Bob's AstroGallery

M 3

by on Aug.16, 2011, under Messier Objects

After many weeks of bad weather and no clear skies, last night finally showed proof that there is actually something behind those clouds.
Unfortunately it was short-lived, after setting up my gear, I was able to take only 3 frames of M3; the clouds were already coming back, fast.
But it was worth it, I could finally test the Intes Mikro 0.6x focal reducer.
This reducer does not correct for anything, unlike most SCT focal reducers, and I had hoped it would produce coma-free pictures.
As you can see in the picture, it isn’t nearly coma free – and this was taken with a small CCD camera!
Vignetting is also quite apparent. I didn’t make any flats though, those would take care of this problem perfectly.

This really is unfortunate, because it means I still have to wait for Celestron to produce their dedicated C9.25 EdgeHD focal reducers, which will undoubtedly be very costly.

Wolfgang Ransburg, from Teleskop-Service, was kind enough to sell me a discount Intes Mikro focal reducer, with the option to return it in case it wouldn’t live up to our expectations (he thought, or hoped, that this reducer would fit the EdgeHD series).
So, from this short test alone, I think I can safely conclude that this focal reducer is not compatible with the C9.25 EdgeHD.
If I would use my Canon DSLR, with its much larger CMOS chip, the coma will be much worse.

Type: Globular Cluster
A.k.a.: NGC 5272
Constellation: Canes Venatici
Distance From Earth: 33,900 light years

Camera: Atik 314L color
Exposure: 3x240s light frames, 0 dark frames, 0 flats.
Filters: Hutech IDAS LPS-P2
Telescope: C9.25 EdgeHD
Focal reducer: Intes Mikro 0.6x


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