ASKAR and SharpStar are the two brands from the SharpStar Inc,, I would assume the imaging quality is almost same to 76EDPH, with minor differences from the design of additional flattener vs flattener built-in? The prices are about the same as well.

The Askar FRA 400 Quintuplet Astrograph
#126
Posted 19 December 2020 - 07:09 PM
#127
Posted 19 December 2020 - 07:25 PM
#129
Posted 20 December 2020 - 01:02 AM
some cameras give uneven ADU values using bias frames or short exposures - plus if you have amp glow in flats this can also affect your processing
the idea of dark calibrating your flat files is that you remove any amp glow and you don't then use bias frames as you remove the bias from them using darks - I also do min 3 sec exposures and then this removes any issues of uneven ADU values
you end up with no amp glow in flats and even calibration of them.
You still use a full length dark in your processing but the flats use short exposure dark cals to remove any inconsistencies
cheers
Simon
thanks Simon, appreciate the comprehensive answer :-)
- ZL4PLM likes this
#130
Posted 20 December 2020 - 01:06 AM
been busy the last week with the FRA 400
Vela Supernova Remnant - A Southern Gem
This huge bubble of Hydrogen and Oxygen is all that remains of a huge explosion that cast star material across vast areas of the southern sky some 11000 years ago.
This single image represents only a small corner of this object which covers over 50 ly across. Lying some 800ly away from us it covers a large portion of our southern sky here in New Zealand.
ZWO ASI294MM Bin 1 - 40 x 600s HA 40 x 600s OIII @ Gain 120 (-20c) - 3nm Chroma
Askar FRA400 & Focal Reducer - CEM70 - Eagle 3
Shot over 3 nights - Processed entirely in Pixinsight
The 294mm in Bin1 is a fabulous match to the FRA400!
this is spectacular. What a wonderful image... amazing what can be done with a 72mm scope these days in the right hands and under NZ's darker skies. :-)
Edited by robonrome, 20 December 2020 - 01:07 AM.
- ZL4PLM likes this
#131
Posted 23 December 2020 - 04:55 PM
While practicing for the conjunction, thought I’d also practice a moon shot for Lunar X following the conjunction on the 21st. Taken with an ASI224MC , single shot, 0 gain, 0.001 seconds. I don’t think I was well focus, but gonna try again next time. This Askar’s a great scope for all occasion!
This looks really good rocketeer! I have a noob question, and am just getting into astrophotography. I got an Askar FRA400 a couple of months back and have started up the learning curve. I have started taking some deep sky shots of M31 and a few other Messier objects with "okay" results. I'm learning bias frames, stacking, and all of that. With the conjunction this past week, I tried some shots of Jupiter/Saturn with fuzzy results. I tested both with and without the reducer, and am using a Nikon D750 for my imaging. I know there are a lot of variables that can have an effect, but even though I could see both planets and four of Jupiter's moons, the results were fuzzy at best (Saturn was an oval disk, no clarity of rings). Even just observing with an eyepiece through the Askar did not seem sharp. Using our 8" dob right next to it, got great results (of course, a lot more light too). Is there anything I need to be factoring that I haven't thought of? The lenses do not appear dirty or cloudy. I did take some moon shots that seem to be on par with yours.
Thanks for your thoughts.
Lee
- astro rocketeer likes this
#132
Posted 28 December 2020 - 04:45 AM
This looks really good rocketeer! I have a noob question, and am just getting into astrophotography. I got an Askar FRA400 a couple of months back and have started up the learning curve. I have started taking some deep sky shots of M31 and a few other Messier objects with "okay" results. I'm learning bias frames, stacking, and all of that. With the conjunction this past week, I tried some shots of Jupiter/Saturn with fuzzy results. I tested both with and without the reducer, and am using a Nikon D750 for my imaging. I know there are a lot of variables that can have an effect, but even though I could see both planets and four of Jupiter's moons, the results were fuzzy at best (Saturn was an oval disk, no clarity of rings). Even just observing with an eyepiece through the Askar did not seem sharp. Using our 8" dob right next to it, got great results (of course, a lot more light too). Is there anything I need to be factoring that I haven't thought of? The lenses do not appear dirty or cloudy. I did take some moon shots that seem to be on par with yours.
Thanks for your thoughts.
Lee
Hi Lee, sorry for the late reply. I too am new to AP as I just started in late September this year and working my way up the AP learning curve. I too did try to image Saturn and Jupiter few nights before the actual conjunction (as I mentioned), but got pixelated images of Saturn and Jupiter using this scope and a mono cam. I'm very new to planetary imaging (and DSO) and just started to do planetary AP by prepping for conjunction and have not really thought too much about pixel scale from camera to telescope (but I should've). In my case in using the ASI174MM with ASKAR 400 imaging small planets resulted in being pixelated. I had a little coaching from Damian Peach and another friend who is a planetary imaging expert on my equipment set-up and said its likely under sampled. I ended up using my C11 EdgeHD instead for the conjunction and glad I did (though was first hesitant not to use it because I didn't think I could fit both planets fit in the same field of view with the camera, C11 + 0.7x reducer, but it did barely corner to corner). Since conjunction is over and pressure is off, I will start to try out more with planetary imaging with the ASKAR 400 using combinations of different cameras, barlows, and powermate just cause I'm curious and want to get ready for next years Venus and other planets coming through. I like the scope and want to make the most use out of this scope and will hope to share updates with this forum. In my opinion, I think planetary imaging with this scope can yield good results, but need to find the sweet spot between equipment set-up and planeatry position relative to imaging as well as software post processing. The two pictures shows results of the conjunction from both my ASKAR 400 (w/ ASI174MM) and C11 (with ASI224MC).
Another good reference I've found was this thread on CN (particularly post #8). Very nerdy, but keepin' it real and a good start which I need to get a better handle on too.
Edited by astro rocketeer, 28 December 2020 - 05:11 AM.
- pmuller likes this
#133
Posted 28 December 2020 - 04:50 AM
been busy the last week with the FRA 400
Vela Supernova Remnant - A Southern Gem
This huge bubble of Hydrogen and Oxygen is all that remains of a huge explosion that cast star material across vast areas of the southern sky some 11000 years ago.
This single image represents only a small corner of this object which covers over 50 ly across. Lying some 800ly away from us it covers a large portion of our southern sky here in New Zealand.
ZWO ASI294MM Bin 1 - 40 x 600s HA 40 x 600s OIII @ Gain 120 (-20c) - 3nm Chroma
Askar FRA400 & Focal Reducer - CEM70 - Eagle 3
Shot over 3 nights - Processed entirely in Pixinsight
The 294mm in Bin1 is a fabulous match to the FRA400!
the combination of the two - scope and ASI294MM Pro looks great!! You did a great job Simon! thanks.
#134
Posted 28 December 2020 - 05:02 AM
Here's the Pac Man Nebula I captured a few nights ago with the ASKAR 400 and 294MM Pro. This is my second time processing a narrowband image and am still learning how to use the camera and photoshop. Thought I should share how even an amateur like me could get some descent results with this telescope.
Lights:
S = 25x130 sec
H = 50x130 sec
O = 25x130 sec
Darks = 25
Flats = 25
unity gain 120, Bin 2 (but I should’ve used Bin 1 and didn’t realize it until I was already half way done imaging, but will try Bin 1 on same target soon as weather improve)
Edited by astro rocketeer, 28 December 2020 - 05:35 AM.
#135
Posted 30 December 2020 - 04:55 PM
First image with the FRA400 and my first foray into widefield AP.
Unfortunately light pollution and clouds meant jettisoning 3 hours of subs and only keeping 48 minutes worth, so there was a lot of noise and not much signal to work with. Many thanks to Ron Brecher (AstroDoc) for showing me how to best process such limited OSC data.
- RossW, astro rocketeer and robonrome like this
#136
Posted 31 December 2020 - 11:52 AM
Not to cause any debate or controversy but thought I’d share my experiment with using different cameras with the FRA400. When I used my Canon 60D Astro mod, ASI1600MM Pro and ASI294MM Pro (both mono with ZWO filter wheel), I had enough back focus adjustment from the scope to get focus (maybe about 15mm out), but when I used my ASI071MC Pro with the ZWO filter drawer (and ZWO Duo Narrowband Filter) I couldn’t get focus even to the farthest distance off the scope focus reel and looks like the focus barely makes it. I had to add in a 20mm spacer and still drew back almost to about 31mm in addition to get it to focus. This is for anyone reading who might be thinking about same setup. I’m new to AP and still learning a lot by trial and error and from all the knowledgeable CN’ers here. Here’s a pick of the ASI071MC Pro setup with the FRA 400 + 0.7x reducer
It is important to note that this is spacer arrangement provides you with the incorrect and therefore suboptimal correction for this scope.
For the FRA400 reducer, the required backfocus is 55mm. In your case you would connect the 071MC/FD/16.5mm spacer. This gives you 17.5+21+16.5=55mm.
The amount of focuser drawtube is irrelevant to the optical arrangement.
- RossW and astro rocketeer like this
#137
Posted 31 December 2020 - 11:57 AM
It is important to note that this is spacer arrangement provides you with the incorrect and therefore suboptimal correction for this scope.
For the FRA400 reducer, the required backfocus is 55mm. In your case you would connect the 071MC/FD/16.5mm spacer. This gives you 17.5+21+16.5=55mm.
The amount of focuser drawtube is irrelevant to the optical arrangement.
Thanks RogeZ. Would the 55mm be same without reducer?
#138
Posted 31 December 2020 - 03:07 PM
Think of the focuser as a variable extension that can provide more or less length depending on your image train.
I replaced the conical adapter for a Baader M68 60mm extension for better illumination of the 6200MM.
- Gene3 and astro rocketeer like this
#139
Posted 10 January 2021 - 06:09 PM
Anyone using this scope with a full-frame camera? Wondering if it's a good, airline portable, match for my Canon 6Dm2.
Mike
#141
Posted 12 January 2021 - 10:28 PM
Thanks Roger. I had already seen your image on AB and it looks great. But how do the stars in the corners look in uncropped frames?
Mike
#142
Posted 12 January 2021 - 11:29 PM
Thats as uncropped as it gets.
i only crop to remove the “dither band”. Not much.
Edited by RogeZ, 12 January 2021 - 11:30 PM.
#143
Posted 13 January 2021 - 08:42 PM
Anyone using this scope with a full-frame camera? Wondering if it's a good, airline portable, match for my Canon 6Dm2.
Mike
I posted full-frame ASI6200 images in post #24. No vignetting at all and stars look good in the corners at f/5.4. Those images were taken with a poorly adjusted tilt adapter too. I have not yet tried to use the reducer.