Gina

The ZWO cameras are far more sensitive than a DSLR but the one that closest matches the pixel count of a DSLR is the 1600 with 16Mpx but yes it's their flagship camera and expansive - less so than CCD cameras though. I'll check up on the specs of their other cameras - a comparison table would be useful.

Yes, I have 3 ASI cameras but they are very different. I first bought an ASI185MC for planetary imaging which I tried in my all sky camera. Then I decided to go mono for higher sensitivity for the ASC and bought an ASI178MM camera. Finally, having sold a little piece of land giving me some extra funds I bought the ASI1600MM-Cool for DSO imaging. They all seem very sensitive. On the ASC both ZWO cameras were much more sensitive than the QHY5II-C I was using and with very little noise - the QHY was very noisy in comparison. I imagine the sensors would be very similar in sensitivity per square micron of pixel size. Cooling helps enormously with noise for longer exposures eg. I use 60s for the ASC and have added my own Peltier TEC cooling which makes quite a difference. Of course this is not a patch on the proper cooled cameras as they can take the temperature much lower and have desiccant tablets in the sensor chamber to stop misting up. A cooled camera would be nice on the ASC but with the exposed position I don't think the damp would be very good for it. The non-cooled version I'm using is in a sealed enclosure to keep moisture out and the cooling uses thermal conduction to the aluminium mast rather than air blown fins.

I seem to have rather strayed off-topic in this thread but I guess the hardware and software involved is quite appropriate I now have two SSDs - one of 250GB and one of 500GB together with mounting hardware and sata cables. My original idea was to use the 250GB in my new desktop with Linux Mint and PixInsight etc. and the 500GB in my Win7 desktop which is using a 500GB HD as drive C: and which could simply be migrated to the SSD. However, it now seems to me that the bigger SSD would be more benefit for use with PixInsight etc. I think I can use Linux to reduce the C: partition on the boot drive from nearly 500GB to under 250GB as I'm only using 200GB ATM. Then the C: "drive" partition could be migrated to the SSD. Any thoughts on this would be much appreciated

In future I can just transfer files from my observatory laptop (or RPi) directly to my new desktop for use in PixInsight which I'm liking more and more as I use it and watch tutorials. I'm fast becoming a convert I might even use PixInsight as client to INDI when I get the RPi setup working. Haven't looked into that yet. I'm thinking also of using the new PC to control the Win7 desktop as a server for remaining software that doesn't have a Linux version, using TeamViewer. I've already been doing this in a small way.

The gigabit Ethernet switch has arrived and I've connected it up hoping the transfer rate between my two desktops now connected to it would be much better but it isn't The data link is showing 1000Mbps but I'm only getting 80Mbps. viz. 3GB is taking 5m to transfer across. Could it be a slow HD? Or is there some other explanation? One is sata 2 the other sata 3 - don't know anything else about them except one is 500GB and the other 1TB.

Found it would save in various formats in Save As so I saved in FITS, transferred to Win PC, converted to TIFF and resized resized in Ps. No other processing.

I was hoping to post the preprocessed image I have in PixInsight but it's in XSIF format and I can't find anything other than PI that will read it. I imagine there's an export option in PI but I haven't found it yet.

Definitely the conditions - most frames were total cloud! I'm quite surprised there's anything there TBH.

Very little there - DSS chose just 25 out of 85 Lights and this is the results of histogram stretching in Photoshop. I'm playing with PixInsight and getting familiar with calibrating, registering and stacking in that. I'll try this lot in PI and see if the result is any different.

Transferred the Lights and been through them just in FITS Liberator but there doesn't seem to be much, if anything, there. Now transferring all the darks - seems I captured 200 of them which is probably overkill. Once I've got the darks indoors I'll run DSS on all I got last night and see if there's any sign of the Cygnus Loop. At least I shall have stacked darks and bias frames so next time I'll not need to do that again for next time - assuming I use the same settings. These are at -25°C and gain of 600 - the maximum. With this much gain I shall need bias and dark frames.

Some clear sky last night but also lots of passing cloud so I don't know what I got until I look at the subs. I set up for taking 30s lights of the Cygnus Loop with the 3nm Ha filter but at first it was too cloudy so I took a pile of bias frames followed by darks. Part way through the darks I noticed a break in the clouds so took the cap off the lens and replaced the dew shield and set up for Lights. Took quite a lot but then saw that the sky had clouded over so stopped and went back to darks. Closed the roof and flap, put the cap on the lens and set up for 100 darks and went to bed about 2am leaving it running. This morning I'm transferring data from obsy laptop to desktop indoors. How awaiting delivery of hardware upgrades including SSDs etc.

Processing Cygnus Loop subs. Here are the stacked and histogram stretched images from 49 x 5nm Ha , 94 x 3nm OIII and 98 x 5nm SII though the Ha is not stretched - it's just as stacked. Images cropped and resized etc.

Which capture software are you using? I found oacapture won't work with exposures longer than a couple of seconds - James is looking into it but not come up with a solution yet.

With the amount of Ha nebulosity in this region I feel I would like to go for an even wider FOV. I might go for a 55mm f1.8 Asahi Super Takumar lens. That would give around 17° FOV in width rather than 7°. That certainly won't want guiding Particularly if it works alright at full aperture.

109 of 112 30s Ha 3nm subs of NAN & Pelican stacked in DSS and histogram stretched in Ps curves to carefully bring out as much faint nebulosity while keeping the whites from saturating. Resized to half size - 2328px wide and saved in PNG format. This resizing is a compromise between full frame which takes at least 5m to upload and 1200px which is the standard display size here.

Thank you Did have PixInsight as a fallback option though - if I can get it to work

I'm thinking I may use both desktop PCs for astro image processing and other purposes. I will evaluate PixInsight during my 45 day trial period and see if I get to like it - I like the idea of scripted batch processing to do the mundane tasks such as registering and stacking but I'll have to see how it goes with further processing. There's software other than Photoshop that is Windows only - I think SketchUp is only Windows and Mac and I need that for designing my 3D prints. I'm thinking an SSD drive in the Win 7 desktop could transform it. Not only in speeding up software but for a swap-file that is almost as fast as RAM of which there's only 4GB. If I got a big enough one I could store files there temporarily for faster access.

Been carefully going through all the settings in DSS and have at last found why it was only using 50% of subs for stacking - found the setting and it was set to 50% so I've set it to 95% and trying again. A bit later... Yes - that was it It's stacking 47 out of 50 green subs for M31 which is 95%. Maybe I could set it higher eg. 98% would throw out the worst sub of 50 or the worst 2 of 100 etc.

"Ma bwain hurts Bwian"... bee reading PixInsight tutorials Can't have DSS throwing out half my data for no apparent reason though. Read tutorials on that too and I'm not much wiser!

The data transfer is taking rather a long time so I checked the line speed and found it to be 100Mbps. Tracked down the problem to the BT Home Hub which has only one gigabit port The other three are 10/100 only so I've ordered an Ethernet switch so that I can get gigabit data transfer between wired computers. The one I'm getting has been tested with the BT Home Hub as it appears many Ethernet switches won't work with it.

Too simple really I was trying to be too clever - I unpacked the deb file, which was wrong. It's simply a matter of right clicking the packet (xxx.deb file) and choosing "gdebi installer" that installs the software "simples!!" TeamViewer 11 is now up and running on the new PC and I'm transferring a 100+ subs from Win PC to Mint PC (using wired connection). Using the Win7 PC as client and Mint as server didn't work so I did it the other way round. Neither machine will be "headless" so it doesn't matter. Win7 is running TeamViewer 10.

It's covered in Linux Mint info

I have downloaded TeamViewer and extracted but nowhere can I find how you install it. No readme and nothing on the web site Maybe I need to look up general Linux stuff as it's a .deb file and I think I've installed these before but can't remember.

I forget...

Now downloading TeamViewer for Linux. It's what I've used as a cross-platform app but is it the best?