Filroden

I wonder if unchecking that option might make a difference?

Very odd indeed though my backgrounds typically start green and I let BackgroundNeutralisation and ColourCalibration work their magic. I think it works in a similar way to auto-fixing white balance. You show it a known area of neutral background (akin to picking a known grey shade in daylight photography) and it then balances the colours. I therefore wouldn't be worried about green backgrounds if they can be corrected in software. However, to have two such very different results! The big difference between the two images is their altitude. M45 would have been low and in light pollution maybe (making it very red heavy before correction) and the Veil is very high. Maybe that's all it is? In DSS, do you select the option in the stacking settings that balances the colours (think it's at the bottom of the first tab)?

Welcome Jon. That WO66SD should give a nice field of view. Can't wait to see your results. Do you have some targets in mind already?

I'm just impatient. It currently puts Pacman, Iris, Veil, NAN, etc out of reach until next summer unless I carry the kit to another site (and that means figuring out battery power). I've probably got a limited window on Soul so I might try and frame it horizontally and see if I can't fix the issues I had last week. Update: just checked and it looks like both Pacman and Gamma Cass are within my altitude limit for about an hour.

I have two projects for the daylight hours today: 1) Squeeze an extra 5-10 degrees of altitude out of my mount. Moving to the new camera really extended my imaging train and it has reduced how high I can image. I think I can get more altitude if I turn the camera upside down as it moves the bulk of the filter wheel away from the mount. I'm also going to see if I can move the scope further up, though its dove bar is very short. The DSLR was small enough that it could almost clear underneath the scope and allowed me to get to at least 75 altitude. Now I's scared to go near 65, which is really limiting my imaging options. My mount was definitely not designed with imaging in mind! 2) Take an all-sky panorama to load into SkySafari so I can better estimate when targets are clearing the houses/street lights. I hadn't realised how little sky I can actually see when I bought the house. It initially looked like I could see half the sky from the patio but the height of the houses plus the three street lights leaves me a small cone from roughly NE to SE and from 20 to 60 altitude (with the ideal imaging altitude being around 40 to clear the light pollution but still stay low enough to reduce rotation) I could move the scope to the end of the garden and recover a little of the western sky but that relies on my first project being successful and also means I have to leave the warmth of the kitchen and sit in the garden (and means trailing an extension the length of the garden). Update: regardless of where I move the dove bar, the highest I can go without camera contact is 71 degrees. If I don't rotate the camera/filter wheel that reduces to 66 degrees.

Hi Nige This is a strange one. I can clearly see the green in the first image but the same effect is missing from the second. Did you change some of your processing steps between the two images? One thing that jumps out at me in the first image is that it is the cores of the stars which are green. Their halos all seem to carry the correct colours (reds, whites and yellows). It's as if the cores are over-exposed and some process you've done in StarTools is highlighting/masking the star cores and affecting just them? I had a play with the jpeg in both PixInsight and Photoshop. I couldn't do much with the star colours - I could reduce the green but I couldn't re-tone the stars. However, it has a great little tool that reduces star sizes and when I ran that, the Veil lifted! A little brightening in Photoshop later and ... That's a lot of Veil you've captured there. Nicely done. I think it's quite a tough target even with long exposures. One more thing springs to mind (and it's been mentioned a few times in the thread), could the colour issue be something to do with debayering and therefore to do with that initial setting in StarTools? Alternatively, is it a setting in DSS?

I'm thinking about it though I prefer the wispiness of M45. I know a good printer in East London but I'd like to see if I can find one locally that can handle astro images (shades of black are much harder to print!). I'm going to put it and a couple of other images onto a memory stick and test them at A4 and A3 to see how they work. Alternatively, I might see about A5 and create something with a few images (and maybe a little text) too. Another project for a cloudy night!

Okay, one final version and I will stop tweaking (at least for today). I took the original image into Photoshop, cropped it and then rescaled the image to fit approx. A3 at 300dpi. I applied a little vibrance and a small S adjustment curve to enhance the contrast. I'm much happier with this than the linear stretch I applied in Lightroom which I think just clipped detail rather than enhanced contrast. Tiff attached. M33_20161002_v3.tif

I can't really image the California Nebula until around 23:00 and I can only image the Soul before about 22:00 (the Heart is too big even for a two panel mosaic). The Pacman is already too high. The real test will be in a month or so when I can get my scope onto the Rosette, Flame, HH and Orion nebulae. The weather here is nice at the moment but the forecast is saying low cloud cover moving in around 20:00, but tomorrow is still looking promising. I have the scope still set up from last night and sat on the dining room table so it won't take me long to set up if I get another dark night.

I had a broad gradient running from bottom of image to the top, plus some vignetting because I didn't use flats, which AutomaticBackgroundExtraction took care of. I also had a fairly large dust bunny just to the south of the galaxy and about 25% of its size. I modelled this carefully selecting many points in and just outside the dark area avoiding selecting anything in or near the galaxy and DynamicBackgroundExtractor took care of that after two applications. Otherwise, I was fairly blunt with noise removal in the colour channels, and applied MultiscaleLinearTransform noise reduction to first 5 wavelets (in decreasing strength) before stretching and then, with a lum mask, a little more MLT after stretching with some TGVDenoise thrown in. I also (with use of galaxy and star masks) applied sharpening and unsharp to the galaxy to enhance the finer details. I enhanced the contrast with some HDRMultiscaleTransform. I still have a lot to learn in terms of processing - my masks are still very "wild" and could be created with much more refinement. I also still haven't wrapped my head around deconvolution (though at least now I can use it) or LocalHistorgramTransformation (which I didn't use). P.S. Should have added, if you check the original version I posted (not the black clipped version I did in Lightroom) and zoom right in (you may have to download the image), you can see there is some very fine noise in the galaxy but nothing that detracts from the star forming regions or areas of nebula (which are much easier to see zoomed in).

Like so?

Well, here's my first result for M33 Pinwheel Galaxy. Captured using SGPro and processed in PixInsight. This comprises 81 x 30s L, with 34 X 30s R, 35 x 30s G and 33 x 30s B for a total imaging time of 91.5 minutes. Here's an annotated version too, as there are lots of additional fuzzies in there! P.S. Here's a slightly tweaked version having taken it into Lightroom.

Likewise, M33 is definitely there. My L subs are noisier than I would like (a by-product of the LP so I must either image later or select higher targets for the early evenings) but the RGB is looking nice. I had a very nasty dust bunny which took two iterations to remove (which probably means I've created other gradient issues in other parts of the image). I probably have another hour of processing time left this afternoon (pre-processing is pretty automated so I can leave it running in the background). I'm guessing this will be one of those images that I will never be happy with the "final" version and will become a feature of re-processing every cloudy night!

Ok, I took flats this morning and they looked far more normal than the ones I took last week. I used the sky with a lot of paper over the scope. However, for some reason, SGPro couldn't calibrate the G filter and it took me ages to find the random combination of changes that would make it work! I've just calibrated and integrated my files and the flats seem to add dust bunnies, not remove them! So attempt two now in progress without flats to see what the difference is like. I did learn a few more things last night. My USB cable from laptop to camera is long enough to reach the scope from the kitchen but as M33 rose higher and moved to the east I must have reached it's limit at some stage as my subs started to show double stars or trails. Thankfully I caught it quite quickly. Also, my mount does love to slip, so I do need to visually inspect each image before accepting it into the stack (I'm "cheating" and using a batch process for calibration/integration so I no longer have PixInsight analyse each sub for quality). Combined, the effects of both these meant I lost about 10 minutes of subs (and I still accepted some subs which showed borderline trailing). I also probably started imaging M33 too early. The first 30 mins of subs show significantly more gradient than the final hour when it was much higher. I guess my imaging sweet spot is between 40 and 60 altitude. That said, I will have to wait and see what PixInsight can do with the gradient. Given M33 occupies much less of the field than M45 or IC1848, it will be easier to identify and remove the gradient without destroying signal. At one point I tried to increase exposure time to 60s but I think this coincided with the USB cable getting tight so I discounted the result thinking I was seeing trailing when in fact it may have just been tension from the cable. Something for me to test next time, as it will be much easier to process 100 60s images than 200 30s images (and also reduce the total file size from over 7Gb to 3.5Gb!).

If I can get another early start I will give the Soul Nebula a proper run as it's still low enough before 22:00. Tuesday is looking good on the forecast. Yes, I lived in Somerset until August. I moved North so my skies are very different. I have a much more restricted view, only seeing from NNW to SSE with street lights to the NE. However, I think I have less light pollution now and can see the Milky Way which was impossible where I was.

So far I've got 90 x 30s L and 30 x 30s each of RGB. I'm hoping to do another 30 mins more and then see if Auriga is high enough to clear one of my street lights.

Can't wait to see your results. It's just starting to attain a nice altitude.

Isn't it great to be imaging at 20:00? My mount played nice tonight and wifi connected. I figured how to speed up the frame/focus module in SGPro (it does capture images of less than 1 second plus binning 4x4 really helped the speed) so alignment was a breeze. I had tried to improve the spacing on the camera to the flattener given I'd just thrown it together on Thursday. That caused the first big hiccup, with my first images showing all sorts of weird! Reverted to the original spacing which I think is too long but at least my stars are now round and point like, rather than something Monet would have been proud. So, given it's so early I decided to give M33 a try. It's small on my sensor so it gives me a lot of latitude for cropping later. However, the forecast shows clouds could come at any time

Thank you for taking a look. I think you're right and there is still gradient in my image. I think I will give it another go tomorrow and really spend some time on gradient removal, particularly in the red channel. However, some of that blue could still be light pollution. I have three LED street lights around the garden and the town has LED in most streets so it will seep into all three channels.

I think someone will sort out a combination including the Raspberry PI, running capture software, some attached SSD storage and a small screen. Until then, you can attach the Raspberry PI but you have to remote connect with a computer - at which point you're doing what I'm doing but with one more piece of kit! I've just managed to wifi connect my laptop to the mount which means once aligned I think I can control the mount and goto from the laptop, removing the need to keep the iPad. I'm going to trial Nebulosity as it runs on a Mac. If I like it, then I could have simplified my own capture process (though SGPro does make taking flats a piece of cake). One more benefit of the camera - its higher resolution made getting a sharp focus trivial. I've never seen such a clear diffraction pattern from the Bahtinov mask before.

Here's a few explanations that I could find. My L integrated image is definitely more detailed than the combined RGB image. http://www.robgendlerastropics.com/LRGB.html http://astro-imaging.com/Tutorial/LRGB_I.html

For me it was effectively a one-for-one replacement for the DSLR as I was already tethering the camera to the laptop to allow me to sequence images (and with a very long USB cable so I could do it from the warmth of the house!). The filter wheel connects to and is powered by the camera so the only additional lead I now have to manage is the power supply to the cooler. The filter wheel is fully ASCOM compliant so I just set up my sequence and let it run for 30 minutes, in which time it's captured 30 L and 10 each of RGB. (I've not yet really tested the different focal points of the four filters so I'm probably introducing some blur if they are not par focal). I can then re-centre the object (I find that helps over time - the mount can track but it eventually starts to go wayward) and then repeat the 30 minute routine. Plenty of time to sit and watch TV! So far the noise levels have been brilliant. It was so much easier to process the images, even with such limited total integration. In fact, I could probably have skipped noise reduction entirely and still had a cleaner image than a much longer DSLR image with noise reduction! One of the biggest immediately noticeable difference is in the colour noise. The bayer matrix on all OSC DSLR really does introduce a lot of colour noise. Particularly for us given it's constantly rotating so each pixel over time swaps from picking up R G G then B. I found my backgrounds looked like ants had crawled through the picture with paint on their feet! What noise I now see is an order of magnitude less noticeable. So for me, I've gain a couple of huge benefits from the swap: - I'm now imaging at the full resolution of the chip, with every pixel equally sensitive to all colours (including deeper into red) compared to the DSLR where only 1/4 of the pixels would read red and even then it was only 25% efficient at the Ha band. - the cooling removes much of the noise and its very low read noise means I can capture signal in much shorter subs. - I get more natural colours when I combine the RGB and it's much easier to balance. - I don't have to worry about mirror vibrations, so I've speeded up my capture rate (6 seconds pauses between images is a lot when the sub length is only 30s to begin with). There are some negatives: - because of rotation and the way I'm currently sequencing, my final filter subs (B) are much rotated from the initial subs (L) - I can probably address this in two ways a) ignore it, 60 subs with OSC go through the same degree of rotation so I would be cropping anyway and b ) rather than take 30 L then 10 each of RGB I can take 10 sequences of 3 L and 1 each of RGB - I think a) is the right way for me to think about it but I will probably do b ) because it means I have some colour data if clouds come over. - it takes a little longer to process because I have to integrate four sets of subs, crop each of them (trivial), remove gradient from each (though I could remove gradient from RGB after combination) then work on L and RGB through noise reduction and stretching before they are finally combined into a single LRGB image for final processing. That said, I've become faster with each try so other than the initial integration, the processing feels like it's taking similar times. - I need more storage - each channel takes 32Mb. Given we are limited in exposure, having a much more sensitive camera with lower read noise and lower noise overall, really helps reduce some of the gap we suffer from not being able to do guided long exposure subs on an EQ mount. Once I get to grips with SGPro and can align the scope quicker, I think I'll be able to capture much higher quality subs than with my DSLR. Though I think Nige has it right with modding the camera to make it more red sensitive - though even with 100% QE on red, you're still only using 1/4 of the pixels to capture it. P.S. I also realised why my IC1848 had star trails - it was at a very high altitude so 30s was probably too long given it was more to the NE than E.

Look's like I might have a clear night on Sunday. Any thoughts on which of these might be good targets? The California Nebula would need to be a two panel mosaic so I think that might be one too many complications for me to attempt so soon with the new camera. Has anyone tried for the nebula/clusters in Auriga? P.S. I've just found out that you can double click your images when creating your post and reduce their sizes!