Sadre with SA and 90mm

[DaveS]

My first "proper" run with the Star Adventurer after sorting out the PA and RDF alignment.

Leitz 90mm f/2 Summicron R, ASI 183 MMC and Baader HII filter (Just what I had in the wheel at the time).

The first image is a stack of 12 x 60 sec exposures, just the light frames as I wasn't trying to make a good image.

The second is a single 5 min sub, also given a stretch to show the significant trailing.

The orientation is roughly vertical, again this was just done by eye when assembling the rig. Without mount control I can't do the usual trailing method for orientation.

 

[Davey-T]

What focal length does that equate to Dave ? I get confused working with camera lenses.

I can do 90 secs reliably on my SWSA using a DSLR and 300mm f/4 lens and 10 minutes using 24mm. ( only from a dark site otherwise I end up with a white picture)

I guess it depends where your aiming.

Dave

[souls33k3r]

The first 12 x 60sec image looks beautiful mate.

[DaveS]

It is 90mm FL, and 45mm clear aperture.

I *thought* the SA was capable of longer exposures / longer FL, it looks like my PA needs more work. I have Polefinder on my smartphone, but didn't use it this time, just the SW alignment routine from the manual.

Do you know if the QHY Polemaster can be used on the SA? I find squinting through the polar scope very difficult with my varifocal glasses.

[souls33k3r]

3 minutes ago, DaveS said:

Do you know if the QHY Polemaster can be used on the SA? I find squinting through the polar scope very difficult with my varifocal glasses.

Yes you can. You'll just need to buy an adapter for it.

https://www.modernastronomy.com/shop/accessories/polemaster-adapter-for-star-adventurer/

[Jkulin]

Dave, I use my polemaster fitted in my SA and it fits and works perfectly.

I was getting 7 1/2 mins unguided last year and it was near enough perfect but that was with a 14mm F2.8 lens, for that reason I went and got it hypertuned but haven't used it since to compare.

[DaveS]

Thanks, I'll put a polemaster and SA adaptor on my shopping list for when I come back from holiday.

I did have a look on @FLO site but couldn't see the adaptor.

@Jkulin Where did you get your SA hypertuned? I may be wanting to use mine with something in the 300mm range.

[DaveS]

Thinking about the 5 min image, I think I pulled the aperture down to f/4 to avoid Sadre burning out and bloating.

[FLO]

13 minutes ago, DaveS said:

I did have a look on @FLO site but couldn't see the adaptor.

We appear to have overlooked that one. Sorry ?

Will add it ASAP

[souls33k3r]

Just now, FLO said:

We appear to have overlooked that one. Sorry ?

Will add it ASAP

Awesome, i did look at FLO website first but couldn't find it so mentioned a competitor's link instead.

[FLO]

No problem. It is posts like yours that keep us on our toes ? 

Steve 

[DaveS]

9 minutes ago, FLO said:

We appear to have overlooked that one. Sorry ?

Will add it ASAP

That's great. Will put in an order when I come back from my hols.

[FLO]

I have just spoken with my colleague. We haven't overlooked it, he has requested a Polemaster adapter for Star Adventurer a number of times and each time QHY (the manufacturer) sent us their adapter for Astrotrac. It does work (fits to the dovetail) but is not ideal and certainly not elegant. It appears QHY don't yet have a purpose-made adapter. If another retailer is offering one then it is probably the one for Astrotrac, or they might have made their own adapter. We will look into making a FLO adapter but it will take a while. 

HTH, 

Steve 

[Helen]

Nice Dave ?  I'm just starting my SA journey too.  My first proper test led me too to thinking about how to avoid being on my knees squinting with varifocals through the polar scope!

The adapter for attaching my 135 Samyung lens to the asi1600 arrived this morning.  (But as usual nothing is straightforward - I have a Sony mirrorless camera and so the lens has a very short distance between the rear and the chip... so no chance of getting a filter wheel in there... ho hum!)

Helen

[DaveS]

28 minutes ago, FLO said:

I have just spoken with my colleague. We haven't overlooked it, he has requested a Polemaster adapter for Star Adventurer a number of times and each time QHY (the manufacturer) sent us their adapter for Astrotrac. It does work (fits to the dovetail) but is not ideal and certainly not elegant. It appears QHY don't yet have a purpose-made adapter. If another retailer is offering one then it is probably the one for Astrotrac, or they might have made their own adapter. We will look into making a FLO adapter but it will take a while. 

HTH, 

Steve 

Ah, that makes sense.

Examining the MA photo it looks like their one screws onto the second 3/8 inch stud on the dovetail.

[DaveS]

Getting another 18 subs of 90 sec to add to this. Going on holiday to Dorset (Near where I'll be moving to. Irony) shortly so will try to get some RGB to add to this, unless I bung [OIII] and [SII] filters in the wheel for a HST image. Or maybe just the [OIII] for a HORGB image.

[DaveS]

I can't believe I've been so stupid.

Turns out I had the filters swapped in the wheel, so what I thought was H was actually L. So I ended up getting 30 useless L subs from a horribly light sky instead of the H that I could use in a HRGB.

Wondered why Sadr was so big.

[Jkulin]

21 hours ago, DaveS said:

@Jkulin Where did you get your SA hypertuned? I may be wanting to use mine with something in the 300mm range.

Hi Dave, It was dirt cheap to get done at Dark Frames, I think it was £100odd, I've been tied up most of the year with weekend shows, so not got away much, but hopefully with an Isle of Man Trip in October I can have a bash

 

5 minutes ago, DaveS said:

Turns out I had the filters swapped in the wheel, so what I thought was H was actually L. So I ended up getting 30 useless L subs from a horribly light sky instead of the H that I could use in a HRGB.

Been there done that and even did it with the wrong filter wheel fitted, i.e. NB instead of LRGB, you'd think I would have learnt.

Dave I bought my Polemaster adapter from Modern Astronomy, here's the link: - http://www.modernastronomy.com/shop/accessories/polemaster-adapter-for-star-adventurer/

[newbie alert]

A friend just did 90 min ha sub with a 16mm lens with his S.A. as he thought he could push his 45 min data further.. 

[Jkulin]

BTW this was a 450sec image that I took last year with my SA, unguided just outside of Le Mans, unbalanced but with excellent polar alignment, I haven't processed this at all, this was straight out of my D800, I only wish I had used an ISO of 3200 and I would have had some beautiful detail, but you live and learn. It was with my Samyang 14mm F2.8 lens though.

Oh and some flats woudln't have gone amiss either?

[DaveS]

Well, this is the entire data set, 12 x 60 sec + 18 x 90 sec Luminance (D'oh!), which I make 39 min, at f/2 with the 90mm Summicron-R. Lights only as I haven't got bias, dark or flats for L yet.

Sigma Add stacking in AA5, then Gradient Removal followed by several rounds of gentle Histogram Stretch.

Looks like a touch of amp glow in the corners, to be taken out with Darks later. North is to the left I think.

The sky was even lighter when I took the last 18 subs, as I thought I was getting HII so wasn't too worried. Dur....

Although I won't add to this data set, I think I'll keep it to use as an L layer when I get the RGB, HII, and [OIII] data as I've now added an [OIII] filter to replace the L.

[FLO]

On 11/07/2018 at 12:21, FLO said:

I have just spoken with my colleague. We haven't overlooked it, he has requested a Polemaster adapter for Star Adventurer a number of times and each time QHY (the manufacturer) sent us their adapter for Astrotrac. It does work (fits to the dovetail) but is not ideal and certainly not elegant. It appears QHY don't yet have a purpose-made adapter. If another retailer is offering one then it is probably the one for Astrotrac, or they might have made their own adapter. We will look into making a FLO adapter but it will take a while. 

Until QHY make one dedicated for the Star Adventurer we will do the same as Modern Astronomy (offer the adapter designed for Astrotrac) but have added a note explaining it is a compromise. 

QHY PoleMaster Adapter for Star Adventurer 

HTH

[DaveS]

Thanks.

Will put a basket togethet when I come back from my hols. If I have any money left .