taking long exposures with heavy light polloution

[Thalestris24]

ps before spending any money on anything it's recommended that you read and understand about dso astrophotography e.g. http://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html

[oldpink]

couldn't agree more, you can't beat dark skies
the difference is incredible here I can hardly see Orions belt, 50 miles away I can see the whole Milky way

I just need to get away when there is clear skies

[ianpwilliams]

ps before spending any money on anything it's recommended that you read and understand about dso astrophotography e.g. http://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html

I will definitely be buying that book, although I was planning on buying a scope and learning how to do visual, and then buying that book once I've got a better idea of what I'm doing. For starting out I need something basic, like Stargazing for Dummies, which is a proper step-by-step book (I now know what polar alignment is!). I did get Turn Left at Orion from the library, which is great, but the majority of it does seem to be about locating objects rather than literally starting out.

And as for dark skies, unfortunately it just won't be an option for me (I doubt I'll ever be able to avoid a car), so I will have to learn to do the best I can with light pollution. And it sounds like what scope and mount I buy won't affect things when it comes to light pollution, and that it will be more about what filter I buy (I think it will be worth investing in a high-quality one), and what processing software I use afterwards.

Having said that, I'm confident that my dad will be interested in coming over in his car every now and then, maybe with the odd trip to Wales, and I'm also planning on asking the members at my local astronomy society if any of them are Liverpool-based and might be interested in car-sharing any time. So hopefully it won't ALWAYS have to just be light pollution and nothing else.

[ianpwilliams]

That should be "afford a car", not "avoid a car". Makes me sound like I keep getting run over

[RikM]

I will definitely be buying that book, although I was planning on buying a scope and learning how to do visual, and then buying that book once I've got a better idea of what I'm doing. 

You have that round the wrong way. The point of buying the book is so you have a better idea of what you are doing, so you can buy the right telescope for what you want to do.

Visual astronomy and imaging have totally different equipment requirements.

[ianpwilliams]

I've done a lot of research and asked a lot of questions on these forums, and I believe that it is possible to do both on one scope, it's just that there will always be a bias one way or the other. For example I was looking at a Skywatcher 150/200PDS and an EQ5/HEQ5 mount (I'm aware that the weight load needs to be as small as possible), and I'm sure I could do both with that kind of setup (with motors, a camera, and a laptop). I know there are scopes like Dobs which are purely for visual, and scopes like the ED80 for imaging, but I'm not convinced that I would need two scopes, not based on some of the Skywatcher 130/150/200 images I've seen on these forums.

[RikM]

I agree it is quite possible to do both with one scope but not necessarily optimal. A small refractor on a big equatorial mount is optimal for imaging and is comfortable to use for observing, but not very satisfying if you like faint fuzzies. A big Newtonian on a Dobsonian mount is optimal for observing but  on a big EQ is a right royal pain to use visually. The compromise is, as you say, a mid-size Newtonian on a mid-size EQ mount. Just so long as you realise it is an appetizer to give you a taste of both and then you will need/want to upgrade later, whichever path you choose.

It is also the exact path I went down. I started with a compromise scope (150P on a driven EQ3-2) then after 18months, decided what I wanted to do... both so saved for a bigger EQ mount for imaging and a bigger Newt on a Dob mount for observing. It is possible, and extremely rewarding to do both with one set-up if you are up for it. It isn't easy.

[ianpwilliams]

Yeah I was considering one of two setups where the weight would be kept relatively low e.g. a 150 on an EQ5 or a 200 on an HEQ5 (although £1k is a scary investment!). And it does sound like it could be worth getting a separate Dob for visual, due to their ease of use and value for money.

I'm looking forward to getting down to my local astronomical society and hopefully seeing some scopes in action.

[Russe]

Yeah I was considering one of two setups where the weight would be kept relatively low e.g. a 150 on an EQ5 or a 200 on an HEQ5 (although £1k is a scary investment!). And it does sound like it could be worth getting a separate Dob for visual, due to their ease of use and value for money.

I'm looking forward to getting down to my local astronomical society and hopefully seeing some scopes in action.

TBH - I think the 200 on a HEQ5 will be a bit much of a muchness. When you think long exposures, think guiding. That'll put extra weight on it. The 150pds is quite a windsail already and aperture isn't really a big issue in DSO AP. Much more the f/ratio. If you go for 5min + exposures the slightest nudge will mess up your subs...

[ianpwilliams]

I'd like to go for the 200PDS on the HEQ5 Pro, because I know the PDS is smaller and lighter than the P, and although the imaging would be the same as with the 150 because of the focal ratio, the 200 would presumably also give better views than a 150. Although I don't know by how much, because I can't get anywhere to see any in action. If the visual difference was negligible then I would consider a 150PDS instead.

And I've seen some great DSO images on this forum using 150's on EQ3-2's and 200's on EQ5's, so I'm convinced that a 200 on an HEQ5 Pro should be fine, because it's it's much stronger mount than the default one, i.e. the 200P on the EQ5, which is originally what I was looking at.

I would no doubt be happy to split it later, maybe go for an ED80 on the HEQ5 for imaging, and a nice big Dob for visual, but to begin with I can only afford one scope and mount, and so I need to be able to do a bit of both.

[bruno]

these are two shots what i took the other night as you can see the light pollution is pretty bad  i stacked about 7 of these with no darks bais  the final picture came out whitei then adjusted the setting in DSS to bring the picture back then put it in Ps and tweaked the curves & levels twice looks a lot better i think

[Russe]

The 200pds on the HEQ5 will be fine unless you use a guiding setup. In several threads on this forum you will find people who complain that the 200pds moves with the slightest winds. If you don't live in the UK, that might not be an issue for you. Otherwise, I'd think about it.

[oldpink]

my 200 is useless in anything over 10mph winds
the shake kills any decent exposures

[ianpwilliams]

Well I was planning on using the GOTO on the SynScan for guiding, and then maybe using a laptop later. So it sounds like it's not worth going above a 150 then? I would rather go with a PDS than P anyway, because it's better for imaging, and many people say it's just as good for visual as the 150P is. Unless the 150P and 200P are better than the 150PDS and 200PDS because they provide a better balance or something.

[Russe]

As far as I've READ - for a 200pds you'll need a very sturdy mount - somewhere along NEQ6. Which is quite a heavy beast (I find my HEQ5 borderline). The visual difference between a 130pds and a 200pds should be quite impressive (I have not seen it). Then, I stopped visual astro b/o our light pollution.

The difference between 150&130pds:

visually they're about the same. For AP exposure lengths, there's no difference.

FOV: 130pds s-l-i-g-h-t-l-y bigger.

Weight: 130pds lighter. 150pds starting to be windsail on HEQ5.

Balance: more difficult with 130pds b/o short tube length, if you have a dew shield, finder guider setup and heavy camera (my 450D is about the lightest Canon, and I can just about achieve balance with everything on).

Focuser: very good stock focuser on both. 130pds currently not upgradable to moonlite. Focuser tube protruding into scope tube on 130pds when focusing with DSLR (probably same with CCD).

In essence - you'll probably need more than 1 scope...

Just as a thought - there are people starting out with a Mak - excellent for moon / planets and for starting out with AP and the whole rest of it.

Once you learn guiding, and you have a smoothly running setup, you could try guiding with a long focal length for nice close ups of galaxies. (Don't do this though without having done DSO's with a fast scope - it's REALLY NOT EASY).

Sorry not to be able to give you the ultimate answer...

[Russe]

The GOTO on a SynScan for "tracking" - not "guiding".

Or did I misunderstand something? Because I'm using the synscan in PC direct mode to connect to my laptop, where I've got a second camera connected to a finder scope for guiding.

Makes sense???

Liverpool is a bit far away, would have liked to show you what I mean...

[lensman57]

I will definitely be buying that book, although I was planning on buying a scope and learning how to do visual, and then buying that book once I've got a better idea of what I'm doing. For starting out I need something basic, like Stargazing for Dummies, which is a proper step-by-step book (I now know what polar alignment is!). I did get Turn Left at Orion from the library, which is great, but the majority of it does seem to be about locating objects rather than literally starting out.

And as for dark skies, unfortunately it just won't be an option for me (I doubt I'll ever be able to avoid a car), so I will have to learn to do the best I can with light pollution. And it sounds like what scope and mount I buy won't affect things when it comes to light pollution, and that it will be more about what filter I buy (I think it will be worth investing in a high-quality one), and what processing software I use afterwards.

Having said that, I'm confident that my dad will be interested in coming over in his car every now and then, maybe with the odd trip to Wales, and I'm also planning on asking the members at my local astronomy society if any of them are Liverpool-based and might be interested in car-sharing any time. So hopefully it won't ALWAYS have to just be light pollution and nothing else.

The combination of the scope, mount, and the imaging camera that you'd need depends to a great extent on the type of targets that you wish to observe or image. There is no such thing as a  universal imaging scope or camera, that is why we all end up with a number  of scopess, cameras  and even mounts . The book in discussion will  give you something to think about before a purchase but it will not tell you what to buy, that is your decision entirely. A planetary scope is a different beast to a widefield DSO scope or a fast long system for going deep into space with corresponding demand on the type of the camera and mount. A NEWT is the best value for money scope per inch of aperture and as a whole they are quite fast but they also have inherent weaknesses that may prove too much for an inexperinced user and before you make a decision you should be aware of this. You have a lot to think about before forking out for a scope and mount.

Regards,

A.G

[Mr TamiyaCowboy]

take one of your orange glow subs, make a copy. 

now IMPORT that copy into G.I.M.P.

now heres the cheap mans way to do it.

Click Colors

Click Levels. 

new box opens with a histogram and some sliders.

note how your histogram is all bunched to the right hand side.

TAKE the left black slider and move this to the right where your

histogram starts to appear.

Now take the middle slider and move this MID way between the black and white slider

to the left and right of it. 

now as you adjust this gray slider you may need to tweek the white, but it should not need touching.

you should see that your image background is now a darker color, your stars are bright but not blown out.

and the shifting of the gray slider allows image to pop out with contrast.

once you have that single sub looking like you want, save the levels profile,

and run the whole sub set through in batch mode using the preset level profile you made.

YOU WILL loose some data, but for newcomers its a quick and simple way to remove light pollution.

and still keep enough data to get something from the images.

the first image : this was taken in the sahara dust glow in norfolk , England.

its a 20s capture at ISO1600 on a 50mm camera lens.

Second Image : Shows the same photograph but all that has been done is the above method.

[ianpwilliams]

The problem is that I've been thinking about it for a very long time now. I've been very patient, and kept on researching and asking questions, but with it being a forum I obviously get different views and opinions, and therefore different answers. And I do wonder if the Photon book would contain conflicting information too.

Basically I'm very restricted. I'm in a second-floor flat, so portability is important (which means GOTO rather than a laptop, certainly to begin with). I have no car, so I'm restricted to the back yard, which means that some parts of the sky are blocked either by my house or by trees, so it wouldn't be a case of choosing what to observe or image, rather being dictated to. And I have light pollution to deal with.

My main interest is DSO photography, but I don't want to go for a tiny aperture like the ED80 or something, because it would be nice to be able to see SOMETHING as well, rather than just go outside do some imaging, and come back in, and never actually look.

This thread confuses me, because there are some excellent images on there taken with a 150P on an EQ3-2 with dual axis drives, and with a 150P on an HEQ5 mount, but then people say that it's realistic because they are too big and would catch the wind.

I did visit my local astronomical society, but there wasn't much going on that night, so I didn't have the opportunity to see any scopes, or the views they produced.

So eventually it seems you get to a point where you have to just buy something and hope for the best. Unless that Photon book can tell me exactly what I should be going for based on my circumstances and preferences.

[Russe]

The problem is that I've been thinking about it for a very long time now. I've been very patient, and kept on researching and asking questions, but with it being a forum I obviously get different views and opinions, and therefore different answers. And I do wonder if the Photon book would contain conflicting information too.

Basically I'm very restricted. I'm in a second-floor flat, so portability is important (which means GOTO rather than a laptop, certainly to begin with). I have no car, so I'm restricted to the back yard, which means that some parts of the sky are blocked either by my house or by trees, so it wouldn't be a case of choosing what to observe or image, rather being dictated to. And I have light pollution to deal with.

My main interest is DSO photography, but I don't want to go for a tiny aperture like the ED80 or something, because it would be nice to be able to see SOMETHING as well, rather than just go outside do some imaging, and come back in, and never actually look.

This thread confuses me, because there are some excellent images on there taken with a 150P on an EQ3-2 with dual axis drives, and with a 150P on an HEQ5 mount, but then people say that it's realistic because they are too big and would catch the wind.

I did visit my local astronomical society, but there wasn't much going on that night, so I didn't have the opportunity to see any scopes, or the views they produced.

So eventually it seems you get to a point where you have to just buy something and hope for the best. Unless that Photon book can tell me exactly what I should be going for based on my circumstances and preferences.

Sorry! You certainly have scratched your brain for a while. And yes, you will have to buy smth and hope for the best. I think, if you say goodbye to thinking - one scope for all - you'll be fine.

A 200pds is a lovely scope - and should you at some point realise, that the mount you have is not quite stable enough for your 35 hrs exposures (joke) - then you can easily upgrade. In particular, if you start out with a mount that people are keen to have.

I would go for and EQ mount - they will usually sell at a good price, in particular if you have and EQ5 or even HEQ5. The 200pds will most certainly give you lovely views, much better than a smaller aperture!

I think, you are right - keeping in mind what you've heard - you are not making a mistake with a 200pds on an HEQ5. You get a GOTO feature as well - which is for most people a nice thing to have initially.

For DSO photography, that will last several hours etc etc - you will go for a laptop connection at one point. But most certainly you can start taking some lovely little images, that are all YOUR OWN with this great setup.

I'm sorry if so many opinions are confusing - they are indeed. At least you are not making the mistake I did - buy without knowing what you should go for...

Good luck in your endeavours!!

[oldpink]

Every proton counts is a very good book that explains a lot and gives you a great insight into this hobby

as most people say the mount is important Esp in AP
the better your mount the more stable it will be and allow for longer exposures

my 200 on the EQ5 is pushing the limits of the mount and adding a guiding setup will most likely overload it
so I will be upgrading later this year but I expected this was going to be the case but for now I will plod on with the EQ5 and its limitations

[Thalestris24]

Hi Ian

Yes, it _is_ confusing, I know. At the end of the day, you don't know how things will be until you actually do it! You could go along to a local astronomy society and talk to people who have had experience of various setups and could show you and advise you. I'm sure there must be one in Liverpool. Like you, I live in a 2nd floor flat close to Glasgow city centre. So I have similar problems with light pollution and also not having a car, with mobility. I've chosen to do my AP through an open window. It's very restricting and challenging but I don't have to worry about wind! As you can see from my sig I have a 150pds on an Heq5 Syntrek. This is fine. I originally had the idea of taking everything outside to do my AP but that's not easy either. The Heq5 is quite heavy (for little me!) and to cart everything downstairs only to find it had clouded over by the time I might have got everything set up is off-putting, to say the least! Plus I don't have a laptop or a portable power source. So, for now, at least, I've decided to stay in. This has allowed me to learn a lot without exhausting myself. From a practical point of view, imaging and observing are two different things and requires two different scopes. Once you are set up with a camera fixed to your scope, you don't want to be taking it off and putting it back on - just not feasible, I don't think. I've no experience of observing but I know that many DSO objects aren't clearly visible to the eye - they are just too faint and need long exposures by a sensitive camera to pick them up.

Hope that helps

Louise

[ianpwilliams]

Thanks for that. Seems we are in a similar situation.

I did myself consider trying it out of a window at one point. I know that people don't recommend that, mainly because the heat escaping through the window can distort the view etc. As it happens, in my case that probably wouldn't have been an issue, because I don't keep my bedroom heated. But it wouldn't work anyway, just because of the way the window opens.

And yes I'm aware that the HEQ5's are heavy (24kg?!?), I'm fairly strong, but I would struggle with that too. I was planning on keeping that on the ground floor, so I would only have to carry the scope etc up and down the stairs, which would be fine. And I would go with the SynScan to avoid adding a laptop to that carrying (although I'm sure I'd give in a and buy one eventually).

And when it comes to imaging and visual, I was thinking about going down the route of DSO photography, and then maybe a bit of visual of the moon and planets. I'm aware that a camera can see a lot more than the human eye (in colour too), and like you say, I wouldn't be able to see much DSO-wise visually anyway, but I'm sure I could get reasonable views of the planets (and certainly the moon) with a 150 or 200. So the idea was that I would do visual sessions or imaging sessions, or possibly the odd split session of imaging first then visual, or vice-versa, rather than constantly changing and having to take the camera on and off.

And when it comes to the mount, I'm really quite keen to go for a second-hand HEQ5 Pro, because one of those with a new 150PDS or similar wouldn't costs all that much more than a new 200P EQ5 for instance. And I know I would be very happy with an HEQ5 whatever I wanted to do. The only annoying thing is they sell so damn fast because they are so popular! I made an offer for one the other day, the day after it was listed, and I was still too late!

[ianpwilliams]

Some great images there by the way Brown Dwarf!

[Thalestris24]

Thanks for that. Seems we are in a similar situation.

 

I did myself consider trying it out of a window at one point. I know that people don't recommend that, mainly because the heat escaping through the window can distort the view etc. As it happens, in my case that probably wouldn't have been an issue, because I don't keep my bedroom heated. But it wouldn't work anyway, just because of the way the window opens.

 

And yes I'm aware that the HEQ5's are heavy (24kg?!?), I'm fairly strong, but I would struggle with that too. I was planning on keeping that on the ground floor, so I would only have to carry the scope etc up and down the stairs, which would be fine. And I would go with the SynScan to avoid adding a laptop to that carrying (although I'm sure I'd give in a and buy one eventually).

 

And when it comes to imaging and visual, I was thinking about going down the route of DSO photography, and then maybe a bit of visual of the moon and planets. I'm aware that a camera can see a lot more than the human eye (in colour too), and like you say, I wouldn't be able to see much DSO-wise visually anyway, but I'm sure I could get reasonable views of the planets (and certainly the moon) with a 150 or 200. So the idea was that I would do visual sessions or imaging sessions, or possibly the odd split session of imaging first then visual, or vice-versa, rather than constantly changing and having to take the camera on and off.

 

And when it comes to the mount, I'm really quite keen to go for a second-hand HEQ5 Pro, because one of those with a new 150PDS or similar wouldn't costs all that much more than a new 200P EQ5 for instance. And I know I would be very happy with an HEQ5 whatever I wanted to do. The only annoying thing is they sell so damn fast because they are so popular! I made an offer for one the other day, the day after it was listed, and I was still too late!

Yeah, I'm lucky I have a window I can use . An Heq5 is a good all-rounder and quite sturdy - certainly ok with a 150pds. With a 200pds it may be less than optimal but I can only make that comment from what I've read and been advised myself. Both have a focal ratio of F5 - good for imaging. The 150pds has a focal length of 750mm, also good for most things. Maybe ok for planetary visuals with a barlow - I'm not sure. My system is set up on a semi-permanent basis. I don't remove the camera unless I really need to. From an imaging point of view you need to take 'flats' which are highly dependent on the optical train not changing from when you've taken 'lights'. If you start taking off the camera then this can cause problems. You also need to keep whatever camera you use clean and dust free, so removing during a session and in the dark might be potentially hazardous. You probably can do short exposures without a laptop though things like focusing and monitoring exposures would be that much harder, I imagine. Remember, Synscan is just used for goto's - it doesn't make your mount track accurately for imaging. You need accurate polar alignment and a guiding setup for anything more than maybe 60s subs. 60s is no time at all for DSOs where integration time is often measured in hours. You will also need a good portable power tank/battery with adequate Ah.

It's often said that the best telescope is the one you use - something to bear in mind. I started off with the HEQ5 syntrek and a Canon 1100d + 75-300mm lens. Learnt a lot with just those! It was also a simple and easy setup to use. The longer the focal length, the harder to track and guide. It's all quite easy with a 300mm lens! So you don't even need a scope to start off in imaging! Imaging is a steep learning curve - not just taking the images but the processing too. A glance around the forums will highlight the most common sorts of problems and frustrations imagers suffer. If only the British weather was more conducive!

Regards

Louise