Sharpstar 150 F2.8 HNT astrograph

[tooth_dr]

4 minutes ago, gorann said:

You need the Baader UFC Universal Filter Changer System made for the RASA - FW is not possible.

https://www.firstlightoptics.com/baader-filters/baader-ufc-universal-filter-changer-system.html

Nifty! As long as you don’t mind getting out of bed to swop over filters!

[Adam J]

On the subject of sharpness I have often looked at shots from very fast scope <f3 like RASA etc and thought that they are not so sharp as what I see from a refractor. Might just be my impression mind you with all the different possible combinations of camera etc it's had to be sure. 

[gorann]

4 hours ago, Adam J said:

On the subject of sharpness I have often looked at shots from very fast scope <f3 like RASA etc and thought that they are not so sharp as what I see from a refractor. Might just be my impression mind you with all the different possible combinations of camera etc it's had to be sure. 

I think you could be right - at least a big refractor wins in sharpness but loses in FOV and speed. I doubt that a 400 mm FL refractor would be much sharper that a 400 mm FL RASA unless possibly you go for really long integration times with the refractor. With the same integration time the S/N ratio of the RASA should be much better. But if I do a mosaic with my Esprit 150 with relatively long integration time, it would proably be sharper and more pleasing to pixel peepers, but after Tomato @tomato saw my RASA 8 image of M31, he gave up his plans of doing an M31 mosaic with his double Esprit 150 rig and bought a RASA 8! When weather is like it is, then speed is an important factor.

 

Edited September 8, 2020 by gorann

[Davey-T]

1 hour ago, gorann said:

You need the Baader UFC Universal Filter Changer System made for the RASA - FW is not possible.

There is a member on here who has constructed some sort of OAG / filter wheel I believe but not seen it in action.

Dave

Edited September 8, 2020 by Davey-T

[gorann]

I dont think a FW could ever be fitted infront of a RASA 8. Maybe on a RASA 11 or the astronomically expensive RASA 14. but it would be quite an obstruction. With a FL of 400mm, an OAG is really not needed, a guidescope is good enough. One way of doing it with a slider would be to collect RGB before you go to bed and then let it collect Lum for the rest of the night. My plan is to do bicolor HaOiii by swapping filters just before I go to bed.

[tomato]

With the RASA at F2 and a 3.8 micron pixels I’m imaging at nearly 2 arcsec per pixel, and don’t need to run the  camera at full cooling, so I can’t see warm air from the camera being a big problem, but I’ll keep you posted.

The Hyperstar seems a bit too highly strung for me, but that’s only based on what I have read, I have no direct experience. 

[gorann]

25 minutes ago, tomato said:

With the RASA at F2 and a 3.8 micron pixels I’m imaging at nearly 2 arcsec per pixel, and don’t need to run the  camera at full cooling, so I can’t see warm air from the camera being a big problem, but I’ll keep you posted.

The Hyperstar seems a bit too highly strung for me, but that’s only based on what I have read, I have no direct experience. 

I never heard it mentioned as a problem by someone having a RASA. As I said the heat from the camera works to your advantage by slightly heating the corrector lens so you do not need a heater, just a dew cap (although I still have to see what happens when I get into sub zero temperatures in a few months).

[CCD-Freak]

A buddy of mine makes a curved cable router for Hyperstar and RASA scopes.

https://jwbozeman.com/shop?olsPage=products%2Fhyperstar-cable-router

 

 

John Love
CCD-Freak
WD5IKX

[gorann]

20 minutes ago, CCD-Freak said:

A buddy of mine makes a curved cable router for Hyperstar and RASA scopes.

https://jwbozeman.com/shop?olsPage=products%2Fhyperstar-cable-router

 

 

John Love
CCD-Freak
WD5IKX

Yes. that will elliminate any diffraction spikes, so go for it if you settle for a RASA. I made mine from garden-plant wire and electric tape, but your fiend's alernative looks more professional and 15 USD is not much to complain about. Regarding heating from the camera I never heard it would be a problem and maybe the camera fan just creates enough air flow to dissipate any gradients that could act optically. Just like fans at the back end of RC and Newtonean telescopes.

[DaveS]

Interesting Baader filter holder system, but after my year long saga of the non-appearing Baader 2" H-alpha filter I'd hesitate to order any Baader item that didn't have a green lorry symbol.

[gorann]

38 minutes ago, DaveS said:

Interesting Baader filter holder system, but after my year long saga of the non-appearing Baader 2" H-alpha filter I'd hesitate to order any Baader item that didn't have a green lorry symbol.

Well, this is the situation with everything since Corona, and with filters everything is made in batches. If you go into the TS site you can at least get a dlivery date (15 Oct for my Oiii, although I have them ordered from FLO). I have the Ha and I just ordered the Sii that is on its way in the mail (saw that TS had them and  ordered now to be safe before it runs out).

[DaveS]

I've had a long email exchange with FLO over this, ending in my sending the original filters (Plus a 7nm H-alpha) back for a refund, and ordering the equivalent Chroma set. Sorry, don't want to derail the thread so I'll bow out.

[gorann]

3 hours ago, DaveS said:

I've had a long email exchange with FLO over this, ending in my sending the original filters (Plus a 7nm H-alpha) back for a refund, and ordering the equivalent Chroma set. Sorry, don't want to derail the thread so I'll bow out.

I would not mind Chroma filters for my other scopes and cameras but they will not work on fast scopes like the RASA. Only Baader seem to bother making such filters, and In this case it is probably not a Corona issue since Baader as I understand it make their filters in Germany - they just need to produce a batch that passes their QC.

[CCD-Freak]

Well....I pushed the BUY button and it arrived yesterday.  The weather forecast actually looks pretty good for fist light this weekend. 

I want to get it all checked out before my imaging expedition to SW New Mexico in October.  Imaging at F2.8 under Bortle 2 skies should be a blast!

John Love
CCD-Freak
WD5IKX

[CCD-Freak]

I installed an EAF focus motor on the SS 15028HNT today and it looks great with all the red. 

I then tweaked the collimation that was just slightly off after shipping.  Collimating with the laser was a 10 minute job.

Now I will mount my guide scope and get it ready to go on the mount.

 

Looking forward to testing it if the weather clears as forecast this weekend.

John Love
CCD-Freak
WD5IKX

[Davey-T]

Trying to get  mine reasonably balanced I moved the rings as far forwards as I could but the had to make another bracket for the focuser and fit on the other knob.

Dave

 

[CCD-Freak]

Looks good....I like the custom brackets. 

I will be working on getting mine mounted on the AP900 today and mounting the guide scope.

 

John Love
CCD-Freak
WD5IKX

Edited September 17, 2020 by CCD-Freak

[CCD-Freak]

This is one of the reasons I chose the SS 15028HNT over a RASA system...

https://www.cloudynights.com/topic/716612-its-a-sad-day-when/

OUCH !!!

I an working on mounting my guide scope today.

John Love
CCD-Freak
WD5IKX

[Davey-T]

29 minutes ago, CCD-Freak said:

I an working on mounting my guide scope today.

Bolted my tiny guide scope to the handle, had to put a shim under the front end to align it approximately to the main scope.

Dave

[CCD-Freak]

The 80mm Stellarvue guide scope went on today quite nicely.  

I am just about all set for the trip to a park about 100 miles from home.  I may have some issues with all the smoke blowing in from the California wild fires.

 

John Love
CCD-Freak
WD5IKX

[Davey-T]

I see you mirror locking  screws protrude from the rear end, according to reviews I've read all the mirror screws are below the rear end to allow the scope to be stood on it.
Took mine apart and if the locking are screwed in far enough to get them below the rear rim the actual adjusting screws are nearly out of thread, I bought some shorter locking screws for mine.

Dave

[tomato]

17 hours ago, CCD-Freak said:

This is one of the reasons I chose the SS 15028HNT over a RASA system...

https://www.cloudynights.com/topic/716612-its-a-sad-day-when/

OUCH !!!

I an working on mounting my guide scope today.

John Love
CCD-Freak
WD5IKX

Yup, that RASA will need a bit more than just collimation. Not a good idea to snag cables of any description.

Good luck with your dark sky trip.

[CCD-Freak]

Here is the SS15028HNT set up for imaging at a campground about 100 miles from home.  The sky was hazy with smoke from the west coast wildfires but there were no clouds for one night so I got to shoot some test images with my ASI 533MCP.   These test shots were NGC6992  (50x2 minute subs)  NGC896 (20x2minutes subs) M33 (30x2 minutes subs) through smoke.  I am still working to get the collimation "spot on" but I think I am really going to enjoy this little astrograph once I get everything dialed in.

 

John Love
CCD-Freak
WD5IKX

Edited September 24, 2020 by CCD-Freak

[Davey-T]

Looking good John are you sure the mount can handle it 😆

Dave

[gorann]

Yes, looks promising John! The stars look a bit squarish to me - is that a collimation issue?