In cold weather, my mirror doesn't flap up!

[sina_khorsand]

<p>Hey guys- <br>

I'm having a bit of a problem. In cold weather (like right now its 50 degrees F), my RB67 Pro S doesn't like to fire properly. I notice that the shutter closes, but stays closed because the mirror doesnt flip up to activate the shutter. I usually have to cock and fire the damn thing multiple times before it actually manages to fire. Whats odd is, that even in really cold weather, if I take the back off it fires perfectly. Only when the back is on in cold weather does the mirror have trouble flipping up and activating the shutter. So, you guys know of any solutions? What part of the camera would I lubricate?<br>

Also while I'm at it:<br>

I'll be going to Lake Tahoe, Ca this weekend. Temperatures will reach as low as 15 degrees F. I'm planning on doing star trails, leaving the shutter open for at least 4 hours. Should I be worried about my shutter sticking/freezing open, or my mirror freezing up? And what about condensation forming on the lens, what is a good way to prevent that?</p>

<p>Thanks!!<br>

-sina<br>

<a href="http://www.flickr.com/photos/57709377@N08/">http://www.flickr.com/photos/57709377@N08/</a></p>

[frank_skomial]

<p>For Pentax 6x7 the solution was to use an external battery cable. (optional Petax item).</p>

<p>One end of it is in the camera in place of the battery, and the other end of it holds the battery, and his end is supposed to be placed close to your body heat, inside your coat, etc.... works well.</p>

<p>Perhaps the camera has sufficient lubrication ?<br /> Adding more of lubricant that could possibly get harder in low temperatures, could make it worse.<br /> Perhaps your problem is not with the camera lubrication, but with the battery voltage drop?</p>

<p>Come to think of it...does you camera use a battery ?</p>

[sina_khorsand]

<p>Battery? The RB is completely mechanical. It may be the lubrication in the component that actuates the mirror release. </p>

[chris_waller]

<p>The lubricant has hardened with age. I would suggest a CLA with a professional camera technician. Trying to do it yourself might cause more problems.</p>

[dan_daniel2]

<p>Cold weather presents problems for cameras and lubricants. Sometimes people would get cameras overhauled and special lubes installed if they were going into freezing places. Best to find an experienced repairman.</p>

<p>Astronomy and astro-photography people have a variety of tricks to make standing in one place in sub-freezing temperatures possible. This includes ways to wrap and heat equipment if needed. Maybe some of their techniques would help you.</p>

[wogears]

<p>I have a PDF of the repair manual, if you need it.</p>

[q.g._de_bakker]

<i>"Only when the back is on in cold weather does the mirror have trouble flipping up and activating the shutter."</i><br><br>So it would work in cold weather without back on? If so, the back would be suspect either as sole or co-cause.

[bobbuck19]

<p>I've used disposable handwarmers rubberbanded to the lens barrel to keep dew and frost off the lens for star trails, maybe a couple more around the body and wrapped with something would keep the mirror from freezing open. Doesn't the RB have leaf shutters in the lens? if so the handwarmers might be a temporary fix until cla'ed. I have a 65 for a 330 that gives me trouble in cold weather, it can be annoying.</p>

[sina_khorsand]

<p>PDF would be great! The problem occurs with both backs so I dont think its the back. </p>

[paul ron]

<p>oooooo wait, maybe the 2 pin's mechanisms are the problem...<br>

CLA will take care of your problem... $75 and it's a new camera</p>

<p><br />paul.</p>