Newton collimation Catseye Collimation CATSEYE Collimation System · eric belanger · ... · 5 · 163 · 0

Hello . 

I have a question about collimation .
Im gonna make this very simple .

I have a quattro 200p with starizona coma reducer , so im at F3 .
I collimate using a laser and that's it . I dont double check on a star . Obviously i dont have perfect stars but i dont really care because of tools like blurx ! 

My question is : since i use blurx to correct my stars , does it make collimation less important ?

Does a perfect collimation increase quality of the image overall or it's just for the stars ?

Thanks all

Yes, software can help with bad data but it's not that simple. Collimation is important not just for star shapes. While BlurX might give you round stars, it's not doing anything to correct the loss of definition in the non-stellar parts of your image. Contrast and definition will degrade the further out of collimation you are. Not getting the absolute best you can from every aspect of your equipment leads to mediocre results. I can't understand why that would be a goal that anyone would aspire to.

Properly collimated Lasers are ok for getting optical collimation in the ball park but a center of field, high magnification star test is the gold standard. There isn't any reason to be lazy about collimating a Newtonian, it's not difficult and if your mirror mount is decently designed, you shouldn't have to do it very often if the OTA is handled with a reasonable amount of care. If you have to transport for every session collimation it should be checked but again, only small adjustments taking a min. or two should be needed.

If all of that is too much then a Newtonian reflector is not for you and it's time to trade in for a refractor.

Tony Gondola:
While BlurX might give you round stars, it's not doing anything to correct the loss of definition in the non-stellar parts of your image. Contrast and definition will degrade the further out of collimation you are.

Hello - it is not accurate to say that BlurX does not correct the non stellar parts of an image. It absolutely does. It is obvious to those of us that have used it and Croman says so as well:

"BlurXTerminator can apply different amounts of deconvolution to the stellar and nonstellar features of an image. Trying to recover all of the detail available in nonstellar, extended objects using the classical algorithms usually results in dark halos (ringing) around stars. With BlurXTerminator, more sharpening can be applied to the nonstellar parts of an image, bringing out more detail without producing ringing artifacts in most cases.BlurXTerminator can additionally correct for other aberrations present in an image in limited amounts. Among those currently comprehended for most instruments are:

• First- and second-order coma and astigmatism
• Trefoil (common with pinched optics and in image corners with some camera lenses)
• Defocus (poor focus and/or field curvature)
• Longitudinal and lateral chromatic aberration
• Motion blur (guiding errors)
• Seeing/scatter variation per color channel
• Drizzle upsampling artifacts (2x only)

These aberrations are not assumed to be stationary: they can vary across the field of view. This is a major advantage over most implementations of the classical deconvolution algorithms, which assume that the same PSF applies to the entire image. For example, stars with limited comatic profiles in the corners of an image will be made round and then sharpened, while stars in the center that are already round will simply be sharpened. This correction can be applied to the nonstellar features in an image, too. Correction can be done as a separate step, or in combination with sharpening."

That said, proper collimation is still important, since it gives BlurX a much better starting point. Croman is clear that his tools are not a substitute for good practices like collimation, but rather a complement to them.