Art Gecko

On my 130p I cut 15mm off the back of the tube and remounted the mirror to bring the camera to focus... a 2x Barlow will do the job but makes the image more unsteady and you need to increase open shutter time by something like 4x to gather the same amount of light

I think I vaguely remember focussing mine Before screwing it into the mount... but I may be wrong I don’t know for sure if that makes a difference

Does a polar scope have focus adjusters? I can’t remember!! Been so long since I had to calibrate one!!

You should be able to see the markings in daylight... you need to!! Otherwise how have you calibrated/centred it to the mount?? Where did you get it?

I used to strap a head torch with a red light to mine and angle it so the markings showed up but Polaris still showed through!

Don't worry guys, I'll still come visit!! I'm just too lazy to strip down and calibrate the declination gearing on the eq3 for autoguiding... along with modding the handset for the st4 cable... I'm impressed with all your results but it's not for me!! New job.. new laptop.. may as well get a new upgraded mount as well.. it's the one I always wanted and I can afford it now!

This might actually be my last picture on this thread as I'm collecting an Heq5 mount tomorrow!!

Thanks Peter, I saw your picture of this target the other week and hoped I could get something similar... The night I got this had patchy cloud as well, when I got only 39mins out of 2 full hours worth of subs, lets say my fingers were hurting from crossing them so tightly!! They're not so much stacking artifacts as they are me trying to remove the mess caused by the starlight reflecting off the inside of the OTA... this is what it looks like without removing the glare... Edit: Though there is a line running along the bottom that maybe due to stacking artifacts

Nice one nige, any plans to add some RGB? Managed to get this shot last week... 39x1min subs ISO800 with flats and bias, and for the first time shooting in RAW and stacking in DSS thanks to a new laptop I have been processing and reprocessing this one until I was fairly happy with it... The brightness of Alnitak was reflecting on the inside of the tube creating a light ring around the image... with a lot of careful gradient removal I was able to flatten it out enough to produce this image, which maybe looks like it has some vignetting but that doesn't bother me near as much as it did before! Obviously needs more data, but was good for learning to use the new software. Art

And a very nice pic it is too!! I haven't posted anything for a while as I changed job and now have early morning starts to deal with, so my free time for imaging has been compromised. What few sessions I've had over the last months I haven't really had great results... in fact to start with I thought I'd broken something when trying to image M74... this is 33 mins @ ISO1600 (can't remember the sub lengths, probably 1min) didn't realise just how faint this target is!! Next up was the triangulum galaxy... 58.5 mins this time in 30sec subs ISO1600... I thought this one would be a bit brighter but I was pleased to have captured some of the red nebulosity within the galaxy... And finally, with Orion taking centre stage in the early evening sky, I had to get the obligatory M42 shot... 55.5mins in 30sec subs @ ISO800... might give this one a reprocess at some point as I feel the background is too bright, maybe because it's a HDR target and I've only done one set of fixed length subs, so could probably do with more data and longer sub lengths. Enjoy, Art.

Had a bit of fun myself this week trying out different processing techniques... Made a last minute decision to get the scope out on saturday and shoot the pacman nebula, managed to get 1 hour of data in 30 second subs..... I was very disappointed with the result: This one with darks and flats. Then I thought to myself "I'm sure I've read people saying that darks don't always help and sometimes make it worse"... So I did a re-stack, same data, this time with no darks. Better, but I still wasn't entirely happy... So I had one more go... This time stripping the chanels down to R, G and B and stretching them/denoising them all separately before recombining in a new file.... since I'd gone this far already I also desaturated and slightly darkened the previous version and added that as a Lum layer, giving me a sort of "poor man's" LRGB image. Art

Hey nige, if you want to layer two different files/images, open them both separately, click on one the press Ctrl+A to highlight it, then Ctrl+C to copy it... click on the other file and press Ctrl+V to paste as a layer. If you want to blend them, look at the layer panel (usually on the right hand side of the screen) above the top layer there should be a drop down that's probably labelled "Normal" (this is where you select your blend mode) next to a slider that controls the opacity of the blend... have a play and see which ones you like. hth Art edit, only just noticed you already solved this... looking good!

seemless!!

Of course you can... It just requires a little more effort! @Nigel G cracking image!! Love the star colours and the faint Ha in the background... Wish I could call a 1.5 hour image a "quickie"

Had a little go at M17 the other night... only managed to get 38 mins though as it sits in a tight window from my garden, very low and close to the neighbours rooftops... Had man-flu all week so haven't bothered adding to it yet as seems like too much effort to carry the scope outside.

I managed to get nearly another hour on my Eagle Nebula last night, in between the clouds... Still found this one really hard to cut the light pollution from, but I'm getting more pleased with the results... So in total, this is 1 hour 44.5 minutes all in 30 sec subs, with darks and flats and 3 attempts at processing before I was anywhere near happy with it... well it's looking a lot smoother at least

I'm hoping to top up my Eagle nebula this week. Enjoy your sailing, you going anywhere nice? Ever drop a hook over the side?

Sorry, I've only just noticed this, been away on a summer break to Holland! Nice work Nige, how did you find out? nova.astrometry.net? @Stub Mandrel that last one of the Sadr region is great! Definitely less blotchy than the versions with the dark frames, there's still a slight grain running through it, not sure what the cause would be, but I'd be very happy with a shot like that! I've noticed some others on here swear by not taking darks, and just using flats and bias for their calibration frames, is that what you did?

Same here mate, I just did it to the jpeg too... I don't have a problem with gradex, it's a marvelous tool that simplifies the problem of gradient removal and you did a great job with it. I just feel it works better on galaxy shots than it does with nebulae... As always, the better the data you can put in, the better it will come out the other end... the more we cut out the gradient, the more of the nebulosity gets sacrificed in the process... it's a fine balancing act and that's why I prefer to do it manually rather than using the plug-in. More data will help, the stronger the signal you want to keep, the easier it is to get rid of the rest without disrupting it too much... if I can get another hour or so on this target, I'm confident I can get a smoother picture overall.

That gradex does look good, but I can get virtually the exact same result on Ps without it (see below).... I do think it takes some of the smoothness out of the nebulosity though, leaves it looking a little blotchy... I guess more data would help

Cheers Neil, will look into it.... Had another go at it this morning and managed to get a shot somewhere between the first two... the gradient is still there a little, but I think with more data it'll be heading in the right direction... M16 is tricky for me as it passes about 2 degrees above the roof tops, so in addition to street lights, you've got thermals to deal with too!!... Might be worth a trip to a dark site soon to make the most of it.

This is how bad the LP is since the town converted to LED... same image as the widefield shot from before (though I usually crop out the stacking margins, which I just realised none of you get with DSS!) but in this case I haven't done a gradient removal... just given it a stretch... and this is with a skywatcher light pollution filter!! The camera was on it's side so 'down' is actually to the right, and the moon would have been rising from the bottom of this picture (east)... That big wash of brightness coming from the right hand side... that used to be orange... then I got an LP filter and it was less orange... now its like THAT and it's a nightmare to get rid of without ruining the rest of the picture!.... I'll not be defeated though, I will find a way!!

Nooooooo they are NOT good for us astrophotographers!! They may be better for the economy, but that's about it! Normal (or old) streetlights, are made of sodium lamps, which emit a specific (though fairly broad) frequency of light which filters can compensate for... these new LED street lights are broad-spactrum white light, so even if you use a normal LP filter, the light still gets through.... I don't know if this makes a difference to narrow-band imaging?? but it sure puts an extra cog in the gears for DSLR imaging!! Hope you don't get them near you!!! Art.

Everyone seems to be getting on nicely with the guiding now... I want to jump on that bandwagon asap!!.... I'm not entirely happy with my input today... got these shots of M16 the other night, but was hoping to add to the data tonight for a multi-night decent pic instead of posting these now, but the forecast now looks better for tomorrow and I'm otherwise engaged..... So, here's 56.5 minutes on M16 taken in 30 second subs (I tried 30s simply to try and cut down on subs fit for the trash, otherwise I'd have gone for full minutes).... started out at 1600ISO and finished up at 3200... 100 shots of each (a little experiment if you will) threw half of them away as usual (really need to get guiding!!!) so I just threw the rest of them all into the mix... which if you've read previous posts of mine, you'll realise is a risky thing to do, but somehow I usually seem make it work... anyway, to be fair it wasn't a total flop, but an extra hour of data might help.... I tried processing it twice and came up with very different results... first up, widefield view of the nebula... not so happy with it as it seems to have a lack of stars in the left hand side of the image, and from the right was a LOT of LP which I had to get rid of... unfortunately this meant I was never going to get a decent background sky..... I tried, but failed... So I had another go... cropped it drastically this time in an attempt to stop the background distracting me from trying to make a nice picture... and to be fair.. same stack, but stretching it in a different workflow, with a different goal made me a lot happier with the outcome... Still can't get over how much LED street light conversion can really *&%$ over your astronomy! My LP filter just doesn't work any more!! Hopefully soon I can add to this data, but till then, feel free to show me your own more successful attempts! Art

I don't like to use the method to be fair, I've tried it a couple of times but I am never happy with the results either and usually just ignore the misshaped stars or simply don't publish it and try for a better version... I never posted my dumbell nebula because I missed the focus point and pivoted the sensor making my stars turn into - shapes.... I could fix it with the above technique but the nebulosity also gets affected, then you have to mask it off... but then the stars within the nebula are still - shaped....... It's a headache!! Best to just try again and see if you get better results next time