simmo39

Thanks, hope you are right.

Thanks Alan. I will give that ago.

Hi Vlaiv. Thanks for the pointers. I will have to sit and digest all you have said and see if I can do it. The M 51 image is not one of my favourites and I'm was only shooting it to pass time till the nebula return. I'm just hoping that by then I will have sorted these problems. Once again thank you for the hints.

Hi Alan. Yes I'm a Pi user, I have used all of the above and for the most part removed them from the final image. Where I shoot from is not to bad for light poullution at the moment as the main Street light that causes me problems is out of action. I was wondering if it was light pollution but I didn't get it on my first RGB image and nothing has really changed between the two images. Thanks Andy.

Thanks Knobby, think you are being very kind. No its not and you are right, when it does all come together its brilliant!

After getting data and finding not the best Im always loathed just to dump it! so here is a poor go at M51. The main problem is in this thread: Any help on ideas why its there would be helpfull. Any way to the main show. LRGB M 51 30 x 120s for RGB and 58 x 120 L. Taken with ASI 1600 mm through my out of collimation SW 120 PDS ( Thats another problem! ) Not one of my best but at leastI pulled something out of the bag. Cant wait till the new season starts as Im not really a galaxy man. Thanks for looking.

Hi Craney, I had 30 subs of green. I would have thought that the stacking would have got rid of it.

Hi, first off sorry if I have posted this in the wrong place and feel free to move it. Anyway I have been doing a bit of RGB imaging on M 51, this is only my second attempt at rgb and usually do narrow band. Below is a first stretch of the combined data and although I can get rid of most of the green blocks I just wondering what is causing them. Is it frost, internal reflections or something else? I have manged to get rid of the worst of it on some of my images of M51 and the green didnt show on my first RGB target. Any tips pointers or answers welcome.

V nice!

Thanks, Im at 65.5mm I think I need to go back a little to get it at its best. Im really impressed by the scope and the TS FR/FF seems to work very well with my camera set up.

Hi, managed to get a single Ha frame in last night just to test spacing. The spacing is still a little off but here is a 240s sub tweaked a little i PI. Think Im going to like this scope!

Thank you, That does help. Now if you can calculate the clouds away that would be brilliant!

So what is your average RGB sub lenght, L is 15s that seems v short. I think with number crunched by my poor head 60s for L but that could be off as I guessing the bits I dont understand ! lol. At least I have got a starting point all I need now is the weather to cooperate.

BTW, I think the SQM value here is: 20.4–21.3

Hope it works, I use APT and im not sure if it works the same.

from the numbers i would say my light pollution is average. I have no idea about SQM sorry.

Hi Vlaiv. Thanks for the reply. I'm going to be using my new SW 72ED. Think it's about F5. Comparing to my SW 130 PDS is F4.8 I think. I have been using 240s subs for narrow band with that and was hoping that 240s for NB would be good for the 72ED. As for the RGB I was thinking about 120s, do you think that would be a good starting point or should I see if I can push it to 240s?

Hi, thanks for the pointers. I think my light pollution is classed Bortle 4 - 5. I will have a look at the CN site, once again thank you.

Hi all, I know this has been asked before but i cant seem to find the answer. I have been doing Narrow band since I got the camera but with galaxy season coming I treated myself to some RGB and L filters. I have set my gain to 200 for the NB but will go back to unity gain for RGB. Im just wondering where to start my subs at, I thought about 120s for the RGB but what about the L? is that the same and also what kind of ratio am i looking at between RGB and L? Thanks in advance.

Hi all, I braved the winds last night just to see if I can get focus with my 72 ed using the TS ff/ reducer with my ASI 1600mm and im glad to say I did with no problems. I have still got to get the spacing right but from the single shot I took last night it all seems do able. There was plenty of Focus tube left! thank you all those who pointed me in the right direction. cant wait to use this scope in anger!

Thats it, no good weather for at least a month then! lol. good luck hope it all works out well.

Well, Got my 72 ED this week, Also went for TS FF/fr. I have had a quick set up pay in the house but as usual the weather not letting me test it. Also for those interested the SW auto focuser fits no problem. I have set the spacing for the FR to 65mm for the first test, does that sound about right? Im using a ZWO 1600 mm pro and narrow band filters for this set up so wish me luck!

Oh well, I'll be looking at the TS one more expense! Hope you get sorted.

Hi, well I hope you can get it sorted. weather is going to be a pain for the next few weeks. think ill be going for TS one if you dont have any luck. All the best. Andy

Any news on this FF/ fr ? Just waiting to see which one to go for.