Gina

Still nothing

Run again and it retrieved files from cache saving a lot of time but we'll see if it displays anything...

OH!!! The processing has finished but no images on screen I did the same as last time so I don't know what I did wrong. I guess I can try running it again...

Finished and master bias saved as XISF. Now running to 600 set. Put these into the 500GB SSD rather than using the HD. Processing is faster with 6 frames in 5s. Now stacking pixels. Here are the two screenshots of the process for 300 and 600 bias frames. I wonder why the 300 set uses 63 concurrent pixel stacks whereas the 600 uses only 31.

Now integrating pixel rows - this takes a while... I noticed that the settings were different from those used in BPP. So, all-in-all I would expect an improved result.

Now running ImageIntegration on 300 bias frames using the settings recommended in the book for a large number. Each frame is taking just over a second (about 4 frames in 5s) so something like 6-7 minutes processing time.

Now downloading the bias frames to my Linux Mint desktop ready to integrate in PI. Doesn't take long with gigabit Ethernet link

I've just completed 300 bias frames but I'm wondering if anything would be gained by taking yet more. The 300 didn't take long. I guess I could take another 300 and do a comparison between the integration of 300 versus 600 and see if I can see any difference.

I gather fixed pattern noise is handled by bias frames. I agree with your reasoning about number of darks. Yes, this book is based on either DSLR cameras or CCD astro cameras - the ZWO cameras designed for astro use are a pretty new innovation and a different beasty from either, so a bit of "intuition" is needed in interpreting the information. This is a new experience for me after a year or so of DSLR imaging followed by a couple of years of high quality astro CCD imaging. Big and noisy to small and quiet and now to big and less noisy. So latest thoughts are - several hundred biases, maybe 50 or so darks and as many decent lights as possible. I see it's unnecessary to take special darks for flats as the "Optimize" parameter can be used to correct for the shorter time used for flats but I'm not sure this will work with the lower gain used when taking flats - I don't remember reading anything about this.

I shall need to read the Calibration and Integration section again to take it all in. So far I've gathered that several hundred bias frames are required and I've just read the suggestion of twice as many darks as lights. Now one of my sets of lights amount to 250 frames which would indicate 500 darks. 500 x 1m darks is over 8 hours - this is getting ridiculous! Maybe the 250 lights want pruning to select the very best. I gather that adding extra poorer quality lights can degrade rather than improve the result - so fewer really good lights should be better. Seems PixInsight works rather differently from DSS et al and uses different ideas to obtain improved results. This is all very interesting and encouraging but I have an awful lot to learn!! Good job I like learning

Thank you Ken - that sounds a good idea One thing I've just learned is that you need hundreds of bias frames and I've been using only 100. As you say taking several hundred bias frames is no problem though a lot of data. OTOH I have arranged to cater for vast amounts of data and 10GB for 300 bias frames is no problem.

More reading of the "Inside PixInsight" book has been very interesting and I have learned a lot more. I can see better ways of processing my data and learned more about the relationship between bias, dark and light frames as well as shortcuts to taking and calibrating both lights and flats. I know the calibration I have been using has left a lot to be desired and I can see ways it can be improved including SuperBias.

I really can't see any treatment of a DSLR coming anywhere near the performance of the ZWO ASI1500MM-Cool. There may have been improvements in DSLR technology but I can't see any reason for manufacturers of DSLRs to make them that much better for astro imaging, the scale of users would simply not warrant it. And if such a camera were available it would be bound to have a similar cost to the ZWO camera. When I was experimenting with debayered DSLRs I was comparing with CCD sensors at two or three times the cost of the ASI1800MM-Cool. I certainly spent more than one of those ZWO cameras cost had they been available.

And a couple more akin to the FOV of my 135mm lens.

Here is an image from Wikipedia which covers a nice FOV similar a bit smaller than my 200mm lens.

First screenshot shows the relative FOV with the 135mm f2.5 lens - my current setup plus position of the moon tonight. A narrower FOV might be better but there is quite a lot of nebulosity in the neighbourhood and this lens is excellent. Next up is the 200mm f4 and then the Esprit scope with 400mm f5. These are shown in the second screenshot with biggest rectangle the FOV with 135mm lens then 200mm and smallest the scope.

Seeing the Jellyfish Nebula (IC 443) in the DSO forum, I thought I'd check just where it is with the idea of imaging it when we next get a clear night (probably be several days yet though) BUT it's right next door to the moon so will have to wait for quite some time yet, until the moon is out of the way. Even with 3nm filters I think the moon is likely to be a problem. I might just see though Here is a screenshot of CdC for 10pm this evening

Well, I have 92 frames that contain some data. A few of them have fairly good images but more than half are pretty poor so I have a dilemma - take maybe a dozen or so good frames only or take the lot. My feeling is that "poor" extra data would not improve matters.

Been going through last night's subs and as I expected far more duds than good ones - I could see the clouds passing over except when they were continuous, then the frames were just white. So far I've gone through about half of the 400 collected. Rather a tedious job but considerably helped by Blink in PixInsight.

I'm now capturing OIII subs of the NAN with 60s subs with gain of 500 and -28°C between patches of cloud.

Gone back to 2016-10-13 for Ha subs of the NAN & Pelican. Processed with BPP in PI and then histogram stretched and slightly cropped in Photoshop. 30s, g=440, T=-30°C.

Just processed the SII Cygnus Loop subs I captured the other night. Firstly, I used Blink in PixInsight to weed out the duff frames of which there were a fair number, mainly due to passing clouds and finally to complete cloud cover. The result was 52 reasonable frames which I calibrated with the bias and dark frames I took the next day plus my latest master flat using BBP in PI. Here is the result with further processing in Photoshop to histogram stretch, rotate and crop.

There's patches of cloud coming over but I'm hoping it will go away.

Clear sky tonight as forecast Capturing SII subs of Cygnus Loop. Tried 120s but got oval stars so the PA has gone off a bit - it was alright up to 5m. So I've gone down to 60s and increased the gain by 12dB (560 on the gain scale) which is just 4dB below maximum gain. I think this should work - here is a single sub, histogram stretched, rotated and cropped.

Here's the SII master light, well histogram stretched, rotated and cropped in Photoshop. It's out of focus as well as faint but the forecast for tonight is looking good so maybe I can capture a replacement set.