Ngc 253

[Jon (Jonathan)]

This is 72 mins of data on NGC 253. I'll try and get some more tomorrow night. EOS 60Da, 10"SCT with f/6.3 flattener/reducer

[Lee]

Good effort - you have captured some rich colour there....

[lazjen (Chris)]

What's the length of each exposure?

[Jon (Jonathan)]

This one is 9 exposures of 8 minutes each. They need to be that long because I was using an Astronomik CLS filter to cut down light pollution. If I was not using the filter then I'd probably go for 5 minute exposures. Having said that, I was happy with how round the stars turned out for 8 min exposures.

[5ash (Philip)]

Hi Jon ,
Have you cropped this picture ? Looks very much like the size and quality i used to get for this object using a Samsung scb 4000 ( 1/2 " sensor ) and my c9.25" at f3.3. Nice picture.
Regards philip

This is the 820x576 picture taken with the humble CCD video samsung, 100x 10.2sec integrations stacked in DSS

[lazjen (Chris)]

Originally Posted by Jon

This one is 9 exposures of 8 minutes each. They need to be that long because I was using an Astronomik CLS filter to cut down light pollution. If I was not using the filter then I'd probably go for 5 minute exposures. Having said that, I was happy with how round the stars turned out for 8 min exposures.

Yes, I did notice the nice round stars. You've given me something to aim for - I've got a LPS filter on the way, so I'm hoping to be able to go for longer exposures without complete washout from LP.

What ISO were you shooting at? How many darks did you use?

[Jon (Jonathan)]

5ash - yes, it's cropped. Using the focal reducer and the 1.25" filter creates a fair amount of vignetting on the big 22x15mm DSLR chip. I can usually get rid of most/all with flats, but with this amount of vignetting getting the flat exposure right can be fiddly. Easier to crop an image that has a single central object of interest.

Chris - I used around 30 darks, 20 flats, 20 dark flats. ISO 800, which is the "sweet spot" for S/N for this camera.