Grey Blobs When Using Reducer/Flattener - Dust?

[Sabalias]

Hi All,

I hope someone can help; I've recently bought a QHY 8L second hand from another SGLer (thanks Nish) and last night was my first try. I managed to get it working and captured some trial images. The problem I found was that there were (what appears to be) dust spots all over the image so I did some testing today by taking some pseudo-flats.

Camera on it's own - no blobs

Camera with Reducer/Flattener - blobs

So I took everything apart and gave the R/F a careful clean and tried again. I got exactly the same results:

Can anyone advise me what these are please? I can't see any obvious dust one the R/F anymore and the camera looks clean too. Are they reflections?

Many thanks,

Stu

[Davey-T]

Just the normal dust bunnies, flats should take care of them, might need a microscope to actually see them.

Dave

[Sabalias]

3 hours ago, Davey-T said:

Just the normal dust bunnies, flats should take care of them, might need a microscope to actually see them.

Dave

Thanks Dave. I thought it might be but I'm shocked at the number across the frame given that I don't think I saw any when I used my DSLR.

Stu

[Chefgage]

19 hours ago, Sabalias said:

Thanks Dave. I thought it might be but I'm shocked at the number across the frame given that I don't think I saw any when I used my DSLR.

Stu

I have the exact same issue. Never saw them with my 72ed refractor, ovl flattener, DSLR and filter combination. Now I use a astro cooled camera with a UV/IR cut filter and the same ovl and 72ed refractor and now get the big blobs over my subs. 

So I assume it's dust on either the new camera or filter or both. But flats take care of it so they don't appear on my final image.