JSeaman

No but that would have showed in PHD2, the thing I can't explain is it thinking everything was good

I just had a really strange anomaly and I'm wondering if anyone has seen it before The effect is shown in the images below, I suddenly got significant trailing for 20 minutes on 4 different subs: Not unusual in itself but the guide log was at a steady 0.6" the whole time and showed no deviation in RA or Dec. Has anyone seen a clean guide log and trails this bad before? James

Thanks, definitely my best yet and I only took it because I was there using it to align the scope. I'm actually doing Merlotte 15 tonight but really pleased I spent a few hundred milliseconds on it!

The 1600 definitely seems bandwidth heavy over USB. Drivers has to be a good place to start if you're not using the native ones then I would switch. It is worse at the point of taking an image so I set PHD and Nebulosity (SGP in your case) both at 1S so I could fault find better.

Yup, it's definitely that - in PHD2 you can see it updating every 1 second until you start taking photos on the 1600 in Nebulosity then it is really laggy with delays of several seconds before updating. They coincide with the time the ASCOM driver was failing but the ZWO one recovers, if someone else has similar issues try native drivers everywhere!!

Might have found something! If I set PHD2 to use the ZWO native driver and Nebulosity to use the ZWO driver it seems to coexist better, the ZWO ASCOM driver is the one that is troublesome (on either end)

Hi all, I'm having some challenges! I have been using an ASI 1200mm Mini for some time as a guide camera and it works well. I have just bought an ASI 1600mm and it works well too. Together, however, they suck! I found a lot of people having a lot of issues too but I haven't been able to find a solution. It seems that when both cameras are trying to image it will fail (either the 120mm in PHD2 does a reconnect or, worse, the download of a picture from the 1600mm in Nebulosity just hangs and doesn't recover). It is easy to reproduce the issue by running PHD2 with a 1 second duration and taking a series of 20 exposures at 1 second in Nebulosity. Things I have tried: 1. Latest versions of PHD/Nebulosity 2. Latest drivers (Ascom and ZWO) 3. USB 2 and USB 3 port test 4. Running Ascom(1) and Ascom(2) as well as ZWO native's driver with ASCOM 5. Various USB speeds, right down to 50 on the 1600 I am running a Startech powered hub which is on an Ethernet link 20 metres away and is stable and reliable so this is specific to the two ZWO cameras. Any ideas?!

OK great, thanks again for the insight, I'll continue to play around with bias but very carefully reviewing what effect it has. Again, appreciate the headstart in finding my feet with the new toy

I couldn't get over the difference so I just double checked, I must have saved some PI processing in the old picture. There is almost no difference with/without bias frames, a very slight contrast improvement is all I see

Very interesting, I just re-ran that 1 minute sub through with the single dark but no bias and it has a dramatic effect for sure, the contrast is much worse without bias but there is a noticeable increase in noise, this is the pic with then without bias:

Ah thank you, not sure what that adds beyond the darks and bias? I just stretched the master bias and it's the cleanest I've ever had, I don't know what issues people have with them normally? Grey outline is pixinsight window and the grey square is the bias

Oh really, I've always taken bias previously so didn't think twice. I have no idea what a dark-flat is but I guess I'll get searching now. The darks are definitely showing some glowing around the edges:

I can't get over how good this is, below is a single 5 minute sub crudely converted to red with 1 dark frame and some bias:

Great stuff, many thanks for that input, appreciated

My 'new' (to me) camera arrived today and I am very pleased indeed! It looks to be in mint condition and was a bargain at £750 with a dew heater and next day delivery thrown in thanks to a very kind seller. Running at 27% the TEC sat at -10 degrees with ambient of around 5 so it is very capable of cooling My guiding was only around 0.8 arc-seconds which is way above the 0.53" I think I need with the 1600. Even with that (and the clouds) I am bowled over by the performance. I am using unity gain (139) and an offset of 15 to get me started - if anyone has any thoughts on this please chime in! I finally have stars that are dots not blobs! The Atik 314 I have been using was a great entry into narrowband but with my 1,500mm focal length on the 300PDS it really was pushing it. This is a much better match with an FOV I can actually use! I ran a quick sub of NGC281 (Pacman) in Ha just to compare old and new and I'm very pleased with the result. t will be a while before a proper pic can be done but this is a very positive start. So here are the pictures, first a 2x2 binning 10 minute sub from the Atik (cropped heavily). You can see I have drift and blobby stars but a reasonable bok globule from a single sub Next, a 5 minute sub with 1x1 binning (so effectively 1/4 duration) from the ZWO: Obviously a bit more noise but blimey is that a step forward! I think I can seriously look at 5 minute 1x1 subs and certainly 10 minute 1x1 Here's a 5 and 10 minute sub in Ha (full field of view) And this was the fov I was playing with before: Lots to play with still but for some first light I am very very happy indeed!

What you are describing is definitely going to be easier in vba, if you do get stuck at all (even getting started) just ping me a message with what you want to do and I'll send you back some code

I'll keep an eye out for the 'any resident VBA wizards' thread

Yes agreed, you're getting into stuff that is possible but very difficult without VBA and incredibly easy with it

Great, well done and hope it all works well

I have never tried competitive editing before but I guess lockdown has us all doing things we normally woudln't! Mine was a combination of PI and PS, the workflow was very dynamic but was something like: - DBE for each of the HOS for RGB. - Levels and curves stretch (lots of little stretches) to try and stop the big star blowing out too much - Mini stretch used as a luminosity mask to pull things back in - Selective colour adjustment of all colours suiting to taste - Star mask and start reduction back in PI - More levels and curves and some colour balance - A little bit of ACDNR and Dodge and Burn - Brightness and Contrast tweaks Then I went round in circles for an hour or so changing colours and changing back again, eventually settled on this but if history is anything to go by I will want to do it completely differently tomorrow!

The bit it isn't liking appears to be the if statement referencing the array formula, if you take out: =IF(('Sidereal times'!$B$3:$B$26-Catalogue!K2)<0,('Sidereal times'!$B$3:$B$26-Catalogue!K2)+360,('Sidereal times'!$B$3:$B$26-Catalogue!K2)) And put it in a cell (CTRL+Shift+Enter) Then reference it with your original formula: =MAX(DEGREES(ASIN(SIN(RADIANS(P2))*SIN(RADIANS(Variables!B3))+COS(RADIANS(P2))*COS(RADIANS(Variables!B3))*COS(RADIANS( !!!!Cell location!!!! ))))) It should work

I can't recreate the issue, any chance you could upload the sheet in question?

That's a nice idea for a sheet I tend to find when I'm entering a formula like you had in the original post that I can boil it down to a couple of simple (and usually hidden) columns so hopefully that workaround will do the trick VBA is easy if you're familiar with coding, it's slightly daunting if you aren't. It is definitely worth a look though if you're getting to the advanced use of Excel you are approaching A blind example of some VBA code that could get you started if you go down that route: Option Explicit Const OBJECT_NAME_COLUMN As Integer = 3 Const OBJECT_SIZE_COLUMN As Integer = 3 Const FOV1_ROW As Integer = 1 Const FOV1_COL As Integer = 3 Private Sub CommandButton1_Click() Dim RowCounter As Integer Dim ObjectSize As Double 'Start from row 1 on sheet 1 RowCounter = 1 Do 'As long as the target info is present (this should only happen if the first row was empty) If Sheet1.Cells(RowCounter, OBJECT_NAME_COLUMN) <> "" Then 'Extract the size of the object Size = Sheet1.Cells(RowCounter, OBJECT_SIZE_COLUMN) If (Size < Sheet2.Cells(FOV1_ROW, FOV2_COL)) Then 'Yay it works for this FOV End If End If 'Move to the next row RowCounter = RowCounter + 1 'Keep going until we run out of data Loop Until (Sheet1.Cells(RowCounter, OBJECT_NAME_COLUMN) = "") End Sub

It would be easier with the sheet if you can attach it? Maybe a simpler way of solving it would be to put your TRUE/FALSE as a column in sheet 1, it would be easy to have an if statement referencing Sheet2!$D$4 and Sheet2!$D$5 which gives your true/false and then a vlookup would be simple VBA is also an easy way to solve this