Filroden

I still think there is a slight bottom to top gradient. The darkest points at the bottom give readings of over 20 in R and 40 in B, whereas at the top they go to almost zero. However, I'm not convinced it's all gradient and some of it is nebulosity so I don't want to clip it any further. I typically like to not clip shadows. Although it means noise is more visible (let's be honest, we clip because our images tend to be noisier!) the eye is great at detecting pattern out of noise. Even though signal might be too low to enhance effectively with our processing tools, the eye can still do that final stretch. So I'd rather see it and spend hours debating whether it is or isn't signal than not see it at all. As a for instance, if you were to make an equilateral triangle, using Alycone and Merope as the base, with the point directly down, then I'm convinced there is a cross of dark nebula (close to the left of HD 23632 if you have a star atlas). Now I know there is dark nebula in the area but am I just imaging detail into my noise? That's why I love astronomy...you can dream!

I noticed my image of M45 had a gradient from the bottom (so probably light pollution). I didn't want to reprocess the image from the start (typically gradient removal is the first processing step) so I've done some crude post-processing of the image to try and minimise it. Not sure whether I'm trading gradient removal from the background for increased noise in the main image? Still, for 15 mins of lum and 5 mins each for RGB, I'm going to call this one done until I can collect more data.

Even though I had hours of frustration last night, the final result made up for it. Here's hoping you get to see something spectacular! And aren't eyes the ultimate alt/az mounted scopes?

Indeed and thank you. I think it loses something for being converted into a lower quality jpeg for the web but the full Tiff image on a large screen is breath taking. I think my PixInsight processing is not too dissimilar to the StarTools processes you describe. I still have to master masking as it's vital to being able to pinpoint which elements of the image to affect. I'm also learning how to use it's preview feature which allows me to apply processes to smaller parts of the image (reduces processing time) so I can tweak the settings until I find the result I like. I could probably push the data harder but I think I need to collect more before I really push the processing. I think what's impressed me most with this new imaging setup is that I'm finally happy with star colours. It seems to be much easier to balance the colours when you can work on each of them individually. Also the fact that SGPro makes capturing the data so automated. Once I've resolved the issue with my wifi connection to the scope and I can re-centre the scope every 5-10 minutes, I should be set for some longer imaging sessions. Next on my "to learn" list is whether binning the colour data improves things. In theory, I trade resolution (not so important for the colour channels) for improved sensitivity so I can take shorter colour subs to achieve the same effect (and therefore allow more time to collect luminosity, improving image quality/sharpness).

He's hopefully seeing red right now!

Well, my aborted attempt at IC1848 really was a mess. I didn't process the 30 minutes of data I collected without cooling but I've just run the 15 mins of lum and 5 mins each of RGB (all 30s subs) through PixInsight to see what I achieved. It rejected some of the frames (mainly in from the already minimal RGB). I ran out of time on this object as it got too high in the sky and my filter wheel was getting perilously close to the mount. It's not pretty. There's some serious star trailing going on which I think is down to me letting PixInsight manage frame selection. I also had to heavily crop it (it was badly framed to begin with). Nonetheless, given this is effectively on 15 minutes of lum and colour data, it's not far behind what I captured with nearly 2 hours of a DSLR I think this is a target I need to revisit next year once it's returned to lower altitudes (or I start doing early mornings rather than late nights). I'm really glad I swapped to M45 for 30 minutes after this!

That's a lovely image. The reduced stars really makes the nebula pop. You've really captured some lovely detail in there.

I'm as pleased as punch with it. Definitely my best shot so far and it's only 30 x 30s of L and 10 x 30s for each of RGB. Can't wait for another clear night where I can get longer on a target.

Here goes: my first LRGB image using 30 second subs on the ZWO ASI1600MM at -20C with a gain of 300. Processed in PixInsight.

It's definitely much clearer - you can see the full extent of the Heart Nebula now. Wavelets are great for pulling apart an image into different structures and giving you the control to sharpen/noise reduce only those structures you really want to (whether it be the lowest wavelets to reduce noise or the higher wavelets to improve sharpness or contrast). It took me a while to wrap my head around wavelets (having first come across it processing planetary images) but now I think it's a great tool along with various masks.

Yes, I'd wasted so much time setting up then messing up the first 30 minutes of subs that I swapped to M45 given its a much brighter target and I was running out of time/stamins. I did capture some subs of IC1848 which I will also process but given the run was short I don't know what to expect. SGPro seems to only allow a minimum of 1 second in its framing and focus module. I did finally manage to align using SGPro and the handset, it just takes a lot more patience. I need to figure what's wrong with the wifi though, as using the handset is a pain compared to controlling the scope from the iPad using SkySafari.

I have yet to take flats (scope/camera is sat in the lounge ready for me to run them) so my initial integration suffers from vignetting. Here's a single, bias/dark calibrated, L sub of 30s with no processing other than to convert the fits file to a jpeg (first image). I also applied a very quick stretch with levels and curves (second image). I've applied no noise reduction, etc. Now off to take the flats.

You just know it's going to be one of those nights. It's clear, the wind has settled. The scope is set up. The camera is working. I even managed to get it focused using SGPro - not easy when you're fine tuning and waiting a second for the image to update. Nonetheless, I have to say this is the best focus I've ever achieved. Stars looks *sharp* on the screen. And then it all went wrong... It's almost impossible to do a three star alignment using SGPro and 1 second image capture. I need to find a better "live view". I persevered though. Until the fourth failed attempt and I decided to get the DSLR and use that and BackyardEOS to do the alignment. Success first time! And then it all went wrong again... The wifi on the mount decided to bug out and I couldn't control the mount from the iPad. I tried everything, even powering the mount down (knowing I would have to realign it). I tried connecting via SkySafari, Celestron's own app, through the iPhone and the iPad. None of them would connect. I finally gave up and got the old hand remote and tried to remember how to use that. Anyway, a quick two star alignment later and I was centred on IC1848 and taking my first 30 second L sub. I'm now running a sequence of 10x LRGB at 30 seconds and I'll keep repeating that for as long as I have the stamina (probably recentering after each sequence). I have to day, I don't know if I've captured any nebulosity but the star field looks much nicer that anything I've taken before. Fingers crossed! P.S. Remember to plug the power into the camera's cooling. That's 30 mins of subs taken at 11C rather than -20C.

I think it might but I've never needed to find out yet. It can cope with mosaics (but so does DSS). I think it's down to alignment (both PI and DSS do this) and whether it has a function to rescale if the images can be aligned but are of different scales. I can't think of a case where I could test it given my equipment until I can set up some wide area imagery with my stock Canon zoom lens (but that's another project once I've learnt how to use the camera on the scope!).

Normally that would be try but because our mounts introduce field rotation, won't the distortion rotate too? But I think you hit the nail on the head, it's possibly the zoom causing image scale. I'm not sure whether DSS can align and rescale subs? I've never had to merge images from two different image trains (effectively what a slight change of zoom creates) but I know it's possible.

Weather is looking promising tonight. I need to measure my spacing on the camera from the reducer. i don't have the spacers I need to get it perfect but I'm hoping I can get it close enough to test it tonight. I know I can reach focus (tested on the refractor already). If the wind dies down, then I think I'll try for the Soul again - maybe 60 mins of L and 20 mins each for RGB (bin2). Given the extra sensitivity, that should be more data than I've previously captured using the DSLR though it would mean having to learn how to upscale binned data. I'm more scared about the processing than the capture! There's something I love about globular clusters. I also love that you can just start to see some diffraction spikes on some of your brighter stars - something I love to see on star fields (not so much on when the focus of the image is a nebula or galaxy).

Your Soul is definitely more Elvis than Baby! I still find it amazing what you can capture in such short exposures. I definitely want to try more wider frame imaging. There's something weird going on in the Heart. It's almost like DSS isn't aligning the frames right on the left hand side and it's introducing a noticeable blur. I don't think it's our normal "friend' of field rotation. I wonder if that's lens distortion? Did you have the aperture wide open? If so, it might be better to drop it down a couple of stops. If not, do you have either Lightroom or Photoshop? Both can "undistorted" lenses. In Lightroom you tell it which lens you are using (it can often auto detect it from the RAW metadata) and it warps the image based on known distortion models for that lens. Unfortunately, you have to do this on each sub individually then re-save/export each file. I'm not sure if other photo packages can do the same (it's a feature of Adobe Camera RAW module which is included in both Lightroom and Photoshop). You would probably have to do this with lights, darks and flats, as they would all have the same distortion. (I'm out of my depth on this part having not used wide angle camera lenses yet)

If I remember right, DSS has tabs you can load your different length subs into and it works it out from there. In PixInsight it scales the darks to match the lights (so long as the dark is at least as long as the longest light) as dark current should scale linearly. I've just taken a set of 120s darks as that covers me for anything I can do with my mount.

I pretty much have those issues with the DSLR. I use a laptop with a 3m USB cable as I found it easier to focus and frame on the laptop screen than on the camera's live view. I found my mount goto was much more accurate using the laptop, helping me centre objects first time. I'm going to try a new set up now the nights are getting colder. The new camera needs power for cooling so I only have one extra cable to deal with. I can set up the laptop in the kitchen and both the USB and the power cable should reach the scope easily from there. I only have an easterly view from the garden anyway, so I don't have to worry about cable wrap. I also figure that the increased sensitivity of mono should mean I spend about the same time capturing LRGB as I did with OSC. I also don't need to pause between subs, whereas with the DSLR I would build in a 6 second pause to allow the mirror to lock up and for vibrations to settle. I'm more worried about the processing. Calibrating, aligning and processing four images rather than one just means I have more opportunities to miss something or mess up something! Anyway, still 100% cloud cover atm though it's not forecast to clear for another couple of hours. Scope is by the backdoor ready.

Not yet. I had a really clear night on Sunday but I'd just returned from a 300 mile journey and hadn't tried the camera in daylight so I missed the opportunity. I now have it working and tested. I'm having to learn a new capture software (having loved BackyardEOS) and it's certainly slower to find focus but I have a set of bias and darks all ready captured. Tonight could be clear but they are forecasting very strong winds so it's 50/50 for tonight. If I do get out I may go for the Soul again (as a comparison) or for the Pinwheel (given it's both low and to the East). If the wind is kind and I have the stamina, I really want to image M45. It was one of my first targets and I got nothing but stars the first time so now I've had much more practice I'm hoping I can capture something more.

Hi Nige Here's my attempt. I also struggled with the gradient and because I couldn't effectively remove all of it, I was left with a lot of residual noise that I couldn't remove without losing signal. There is definitely a lot of colour in the image and you can clearly see it in the Veil. I think with flats (and possibly without using darks) you may reduce some of the effects. I think the Veil is too high for me to image right now, but it certainly looks a nice target. I hadn't thought to include it on the list.

I believe it's Stock 2, an open cluster (from SkySafari).

Ian, that's a stunning image. The stars are incredibly tight and the detail you've captured is amazing. It just goes to show what's possible! The only thing I might have changed is to make the galaxy core closer to white by either dialing back on the yellow in Photoshop or Lightroom, or making the white balance a little cooler. However, you've got great colour everywhere else in the image.