Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep28_banner.thumb.jpg.b94278254f44dd38f3f7ee896fe45525.jpg

Max Scrotes

Imaging Equipment and Light Pollution

Recommended Posts

Hello,

Quick introduction, i have been interested in astronomy for a long time. I have a pair of 25x100 bino's and an old 125 etx with a knackered mount. As i do not drive and live on the edge of London, light pollution has always been a serious problem for me but after getting the bug again ( and quitting smoking so i have actually some money to spend ) and the results from video astronomy, there may be hope for me yet.

is this really a viable alternative for me being stuck in a red zone ?  after doing some research i am leaning towards an evolution 8 or 925 and a zwo 224 camera. i know the limitations of the camera on dso's and the telescopes fov but i would like to try it on a few dso targets if possible. But i will mainly like to image the moon and planets to start off with, perhaps getting a dedicated dso camera a few years down the line. 

so, the actual question is, from a heavy light polluted area will i get satisfying results ?  or am i doomed forever. if not, should i get a certain filter to help cut through the ominous glow of the A road lights 1/2 a mile away ?  if this is viable would it be better for me to de-fork the etx for use on the mount and just get the evolution mount and a wider field telescope ? any other equipment recommendations ? 

Here are a couple of images from my location ( 4 am ), any comments or advice would be greatly appreciated, thank you.

P1040345.thumb.JPG.2b7b0ff9ab56e8deaaca00acb4ef3897.JPGP1040346.thumb.JPG.af3bb5f660f4d051181d72f465e3b53f.JPG

Share this post


Link to post
Share on other sites

Narrowband is the way to go if you have LP.

I'm in a small town but we have loads of LP from new streetlights, a footie club and a school/leisure centre.
Nights are really bright here but narrowband beats it fairly easily.
Here are two I did earlier this week, first one with most lights on second half subs with lights out.

sadr.jpg

heartsoul.jpg

and here is the front of our property, there are 8 lights within a hundred yards, to left are 6 football club lighting towers, these are on every night.
Also to the left is a school that has lights on all night and behind that a leisure centre with courts lit up most of the night.

streetlights.thumb.jpg.d3ca5862650121923a48279998cfc357.jpg

Edited by wxsatuser
  • Like 8

Share this post


Link to post
Share on other sites

Good that you stopped smoking.. that will also improve your dark adaptation/sensitivity...

The 8" Scope will be great for solar system imaging and light pollution will not affect planets or the moon since they are already very bright.

When it comes to deep space objects, as mentioned above, narowband will help you cut out the LP, but you can also limit the sub exposures to a level where the LP wont over expose the frame and stack multiple subs when imaging in RGB or OSC.

Regarding field of view, you can add a focal reducer to increase the FOV but I have been imaging at 2000mm and there are a lot of objects where the 8" at 1280mm (with a focal reducer) or 2000mm is a great focal length... of course 2000mm needs good tracking to get decent quality, so a Alt-az mount will not do for DSO, and you will need to put the scope on either a Equatorial mount or add a wedge to you EVO Alt-Az mount.

  • Like 1

Share this post


Link to post
Share on other sites

You should check out SGL member Nytecam's (Maurice Gavin) website http://home.freeuk.com/m.gavin/cnlinks.html Instead of targeting the widefield objects better suited to darker skies Maurice uses a longer focal length 12" SCT and sensitive Lodestar cameras to target smaller objects like galaxies, planetary neb... Instead of targeting the widefield objects better suited to darker skies.

Edited by laser_jock99
  • Like 1

Share this post


Link to post
Share on other sites

Thank you for replying guys. Wow that is really bad light pollution, amazing what you can achieve with nb filters :D  Some food for thought to ponder over. I was thinking of video astronomy with short subs and stacking, then look into 'serious'  imaging a few years down the line when i have gained more experience with the hardware and software. that way i can use the evo mount as a portable platform when i do get an eq mount and all the goodies i need to go with it.

Again, thank you for all the advice.

Share this post


Link to post
Share on other sites

Best advice is try. It's easy to assume LP affects all you can do, but it can be really directional.

I am surrounded by appalling LP on two sides and a dual carriage way on the third. I can't see anything other than really bright stars like Capella low down to the northeast but on a clear night I can see the Milky way when its directly overhead, so imaging is fine as long as I don't go too low. I do have to make use of gradient removal tools though.

Share this post


Link to post
Share on other sites

A 8 inch or 9.25 with a asi224 is a brilliant combo for the planets and moon...and can still get decent results from fairly light polluted skies.. not sure on the asi224 on dso thou..

If you wish to do dso in your type of location then yeah I'd suggest ha narrowband is the only real solution..on the plus side using s small frac makes them fairly portable if you wish to go to dark sky locations..

Share this post


Link to post
Share on other sites

I image from a Bortle white zone. There really is nothing that you can't image well,  but you will need far longer total exposure time ( i.e. Shorter but many more subs) and some special processing skills and plugins to do it right. Every image on my website is from bright skies.

http://www.pbase.com/dsantiago/root

 

Derek

 

 

Share this post


Link to post
Share on other sites

Wish i have more complete tools then i will start to imaging and show you, i also live in a light polluted area, red zone which is closer to white zone not much far from my house, but i can assure you that i was able to see some stars that are part of nice DSO, M45 and M42, what else i need then, hehehehe

Share this post


Link to post
Share on other sites

Sounds like you are in a similar situation to me, I can't see anything much -- except if you use a camera. Which got me into EEA.

I'm in zone 2 central London and can get satisfactory views with short sub stacking (usually under 10 seconds) on an ASI290 mono to see galaxies clusters and nebula. Its not going to compete with Hubble any time soon, so if you have realistic expectations you should have fun. The 224 and the 290 are the best ZWO cameras for smaller dso objects at the moment and they work well with sharpcap live stacking. You need sensitive, low noise cameras and a fast scope. Those cameras fit the bill. 290 is best for mono 224 for colour. They both work for dso viewing. If you're only looking at short subs for EEA you can even go with the uncooled versions to save money.

Check out the EEA forums for more info and post questions there too. Also on cloudy nights -- some people are on both forums. Particularly look for HiloDon, AstroJedi's and Martin Meredith's posts. They have a lot of good information and examples of what to do and buy. AstroJedi is particularly technical and very much praises the ASI290 and asi224. You can find examples on his YouTube channel of the results and how fast images come in, he lives in San Diego with bad light pollution too. He managed to image the relativistic jet in Virgo A which is pretty good going.

I think a 224 and an evo 8 would be a great combo -- but for EEA you will want to speed up the scope -- rule of thumb is f/5 or under. That allows you to have shorter subs. You can get a hyperstar for the Evo that will make it a stunning f/2. It's not cheap but makes it pretty impressive. I currently use a skywatcher 150pds at f/5. Alas, I didn't have space for an 8" in my flat. 

You should also check out what your fov is going to be with each camera / scope combo using the astronomy tools website. 

The best thing is to read around the EEA / video astronomy forums, see what people use and ask some more questions!

Edited by London_David

Share this post


Link to post
Share on other sites

Thank you for easing my concerns. I was more worried that i would see no dso's at all from my location. I have been scanning these forums and cloudy nights for the last few weeks to try and get up to speed on new technology and what is possible from a light polluted area these days. I have some experience in photoshop and quite tech savvy, small dso's with an 0.5 focal reducer is my plan and perhaps hyperstar/narrowband down the line.

 

i just want to keep it simple for now and practice on the moon/planets and a few smaller, brighter dso's  :)

 

thank you again for all your input guys.

Share this post


Link to post
Share on other sites

I've found that bad weather and seeing have been a bigger issue for me in terms of the actual experience. Light pollution is obviously a seriousl limit to what you can see but you don't really think about it when you are at the scope. There's still plenty to see and explore.

How limited you are only really hits you when you switch out to a visual eyepiece or look through your finder and see nothing. Also, when hunting for dso's, sometimes it can be be hard to find a target because there is nothing to see except through the camera -- and even then only after stacking. But in some ways part of the fun is trying to get good results in a difficult location.

Edited by London_David
  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.