mizar

[neil groves]

This is a pic of Mizar i shot tonight, my very first through my new ed120 with a canon 5D, the exposure is 4.5 mins in 30 sec subs processed in DSS with 5 darks and 10 flats, what would cause the center of the image to be brighter than the outside?....looks like vignetting but shouldn't the flats take care of that?

Neil.

[neil groves]

i took some more shots last night and have the same result......any idea's people?

Neil.

[lensman57]

This is a pic of Mizar i shot tonight, my very first through my new ed120 with a canon 5D, the exposure is 4.5 mins in 30 sec subs processed in DSS with 5 darks and 10 flats, what would cause the center of the image to be brighter than the outside?....looks like vignetting but shouldn't the flats take care of that?

Neil.

Are you using a field flattner ? Even so the FF/FR is only designed to cover up to an APC size sensor just, so with a full frame there is no chance. Try and redo your flats at the end of the imaging session with a flat panel, it may improve but not by much.

A.G

[neil groves]

No i don't have a field flattener yet, what is FF/FR?

Neil.

[neil groves]

I recently bought a Canon T3, just for astrophotography so i will have a go with that when i get a remote release and see what difference a crop sensor makes.

Neil.

[lensman57]

No i don't have a field flattener yet, what is FF/FR?

Neil.

Field Flattner / Focal Reducer, you do need one if you  want to do imaging using a DSLR or a CCD with a Large sensor. Here is a link to one.http://www.firstlightoptics.com/reducersflatteners/skywatcher-85x-reducerflattener-for-ed120.html

A.G

[neil groves]

ugh....more expense, now i have to try and get that past the wife ha ha

cheers Alan

Neil.