Flat frame

[Kevin West]

Sorry to hog the forum but another query.
Please could you photometrists take a peek at my first flat frame.
It looks pretty messy to me. Both B & V filters display the same pattern so I’m guessing there
is a lot of dust on the detector window.
Is it a good idea to try and blow some off?
Thanks for your continuing help.
Kevin

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[Tim Haymes]

Yes! You might be able to blow some of it off, but i would use a DSLR camera sensor cleaning kit to remove the remainder.
-and keep the glass covered up !
Cheers – Tim

[Tim Haymes]

I have done some photometry and i aim to start with a nice clean sensor window. Any other shadows may be from the filters. I don’t clean the filters and if in a filter changer, are protected somewhat.

For sensor window cleaning, I use a Delkin-Devices Digital Duster kit (They can found on e-bay). The “wand tips” are of card-like material to which a few drops of cleaner solution is added (It soaks in). The damp wand is then drawn cross the sensor slowly in one direction. The tip can be cut down to fit the sensor. Then test the camera, or if you have a eyepiece or something under a bright light, its possible to see any dust or hairs. It may be an idea to used the blower, but the danger then is that you blow material back on the window.

If you have a camera serviced in the UK (Starlight Xpress, ATik) then it may be possible to send the camera to them for cleaning. I know Starlight used to do this. Its worth asking.

This link helps to identfy the source of shadows: https://astronomy.tools/calculators/dust_reflection_calculator

• This reply was modified 1 year ago by Tim Haymes.

[Kevin West]

Thanks Tim for the information
Regards
Kevin

[Kevin West]

Thanks Tim,
I couldn’t find them on EBay but camera shops stock them.
Bought a kit and it worked very well.
Kevin

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