I'd never thought of a small dew heater strap. Must buy one and try. I feel pretty confident the bag+argon takes care of the internal stuff. Just make sure you don't mislay the sealing ring for the nose section when reinstalling.
The other suggestion here re sticky stuff to catch the dust also sounds interesting.
I use acetone to clean the CCD followed by a microfibre cloth after it's dry.
PS, I'm using the QHY8Pro on the C8 front with a hyperstar for LMC stuff at the moment, so I imagine spacing there would be even more critical, although the IR external filter side is enclosed quite well. Still fogged up. Dew heater sounds the trick.
Peter, you need to make sure that the surface of the CCD is clean. Use Acetone to revove any residue on the CCD. Even when you think its clean, its not. Acetone will remove this, and dont be afraid to use a large quantity as well. Just make sure its dry before re assembly. There is also desicant strips that stick on inside the camera or anywhere for that matter, and absorb a very large amount of moisture.
If any one opens up a camera, regardless of model, and either doesnt have time or availability of desicants, bags, etc, then i suggest standing in front of a heater/hair dryer etc, while re sealing the camera. This way only hot dry air is blowing over the chamber, and when sealed, the air inside is dry.
Theo
Theo,
Thanks for the advice. When I last opened it up I used iso-propyl alcohol to clean the CCD. When I put it back together I ran it for a few hours without any issues however it seems to still get some moisture in from time to time.
Can you post a link to the dessicant strips you refer to?
Thanks Martin. I couldn't see any mention of them on Theo's site.
Have you used them? Where do you place them and how often do they need to be replaced?
Peter
Yeh i have been asking for listings of accessories on the websites but it looks like it ain't going to happen.
Although some sellers do list accessories
This is the reason that i am making and doing my own stuff.
The deccicant strip has to sit at the bottom of the ccd chamber.
In my QHY9 it sat at the top and caused my ccd to freeze up.
I turned the chamber around and fitted also very thin double sided tape on the remaining three sides of the chamber (for catching dust particles).
I have not replaced mine since i bought the camera (2 years ago).
I've been busy tonight. The dessicant strips arrived today however I was under the impression they were self adhesive but they don't seem to be.
So rather than have something floating around in the camera I've decided to try just the Argon charge first and if that doesn't work then go for the dessicant.
I've filled and emptied the bag three times and will now leave it to soak for a few days before re-assembling the camera.
I've got 60 litres of Argon to play with so should be able to give this a few tries.
Peter
A snazzy setup. I may have to resort to something like this when the QSI argon eventually leaks out.
By the way a small suggestion. I would try double bagging to stop argon and air mixing.
Hi Theo,
I'm interested in the new Thicker Front filter for the QHY8, trying to reduce reflections and icing.
Please let me know the price etc.
Many thanks
Jim
Quote:
Originally Posted by Gama
Hi Adam, The QHY-8 is an obsolete camera now, and is only being sold until old stock is gone.
The replacement is the QHY-8L, and although its a single TEC cooled camera, it still does a very good job cooling. But best of all, its controlable.
All the new QHY cameras have a new thicker front glass filter. This was was two reasons.
1, it helped the reflection issues by the extra AR coating.
2, made thicker so as to help prevent condensation appearing on the outside. Because of the extra glass mass, the condensation was slowed down.
Although its near impossible to prevent condensation on humid nights, regardless of manufacturer, every little bit helps.
These new thicker front filters are available for the older QHY-8, or any camera with a M42 thread. It comes with the Tip Tilt adapter, so you can also align the CCD to the focal plane. Heres the link to it.
If you wish to learn more about it, maybe a personal message, as its getting close to hitting the "TOS"...
