Skywatcher 80ED pro or Skywatcher 150PDS?

[GuillermoBarrancos]

Is there much work involved in converting a 9x50 into a guide scope with a QHY5L?

I bought this one from TS alongside my QHY5L-IIc. It has a 1.25" helical focusser, so the camera fits right in.

http://www.teleskop-express.de/shop/product_info.php/info/p4064_TS-50mm-straight-viewfinder-and-mini-guiding-telescope-with-bracket-and-1-25--focu.html

Tho, Modern Astronomy (who also sells the QHY cameras in UK) also has finder guider packages available. So you can check there too.

[ianpwilliams]

So if the advantages of using a 9x50 as a finder/guider are that you can save money and weight due to not needing to buy an ST80, what are disadvantages of doing it (I'm assuming there must be some)?

Regarding the QHY5L-II, it looks like this would be the way to go (either with an 9x50 or an ST80):

http://www.modernastronomy.com/camerasGuider.html#QHY5L-II

Would people recommend the colour or mono version? And would it be worth going for the "All Sky Lens" or "Premium Package" options (prices range from £184 to £329)?

[GuillermoBarrancos]

So if the advantages of using a 9x50 as a finder/guider are that you can save money and weight due to not needing to buy an ST80, what are disadvantages of doing it (I'm assuming there must be some)?

Regarding the QHY5L-II, it looks like this would be the way to go (either with an 9x50 or an ST80):

http://www.modernastronomy.com/camerasGuider.html#QHY5L-II

Would people recommend the colour or mono version? And would it be worth going for the "All Sky Lens" or "Premium Package" options (prices range from £184 to £329)?

The ST80 has ofcourse more aperture, so is less likely to run out of guide stars in sertain situations.

The mono version is more sensitive than the color version, but also a bit more expensive. Tho, the couple times I used my color version for guiding back in march, I never ran out of guide stars so far.

If you have the Budget, then go for the mono Version. Otherwise go for the color Version. Both are fine cameras.

[ianpwilliams]

Ok thanks. I definitely need to look into this. It's not even a budget thing really (only £97 for an ST80), more because I imagine carrying the scope up and down stairs would be easier with a finder/guider. Just need to do more research into it.

Probably go for the mono camera too I think. Not sure about the accessories.

[laser_jock99]

Fair enough. Presumably you could use the the 80ED Pro as a guide scope though, and have the option of also imaging with that (although that could be a bit overkill).

If you had both scopes you have both options.

I have an ED80 sitting on top of my GSO 10" F4

Both scopes retail for similar prices (£350 vs £399) - but I'm using the 10" more often than 3" for imaging at the moment. I'm planning to do a head-to-head review on this pairing soon (need more clear skies....) to try and get some direct comparisons.

[ianpwilliams]

The budget is ever-increasing (due to the guide camera), so I'm keener on using a 9x50 as a finderscope/guidescope, or if not that then an ST80 as a guidescope.

Stupid beginner question here but...if I was using the finderscope as a guidescope, then I surely I wouldn't be able to use it as a guidescope if there was a camera in the back of it (unless I used it as a finderscope and then attached the camera)? But then I will have GOTO, so maybe I wouldn't really need a finderscope anyway? How does a finderscope/guidescope setup work in practice?

[RikM]

I use the older QHY5 mono camera on a 9x50mm finder using the adapter from Modern Astronomy. I have never yet failed to find a guide star with it over the past 2 years. The pro's are it's light and cheap and easy to mount. The Con's are if you allow the cables to drag, you will get some flexure because it isn't attached as securely as an ST80 bolted down hard to the tube rings. (Of course, if you allow the cables to drag, you will likely get flexure in the ST80 focuser anyway!). The finderguider is more suited to guiding shorter focal length instruments, where the extra FL of the ST80 could give you better control at longer FL's. Once you get much above a meter and a half, you will probably move to off-axis guiding anyway. I have used the finderguider to guide a 1200mm 250PX Newtonian and I found wind-shear more of a problem than guider focal length.

You are right, that with a camera attached, you can't use it as an optical finder. I use a Rigel QuikFinder to aid with my GoTo star alignment and then use the finderguider as a sort of electronic finder and center my alignment stars on screen. Same with centring my DSO target, I just take a 10sec sub through the finderguider and home in from there. (actually, I now just GoTo the target are, plate solve an image, sync the mount and then center the target astrometrically).

[Thalestris24]

Hi Rik

Um, "center the target astrometrically" ? Can you explain - not sure if it's what I think it is (being an Astrotortilla user )

Thanks

Louise

[ianpwilliams]

I'll be honest I didn't understand all of that. Are you working with a laptop? I was hoping to start without a laptop if possible (although it seems inevitable that I'll have to get one eventually).

[ianpwilliams]

I remembered Louse's suggestion from a while ago of buying a 75-300mm lens and taking some shots with that, and having seen some very impressive images taken with that, I'm considering starting out by imaging with that setup first, piggybacking it on the scope, in the hope that it might be a less steep learning curve. Presumably you would still need some kind of guiding setup anyway though...

I note that there is a 75-300mm and a 70-300 Canon lens, the second one being a lot more expensive:

http://www.amazon.co.uk/Canon-75-300mm-4-0-5-6-III-Lens/dp/B00005K47Y/ref=sr_1_1?ie=UTF8&qid=1399380410&sr=8-1&keywords=canon+300mm+lens

http://www.amazon.co.uk/Canon-70-300mm-4-0-5-6-USM-Lens/dp/B000B84KB6/ref=dp_ob_title_ce

Would imaging be possible with the first one?
 

[IanL]

I'll be honest I didn't understand all of that. Are you working with a laptop? I was hoping to start without a laptop if possible (although it seems inevitable that I'll have to get one eventually).

If you're using a DSLR you can start out with just the camera and no laptop, but to guide you'd need an autoguider (e.g. the Celestron NexGuide).  I've not used one but from what I've read they tend to be a bit 'hit and miss', i.e. if you are in focus and have a guidestar in view then you're good to go, but otherwise it can be a challenge to figure out what is wrong.

Conversely, to use a normal guide camera you will need a laptop and some guiding software to run it (e.g. PHD/PHD2, Metaguide or similar).  Cost-wise there are autoguiders and normal guide cameras in similar price brackets, but you have to add the cost of the laptop if using the latter.

Once you have the laptop, then using camera control software (BYE, APT, etc) to drive DSLR also makes it easier to see what is going on, plus you have focus tools and exposure plans, etc.  Plus you can control the mount via a planetarium, use plate solving software (e.g. AstroTortilla) to find your targets automatically, etc.  There is a heck of a lot to learn and it takes a few months to figure it out and get it working well, but in the end it is probably where you'll end up.

[Thalestris24]

I remembered Louse's suggestion from a while ago of buying a 75-300mm lens and taking some shots with that, and having seen some very impressive images taken with that, I'm considering starting out by imaging with that setup first, piggybacking it on the scope, in the hope that it might be a less steep learning curve. Presumably you would still need some kind of guiding setup anyway though...

I note that there is a 75-300mm and a 70-300 Canon lens, the second one being a lot more expensive:

http://www.amazon.co.uk/Canon-75-300mm-4-0-5-6-III-Lens/dp/B00005K47Y/ref=sr_1_1?ie=UTF8&qid=1399380410&sr=8-1&keywords=canon+300mm+lens

http://www.amazon.co.uk/Canon-70-300mm-4-0-5-6-USM-Lens/dp/B000B84KB6/ref=dp_ob_title_ce

Would imaging be possible with the first one?

Hi Ian

Yes indeed! Ideally being able to have a guide system is better than not. However, you can take multiple short exposures without and stack the results. IMHO, it's a good way to learn the basics It's how I started, anyway

If you can get your PA very accurate I expect you could do exposures of several mins at 300mm

Louise

[ianpwilliams]

Ok so guiding will be a necessity, and people don't recommend off-axis guiders, which means a guidecam, which means a laptop (or presumably a netbook). Can anyone recommend netbooks for astrophotography? I would do all my post-processing on my desktop, so presumably the netbook would only need to run the various software, so hopefully it wouldn't need to break the bank (like everything else!).

And yes it seems like the 75-300mm lens on the 1100D is the way to go to begin with. Hopefully I might be able to get a few decent images with the 1100D and without guiding to begin with, as it sounds like it's guiding that will open up the floodgates when it comes to cost and complexity.

[Thalestris24]

Ok so guiding will be a necessity, and people don't recommend off-axis guiders, which means a guidecam, which means a laptop (or presumably a netbook). Can anyone recommend netbooks for astrophotography? I would do all my post-processing on my desktop, so presumably the netbook would only need to run the various software, so hopefully it wouldn't need to break the bank (like everything else!).

And yes it seems like the 75-300mm lens on the 1100D is the way to go to begin with. Hopefully I might be able to get a few decent images with the 1100D and without guiding to begin with, as it sounds like it's guiding that will open up the floodgates when it comes to cost and complexity.

Hi

Yeah, AP is expensive! There are no two ways about it! However, it's up to you how far you take it. Fwiw, I should mention that for not much more than the cost of a 75-300mm canon lens you can buy a 400mm F5 ST80 + dovetail+ Celestron T-adapter. You then just need a canon t-ring to be able to attach a canon to the ST-80. I believe some people just use the on-camera liveview for focusing and a cheap intervalometer to take multiple exposures with. As long as you keep to short exposures you can get away without guiding so don't need a laptop for that. It's a start - you don't have to go all the way at once.

Louise

[ianpwilliams]

Yeah I need to do this a bit at a time. My shopping list including imaging is currently standing at £2100 which is frankly terrifying...

[PeterCPC]

Yeah I need to do this a bit at a time. My shopping list including imaging is currently standing at £2100 which is frankly terrifying...

It only get's worse believe me!

Peter

[RikM]

Hi Rik

Um, "center the target astrometrically" ? Can you explain - not sure if it's what I think it is (being an Astrotortilla user )

Thanks

Louise

I use Pinpoint rather than Astrotortilla but I imagine it works the same way. GoTo the target and it will probably be somewhere handy. Take an image, solve it to find the image centre, sync the GoTo to the image centre so the scope knows exactly where it is pointing and then tell it to GoTo the target again.

[Thalestris24]

I use Pinpoint rather than Astrotortilla but I imagine it works the same way. GoTo the target and it will probably be somewhere handy. Take an image, solve it to find the image centre, sync the GoTo to the image centre so the scope knows exactly where it is pointing and then tell it to GoTo the target again.

Hi Rik

Ok - never heard of 'Pinpoint' - I'll Google it when I get a min. Yeah AT will do the same and can automatically re-slew until within a given tolerance though that's not really necessary.

Cheers

Louise

[ianpwilliams]

Hi

Yeah, AP is expensive! There are no two ways about it! However, it's up to you how far you take it. Fwiw, I should mention that for not much more than the cost of a 75-300mm canon lens you can buy a 400mm F5 ST80 + dovetail+ Celestron T-adapter. You then just need a canon t-ring to be able to attach a canon to the ST-80. I believe some people just use the on-camera liveview for focusing and a cheap intervalometer to take multiple exposures with. As long as you keep to short exposures you can get away without guiding so don't need a laptop for that. It's a start - you don't have to go all the way at once.

Louise

That sounds like it could be a better idea, what with the 300mm lens costing the same as the ST80, and seeing as I would need an ST80 later anyway for guiding.

But then if I'm not guiding anyway to begin with, and stacking short subs, then couldn't I just connect the Canon to the 150PDS rather than the ST80, as I would once I had a guiding setup? Or does taking usable unguided subs become more difficult when you go from 300mm to ST80 to 150PDS?

[ianpwilliams]

Although I suppose if the 1100D was connected to the ST80 rather than the 150PDS, then at least I could do some visual through the 150PDS in between imaging through the ST80.

[RikM]

The longer the focal length, the quicker any tracking or polar alignment error shows up. Without guiding, using a 150P on an EQ3-2 I could routinely get 60 - 90sec exposures, some images in my gallery. With just a DSLR on the mount I could do 3mins with either 50mm or 300mm lenses. I find it much easier to use the 150P than camera lenses because if the ease of focusing. I would expect a decent 300mm lens to be better than an ST80 for DSLR use?

[ianpwilliams]

Interesting. I'm getting an HEQ5 Pro, so I'm hopeful that I could get some quite long subs unguided with that. So it sounds like I could get the Canon camera and image unguided through the 150 for now, and get the ST80 later on for guided 150 imaging.

And maybe I could get the 300mm lens anyway for wider FOV shots. Although if I was going to pay £100 for ST80 and £100 for 300mm, then I might as well pay £300 (or maybe £200 preowned) for an ED80 Pro instead, because I know I couldn't image through the ST80.

[Thalestris24]

Interesting. I'm getting an HEQ5 Pro, so I'm hopeful that I could get some quite long subs unguided with that. So it sounds like I could get the Canon camera and image unguided through the 150 for now, and get the ST80 later on for guided 150 imaging.

And maybe I could get the 300mm lens anyway for wider FOV shots. Although if I was going to pay £100 for ST80 and £100 for 300mm, then I might as well pay £300 (or maybe £200 preowned) for an ED80 Pro instead, because I know I couldn't image through the ST80.

Hi

You could do that! If you want to do imaging you obviously have to start somewhere! It's up to you! There is a lot to learn and it will take time. You could just get the mount, main scope and camera + t-ring. That seems to be the cheapest starting point. I wouldn't like to guarantee how long your subs might be without star elongation setting in but you will be able to get images and can learn how to set the scope up, polar align, focus, find targets, take images, process them etc.

Good luck!

Louise

[ianpwilliams]

Thanks, I definitely think this is way to go for me. It's a good excuse to just buy a couple of things rather than diving in at the deep end, and like you say I'm sure it will be a good way to learn the basics too.

[wxsatuser]

Yeah I need to do this a bit at a time. My shopping list including imaging is currently standing at £2100 which is frankly terrifying...

and you have only just started.

and to think most of the time clouds stop you using it..