My first guided image

[MikeWilson]

9 subs of 5 minutes each at ISO800. Bias images used but no darks or flats. Processed in Photoshop.

Scope: Skywatcher 150P

Mount: HEQ5 PRO

Guiding: ST80 with Skywatcher SynGuider

Camera: Canon 1000D (unmodified) with CLS-CCD clip filter and MPCC.

A few of us are experimenting with the Synguider on this thread over yonder: http://stargazerslounge.com/equipment-help/116834-synguider-through-finderguider-problems-4.html

I owe a thanks to several people but especially thanks for the advice in equipment choice and experiences from AndyUK, Psychobilly, SlySi84 and Steppenwolf.

EDIT: Seeing is dreadful tonight and M45 was only *just* visible to the naked eye. The sky is slightly foggy and the moon is out and very bright.

[AndyUK]

Hi Mike - I'd be REALLY pleased with that as a "!first light" with the synguider. A few darks (flats?) subtracted and remove the gradient and I reckon that would make an excellent shot... Not a trail in sight!

[MikeWilson]

Hi Mike - I'd be REALLY pleased with that as a "!first light" with the synguider. A few darks (flats?) subtracted and remove the gradient and I reckon that would make an excellent shot... Not a trail in sight!

Thanks Andy.

It was first light for the Synguider and the ST80. I'd only made my parfocal eyepiece earlier this night. Hopefully we can get you up to your first guided image soon, too

[AndyUK]

Hmmm... I think I'm going to need guiderings, which means waiting for another pay-day, but I WILL get there sometime soon!

[MikeWilson]

Hi Andy,

A lot of people guide with an ST80 piggybacked without guiderings. How does the ST102 compare with the field of view? Does it have a longer focal length?

[Photosbykev]

I'd be happy with that image, no visible trails which is the key thing. The rest of the processing images to clean up the gradient etc are just the next step

I've just ordered a set of 100mm guide rings and vixen mounting plate from FLO for my ST80. They should allow me to accurately align the guidescope and imaging lens when they are side by side on a ADM SBS adaptor.

[Beyond_Vision]

Well done Mike looks like the guiding is ssussed out.

Kev the guide scope doesn't need to be co-aligned with the imaging scope.

Regards

Kevin

[AndyUK]

Hi Mike - The 102 has a FL of 510mm, which isn't a great deal bigger than the ST80. I probably could get by without guiderings and just have normal rings, but as my 100ED has a clamshell, I'd need to buy 2 dovetails and 1 set of rings to mount the guidescope... and I still have concerns that I may need to choose an "un-named" star (mag 6 or 7) in order to achieve longer exposures (c. 2s).

This would probably require me to manually centre/lock the guidestar, as I'd assume that the synguider would pick the brightest star in its FOV with an autolock, which may be too bright to be able to provide the best tracking...

Also in the mix is the fact that I'd like the option of being able to guide my camera direct on the mount and I already have a dovetail with a manfrotto quick release for this (I've taken 5 min unguided with a 12-24 lens, but this isn't enough for what I want to do). So, the best/easiest way to fit this would be a dual mount, but if I go down this route, I'd only need one dovetail and one set of rings (for the guidescope) but of course the dual-mount is a tad expensive (as are guiderings!)... Decisions, decisions...!

[Photosbykev]

Well done Mike looks like the guiding is ssussed out.

Kev the guide scope doesn't need to be co-aligned with the imaging scope.

Regards

Kevin

I agree with you but my engineering background make me want to align them It's just wrong if they aren't, just like having the finderscope and guidescope not aligned.

BTW Andy, the ADM SBS system is expensive but damn it's strong, I've used weaker crowbars

[ollypenrice]

I agree with you but my engineering background make me want to align them It's just wrong if they aren't, just like having the finderscope and guidescope not aligned.

BTW Andy, the ADM SBS system is expensive but damn it's strong, I've used weaker crowbars

Hmmm, but my strictly amateur engineering background (hammer, nails, glue and acts of violence...) says that a bolted down ST80 is less prone to flexure than one perched between six opposing points pressing on a thin tube. Also if you are imaging a bright large object then you are pointing your guidescope straight at it, risking low contrast in your guidestar search. Of course, with rings you can always point it away a bit. Ah! So why align it in the first place? I set mine a little off axis for this reason.

Olly

[Photosbykev]

I haven't managed to get the QHY5 on the back of the ST80 guiding yet so it's a mute issue until I do

[simon84]

Well done Mike, nicely done. Its good to see someone trying something out, sticking with it and then getting it to do what they want.

I agree that the guidescope needs to be pointed away from your target. Imagine imaging M31 with your guidescope pointed straight at the centere. I'd image your chances of a guide star would be pretty slim.

I have my finder/guider mounted in either a finder scope bracket or a small set of guide rings bolted to the top of the tube ring. Using the latter if I'm imaging something low in the sky the Canon can deal with the sky glow because of the CLS filter but the QHY5 will struggle, but because the dovetail and rings are secured using a single screw into the tube ring I can in theory, not needed to do it yet, rotate the finder/guider through 360 degrees to find the best bit of sky.

[themos]

If you are guiding on a star away from the centre of the main imaging field, you risk getting field rotation that is amplified by your polar alignment error.

[Deneb]

Congrats on your 1st guided image, im sure there will be more to come.

Nadeem.

[AndyUK]

Hi Kev

BTW Andy, the ADM SBS system is expensive but damn it's strong, I've used weaker crowbars

That's what I'm looking at, with the ADM guiderings...

[MikeWilson]

Thank you everyone for your encouraging comments. Regarding flats, I actually quite like the vignetting on this one. It almost feels like a Christmas card (I might even make it into a Christmas card!).

The ST102 seems to have a smaller field of view than the ST80 but the flipside to that are brighter stars.

However, Andy, before you plunge towards the ADM rings set wait until you've had a go of a few targets with a fixed scope. I expect that you'll find the Synguider will guide acceptably on most of the targets you're looking at. And, as Olly and Thermos have said - a strong single mount will be less prone to flexure and field rotation.

I'm looking forward to your first light image, Andy!

@Photosbykev - I love the photos on your site, particularly the foreground big digger with the field rotation apparent in the background. My three year old son loves diggers and the stars and I like the stars Mind if I print a copy for him?

@Nadeem - As much as I thought you stuck out unguided imaging for so long, I'm not sure long unguided exposures are for me! I really struggled to get long exposures without field rotation at all.

[Photosbykev]

Help yourself Mike, thank you for asking

[AndyUK]

Hi Mike - Yes... I've been thinking whilst walking the dog this afternoon. Although expensive, I think I've almost decided on looking at this in 2 stages:

1. ADM dual mount - I can then at least mount the two scopes and synguider without having to buy anything else and see how I get on with a "fixed" guidescope. In addition, it will also enable me to mount my 40D on its dovetail/quick release and have THAT guided too (either wide field or 200-300mm)...

2. If necessary, I can then look at getting the guiderings.

(Quick - Where's my credit card, before I change my mind! )

[Photosbykev]

Hi Mike - Yes... I've been thinking whilst walking the dog this afternoon. Although expensive, I think I've almost decided on looking at this in 2 stages:

1. ADM dual mount - I can then at least mount the two scopes and synguider without having to buy anything else and see how I get on with a "fixed" guidescope. In addition, it will also enable me to mount my 40D on its dovetail/quick release and have THAT guided too (either wide field or 200-300mm)...

2. If necessary, I can then look at getting the guiderings.

(Quick - Where's my credit card, before I change my mind! )

nothing to stop you using a tripod head, either geared or a ball & socket for mounting the camera with the shorter lenses

[MikeWilson]

Hi Andy,

Here's what I have:

1. A Skywatcher Dovetail. £15 from FLO

2. An ADM clamp. £20 from FLO

And what I get:

1. A solidly mounted piggybacked scope that in theory can be rotated about it's single screw. Not like I can rotate it in practice since I've screwed it into position so tight it's not moving for anything.

2. Easily removed (simply unscrew the retaining ring, pop the ring open and remove the guidescope.

I think that I get most of the benefit of guiderings without spending the extra £100 or so to get them.

Your mileage may vary, but I would like to encourage you to at least try a fixed guidescope first. If you haven't given up on the finder/guider experiment (which I believe is probably doomed with the synguider - not so with a laptop+QHY5), then definitely don't give up on the fixed guidescope.

Unless you have your heart set on the ADM system, of course.

[AndyUK]

Hi Kev - To be honest, the really widefield stuff is comparatively easy. I have a 12-24mm lens and I've been able to get 5 mins exposures from this no problem... However, with the 100ED being 900mm/f9, I've had some fun with my 180mm/f4 (which with the 1.6x factor becomes c. 290mm), and it's this that I'd like to have the option to use more...

Mike - Yes, I certainly could go for a cheaper option, but for my setup I'd need to buy 2 dovetails and 2 sets of rings. Unfortunately the 100mm ED has a clamshell and the 102 only has a 3" dovetail which is screwed direct into the OTA (it came with an AZ goto mount), so the combined cost would be £70... vs £145 for the ADM dual mount (which would also give me the additional option of easily attaching my existing "DSLR" dovetail with manfrotto quickrelease).

If I went for the cheaper route, I'd have to retire the clamshell and if I then discovered I wanted/needed guiderings, I'd also then have a set of redundant tube rings as well. Okay, it's only £35 (of which I could maybe recoup £20), but there's also the hassle factor as well... added to which it wouldn't be so easy to attach my "DSLR" dovetail.

Assuming I go for the ADM dual mount, it would certainly be my intention to try using the guidescope without rings first (and hopefully save a further £85)... but regarding the finderguider experiment, whilst I would certainly agree with you that using a stand-alone unit would appear to be much more difficult than using one on a guidescope, I still haven't totally given up on that yet... (although I probably should...!). I think I'll sleep on it...

[Photosbykev]

The really wide angle imaging isn't a real problem like you've said. I've been playing with a Canon 600mm f4L prime lens which is a bit of a challenge It's also another minor reason for selecting the guide rings for the ST80 as it improves the balance with the ADM SBS adaptor as it increases the mass on the ST80 side of the adaptor.

Even with the SBS adaptor offset to put the 600mm as close to the centre line as possible it is still heavier than the ST80. The Canon 5D MkII and the 600mm is around 7 kgs, not that heavy but heavy enough.

[AndyUK]

Hi Kev - I've just noticed your lens and camera collection - That's some VERY serious kit you have there [ENVY!], and your camera/lens combination @ 7 kgs would be over half my CG5 load capacity alone .

I must admit I hadn't considered the side-by-side balance, but now that you've mentioned it, (and if I've got my sums right), with the 102 / 100ED combination in imaging mode, I'd have a 2.3Kgs differential towards the 100ED without the 102 in guiderings, but with the 180mm set up, the balance would be a lot closer (). Thanks for getting me to check this...!