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View Full Version here: : Interesting comparison of Refractor vs Reflector


LewisM
11-11-2012, 07:34 PM
and aperture vs no obstruction.

Pretty similar nights. Both of course M42.

This one was through the Northgroup ED127 refractor

http://imageshack.us/f/21/m424nov12.png/

And this through the vixen VC200L

http://imageshack.us/f/84/m42ea.png/

Focal lengths similar (Refractor at 7.5, VC200L at 6.4). Major difference is the TIME - the ED127 is 5 minutes, and the VC200L was 3 minutes. Both have their strenghts and weaknesses.

Personally I tend to like the structure of the reflector and the pinpoint stars (excepting the diffraction spikes), but the colour and contrast of the refractor.

Hence why I use both in my "stable" :)

Maybe reprocess the reflector image for better colour.

cometcatcher
11-11-2012, 07:52 PM
Except the processing is completely different. If you could perhaps put up a pic from each scope with no processing....

Larryp
11-11-2012, 07:56 PM
Even with the difference in processing, I definitely prefer the refractor image.

LewisM
11-11-2012, 08:24 PM
Not really - same workflow as usual actually.

ZeroID
12-11-2012, 07:13 AM
Have to say I prefer the reflector version. The refractor seems harsh and slightly bloated stars. The Reflector is softer, more natural looking and the stars are pinpoint.
May have something to do with processing differences minor though they may be or exposure values but I like the diffraction spikes. They don't detract from the image IMHO.

rmuhlack
12-11-2012, 10:17 AM
Isn't really an apples with apples comparison. Aperture is very different, as the Vixen (being a bigger light bucket) will collect 2.48x more photons than the NG per sub. This will impact on your SNR and affect the finished image even if workflow is the same.

As Brent pointed out, stars look bloated in the refractor image. Do you have a field flattener for the NG? Or perhaps it was just that your focus was off.

The VC200L (https://www.myastroshop.com.au/products/details.asp?id=MAS-066B2) is actually specced at f9, so I assume you're using some sort of focal reducer to get f6.4? Either way, focal lengths of the two scopes are also different, and this affects both image scale and guiding performance. Assuming you used your 5DII, the image scale is 1.03 arcsecs per pixel for the Vixen, and 1.93 arcsecs per pixel for the refractor.

Keeping all those things in mind, another image and equipment comparison when all the bugs have been ironed out of both systems would quite interesting.

Equipment issues aside, I much prefer the image from the vixen. Tighter stars, not as black clipped as the refractor image, and to my eyes a more 'natural' colour balance.

Visionoz
12-11-2012, 12:57 PM
I thought you had gotten rid of the VC200L and have now an R200SS instead?

Anyway like the others, I prefer the Vixen's results - much smoother and clearer

HTH
Cheers
Bill