Comparison between Hyperstar and F10 imaging

[HunterHarling]

Hi all, I finally got around to doing this, here it is:

The first is with my Edge HD 800 at F10, the second is with hyperstar cropped, and the third is the Hyperstar full field. The camera is an ASI1600MM PRO and the filter is Ha. THE HYPERSTAR IMAGE IS 30 SECONDS AND THE F10 IMAGE IS 240 SECONDS!

I think Starizona got it right in that Hyperstar is "Faster" lol! It required 8 times the exposed in the F10 image to get the same signal.

However, the detail in the F10 image is incredible compared to Hyperstar, so there is a trade off. Also, the collimation in the Hyperstar image is off.

Enjoy!

[vlaiv]

In my view - no contest at all

Hyperstar is just not diffraction limited - even when you fix collimation, you will find that stars will be "bloated" and there will be "softness" to the image. It does have it's place however - fast capture of wide field images (that you will not display at full resolution )

 

[Rodd]

You really can't compare an F2.8 image and a F10 image.  They are different animals.  One is widefield and one is closer in.  Even when you use a .7x reducer on a refractor, you can't zoom in and crop and compare it with the refractor at native focal length--the zoomed in image will ALWAYS be inferior to the native viewing of 1:1.  You ues a reducer to get a wider FOV and you use hyperstar to get a REALLY wide FOV.  While it is true that the hyperstar image is not as sharp as the F10 image when zoomed--it is also true that the F10 image CAN"T display what the hyperstar image can display--the data is just not there beyond the FOV.

So, not sure what the point is, other than saying than obviously my FSQ 106 image of M104 will not be as detailed as my C11Edgeimage of M104.  I have to zoom the FSQ 106 image beyond what the data can support in order to make the comparison.

Rodd 

[wornish]

Your post has saved me lots of money thanks.

[pete_l]

Yes, with Hyperstar collimation is tricky and perfect focus even more so.

But this is a case of horses for courses. There are some DSOs that merit such a wide field, but there are thousands more that don't need it. And there are other ways (camera lens) of achieving the occasional widefield view of bright targets. Just like a Ferrari can be criticised for lacking luggage space, that isn't what you buy it for ?

[RobertI]

An interesting comparison and pretty much what I would have expected. Hyperstar is not just wide field of course, when used with a C11 or C14 you are getting a decent focal length too, but images in a fraction of the time which is perfect for alt-az imaging, EAA, outreach, etc. I think the best Hyperstar images I have seen are from Greg Parker and the near real time images from @HiloDon with a C14 and Hyperstar are amazing (see his gallery on SGL).

[Chris]

What this tells me is that the 0.7 reducer for the Edge is a very good compromise. I'm impressed that you've got so much data at f10 for just 240 seconds, but those ASI1600's are pretty incredible. 

[HunterHarling]

On 26/06/2018 at 10:34, Rodd said:

So, not sure what the point is

The point is to show a direct comparison between F10 and Hyperstar, and that it will hopefully help people.

Both Hyperstar imaging and long focal length are great, and I love imaging with both.