drop seeping in between the two bits that make up the screen sandwich to replicate this. So watch out!</p>

[james_brand]

<p>I took apart an Accutemat screen once. It was not a good idea. The glass screen must be only 1/32 of an inch thick. How I managed to get it all back together without breaking it is beyond me. I would not be eager to try it again!</p>