smr

1 minute ago, vlaiv said:

You did not include regular darks in your calibration. This is important if you want proper flat calibration.

This way - you are "flattening" - both light signal as well as dark signal that is not removed since dark calibration was not performed. However - dark signal should not be flattened - as it is not subject to optical train and does not vignette or have dust on it (it is not related to light entering the telescope).

Ok, I'll try with Darks on both stacks and see what the result is.

Ok so last night was quite a decent night for imaging, no Moon and the HH is rising in alt. 

I've just done a calibration test with, and without flats.

This image was taken with 3hours exposure time, the first one is just a stack of the Lights, no other calibration frames. It looks pretty good to me, all I have done is a few level adjustments to do some linear stretching.

Light Frames only:

This second image is calibrated this time with Flats and Dark Flats which I have taken this morning (everything in the imaging train stayed the same between last night and this morning). I used the T-Shirt method (doubled over and held taut with an elastic band)

The Target ADU in APT is around 32,000. It does reach this but with a very short exposure (0.12813s) is what it has do to reach the target ADU. I have tried an LED panel and it's the same with that as well, always an extremely short exposure time), this is also calibrated with Dark Flats. As you can see the flats aren't calibrating the image properly at all. Any ideas as to why? I'm wondering if I even need bother take flats - I can't see any obvious gradient problems or vignette in the first image or dust motes.

The same processing has been done to both, a few linear level adjustments and one gradient exterminator run on each (medium and low) balanced background, inverted with a lasso over the middle of the image.

Light Frames, Flats and Dark Flats

 

I just leave it set to 50.

3 hours ago, CloudMagnet said:

I dont think it would be scope optics if you said on other nights your stars were round, what image scale are you shooting at? If your guide performance in arc seconds per pixel is higher than your image scale, then you will have issues with stars.

I would also look at the SNR of your guidestar, around 20 is quite low, a good way of increasing this is to make sure your guide camera is operating at 16bit rather than 8bit- you can change this on the"connect equipment" page on PHD2, i think its a tiny box next to the connect icon for your camera. You can also turn on 2x2 noise reduction on the camera tab in the advanced settings. You may need to change your gain settings but it should help improve SNR. in turn, that can help your guiding.

Another option could be camera tilt, making sure the camera is fully fixed and is level with your focus tube might play a part as well.

I'm not sure what imaging scale I'm shooting at, how would I know that? I didn't know about the 16bit thing, will have a look at that, thanks.

Here's a gif I made of the first 10 subs from the imaging session before it, this was on the 17th, where to me at least I thought the stars looked ok. So if they looked ok on this night, it would rule out flexure etc.?

22 minutes ago, CloudMagnet said:

If all the stars in the image are pointing in the same direction, then I would first blame the wind. If you had coma then you would see the stars pointing in different directions, towards the center of the image so can rule that out.

You could also check against your guiding performance, wind usually shows as a sudden spike, like a dither. So if you can see big spikes in the guide graph then most likely wind. Reason why it pushes the stars in one single direction is wind is not random, in a single night, the wind will blow from an particular direction (west for example) so it will naturally push the scope in one direction as well.

Thanks for the reply. Yeah it could be wind, I'm not sure. Not an expert at understanding guiding.

I've had a look at the subs again, this last one is worse - so you can see what I mean, it's particularly bad tonight, usually I get some subs like this but mostly OK.

Here's a screenshot of the guiding...

I'm trying to work out why sometimes, tonight for instance quite a lot, the Stars in my subs are pointing towards the left. If you look at the picture they seem to be slightly elongated and 'pulled' left. I've seen this on other nights. 

There is a bit of a breeze tonight, if that has anything to do with it, but they are always to the left it seems so I'm not sure if that's a factor.

I'm balanced properly.

Interestingly, a night or so ago where there was absolutely no breeze the Stars looked nice and round, if it was wind though, why would they always appear as if they're slightly pointing to the left and a bit elongated, this is the centre of the image, you can see the HH in the top right.

Hi,

I'd love to use my Canon 300mm f/2.8 Lens for Astrophotography. I'm a bit unsure as to what to buy for it to sit in my HEQ5 Saddle.

Has anyone got one and can recommend a suitable dovetail bar. I think I would need two dovetail rings, one on either end of the lens.

I'm going to buy the ASCOM Autofocus adapter for EF Lenses.

I've got 16 hours on this so far. Just having a look at the data, starting to pick up some brown dust which is nice. Any advice on being able to pull the brown dust out a bit without introducing noise. I'm going to buy StarXterminator later on, I tried the demo version and was very impressed with it so that might help stretch the data and give some processing flexibility, this is just a rough process to see what is in the data really.

Right, I've finally fixed my plate solving. For a few days I've had lots of problems and errors trying to plate solve. Sometimes, more often than not it would 'Solve' but when clicking on Goto++ it would time out and not solve on that... I downloaded ASTAP and that would 'Solve' but Goto++ said it didn't return enough Stars - not sure why as how did it solve in the first place? Anyway, after lots of frustration, I've installed 3.88 over the top of 3.92 (I tried 3.92 and it was the same) and after installing 3.88 plate solving worked first time, straight away, target within 1 pixel. Thought this might help if anyone else has plate solving problems after 3.88

Thanks for your help anyway guys, appreciated.

19 minutes ago, scotty38 said:

I cannot tell if ASTAP is being used in both cases but did you install, say, the H17 database with ASTAP?

H18

2 hours ago, Budgie1 said:

Okay, so on the top image you have the exposure set to 20s with gain 100. This will be the settings for the image when you hit the "Shoot" button. This image is being plate solved with no issues?

Normally I would increase the gain on my ASI294MC Pro to 300 for plate solving with an exposure of 10s. This give a nice bright image for plate solving and then I put it back to Unity Gain of 120 in the imaging plan.

In the Point Craft settings, you don't have a default exposure set, so it should default to the same settings you have on the Camera page (20s @ 100 Gain), but I wonder if it is. Unfortunately the log you posted doesn't show an image taken during the GoTo++ phase, so we can't see what exposure has been used. It may be worth adding something in there, like 10 or 20s, then that will always be used by Point Craft, no matter what you have set in the Bulb setting on the Camera tab.

I can't see anything else obvious at this stage, but I would try increasing the gain when plate solving.  

Yep it uses the Camera tab bulb exposure for the plate solving time, usually I have that set to 10 and it's always been fine, I was trying 20s to see if that would work.

The weird thing is, like I say, it does plate solve properly when clicking on 'Solve' - most of the time, but just refused completely to solve when clicking on Goto++ after taking an image and trying to solve it just won't.

In the log you can see this...

When I clicked on 'Solve' for the current image it did so successfully:

2022/01/14 00:13:00 (UT 2022/01/14 00:13:00)    Op    PointCraft: Image solved in 5s.

When clicking on Goto ++ (after selecting the same object in the object list) it fails:

2022/01/14 00:14:23 (UT 2022/01/14 00:14:23)    OpErr    PointCraft: Solving failed. ASTAP returned 'Not enough stars.'

I'm not sure it's anything to do with gain as I've always used Gain 100 since I bought my Camera which was in February and plate solving has always been flawless with that gain, until this week.

Here's an excerpt from the log last night where it shows successfully solving an image, but then not able to solve when clicking on Goto++

2022/01/14 00:12:36 (UT 2022/01/14 00:12:36)    Op    Bulb Exp : Bin(1x1), Gain(100), Offset(N/A), Duration(40") CCD T(2°C)
2022/01/14 00:12:36 (UT 2022/01/14 00:12:36)    DBG    Image Timer
2022/01/14 00:12:36 (UT 2022/01/14 00:12:36)    DBG    CCD_IMAGE_TIMER, Image Ready - false
2022/01/14 00:12:37 (UT 2022/01/14 00:12:37)    DBG    CCD Image Ready
2022/01/14 00:12:37 (UT 2022/01/14 00:12:37)    DBG    CCD Image Ready 2
2022/01/14 00:12:37 (UT 2022/01/14 00:12:37)    DBG    CCD Image Ready3
2022/01/14 00:12:38 (UT 2022/01/14 00:12:38)    DBG    Get BlackLevel -  Exception occurred.
2022/01/14 00:12:38 (UT 2022/01/14 00:12:38)    DBG    Get BlackLevel -  Exception occurred.
2022/01/14 00:12:39 (UT 2022/01/14 00:12:39)    DBG    File saved: C:\APT_Images\CameraCCD_1\2022-01-13\Single__0073_Bin1x1_40s__2C.fit
2022/01/14 00:12:42 (UT 2022/01/14 00:12:42)    DBG    Image Saved
2022/01/14 00:12:42 (UT 2022/01/14 00:12:42)    DBG    FocusCraft - Min:414, Max:65535, bits:16
2022/01/14 00:12:47 (UT 2022/01/14 00:12:47)    Op    FocusCraft called - HFD: 9.76, FWHM: 1.20, Stars: 86, Focuser: 2572
2022/01/14 00:12:47 (UT 2022/01/14 00:12:47)    DBG    CCD Image Ready4
2022/01/14 00:12:47 (UT 2022/01/14 00:12:47)    DBG    ResumeAfterTransferCCD
2022/01/14 00:12:47 (UT 2022/01/14 00:12:47)    DBG    No pause
2022/01/14 00:12:47 (UT 2022/01/14 00:12:47)    Op    Finished Plan - Bulb Shoot
2022/01/14 00:12:55 (UT 2022/01/14 00:12:55)    DBG    PointCraft (ASTAP): Ra 05:41:38, Dec -02:15:33, FOVx 3.06577530, FOVy 1.99941864
2022/01/14 00:13:00 (UT 2022/01/14 00:13:00)    DBG    SC Status - checking for plan triggers
2022/01/14 00:13:00 (UT 2022/01/14 00:13:00)    Op    PointCraft: Image solved in 5s.
2022/01/14 00:13:00 (UT 2022/01/14 00:13:00)    Op    PointCraft: Detected FOV size (arc-minutes) - 182.78 x 122.16; focal length - 441.75mm
2022/01/14 00:13:00 (UT 2022/01/14 00:13:00)    DBG    PointCraft: Found Ra 5.6939783096, Dec -2.2593517303
2022/01/14 00:13:08 (UT 2022/01/14 00:13:08)    Op    Synchronized to the given coordinates.
2022/01/14 00:13:21 (UT 2022/01/14 00:13:21)    Op    Stopping PHD2 Guiding.
2022/01/14 00:13:22 (UT 2022/01/14 00:13:22)    DBG    Slew start detected (1).
2022/01/14 00:13:22 (UT 2022/01/14 00:13:22)    DBG    Slew command to RA/Dec started.
2022/01/14 00:13:22 (UT 2022/01/14 00:13:22)    DBG    Slew move started.
2022/01/14 00:13:22 (UT 2022/01/14 00:13:22)    DBG    Generated coordinates for APT Dithering.
2022/01/14 00:13:22 (UT 2022/01/14 00:13:22)    DBG    PHD2 Guiding Stopped.
2022/01/14 00:13:26 (UT 2022/01/14 00:13:26)    DBG    Slew move finished.
2022/01/14 00:13:31 (UT 2022/01/14 00:13:31)    DBG    Going to change Bin
2022/01/14 00:13:31 (UT 2022/01/14 00:13:31)    DBG    No Binning change
2022/01/14 00:13:31 (UT 2022/01/14 00:13:31)    DBG    Checking Exp
2022/01/14 00:13:31 (UT 2022/01/14 00:13:31)    DBG    No filter change
2022/01/14 00:13:31 (UT 2022/01/14 00:13:31)    DBG    Exposure is starting
2022/01/14 00:13:31 (UT 2022/01/14 00:13:31)    DBG    Gain set with Camera Tab value
2022/01/14 00:13:31 (UT 2022/01/14 00:13:31)    DBG    Get BlackLevel -  Exception occurred.
2022/01/14 00:13:31 (UT 2022/01/14 00:13:31)    DBG    Exposure Started
2022/01/14 00:14:11 (UT 2022/01/14 00:14:11)    DBG    Exposure is ending
2022/01/14 00:14:11 (UT 2022/01/14 00:14:11)    Op    PointCraft Exp : Bin(1x1), Gain(100), Offset(N/A), Duration(40") CCD T(2°C)
2022/01/14 00:14:11 (UT 2022/01/14 00:14:11)    DBG    Image Timer
2022/01/14 00:14:11 (UT 2022/01/14 00:14:11)    DBG    CCD_IMAGE_TIMER, Image Ready - false
2022/01/14 00:14:12 (UT 2022/01/14 00:14:12)    DBG    CCD Image Ready
2022/01/14 00:14:12 (UT 2022/01/14 00:14:12)    DBG    CCD Image Ready 2
2022/01/14 00:14:12 (UT 2022/01/14 00:14:12)    DBG    CCD Image Ready3
2022/01/14 00:14:13 (UT 2022/01/14 00:14:13)    DBG    Get BlackLevel -  Exception occurred.
2022/01/14 00:14:14 (UT 2022/01/14 00:14:14)    DBG    File saved: C:\APT_Images\CameraCCD_1\TemporaryStorage\Focusing_CCD.fit
2022/01/14 00:14:16 (UT 2022/01/14 00:14:16)    DBG    Image Saved
2022/01/14 00:14:16 (UT 2022/01/14 00:14:16)    DBG    CCD Image Ready4
2022/01/14 00:14:16 (UT 2022/01/14 00:14:16)    DBG    ResumeAfterTransferCCD
2022/01/14 00:14:16 (UT 2022/01/14 00:14:16)    DBG    Make a pause
2022/01/14 00:14:23 (UT 2022/01/14 00:14:23)    OpErr    PointCraft: Solving failed. ASTAP returned 'Not enough stars.'
2022/01/14 00:14:23 (UT 2022/01/14 00:14:23)    OpErr    PointCraft Error: Solving failed, will try to make new image after 30s and solve it. Attempt 1.

Camera tab

Plate solve settings..

Choosing an image from last night and solving works as seen below, but if I was imaging, and clicked on Goto++ ASTAP would say could not find enough stars and PS2 would time out

Just to recap as I've just posted this on APT...

Strange problem with plate solving - It's been working fine for over a year or two since I started using plate solving PS2 in APT. The past week it's been really problematic. It's been very temperamental in whether it solves an image or not. Sometimes it will solve when you click on Solve but when you then click on Goto++ to get a more accurate centred plate solve it just endlessly tries solving before timing out. What I noticed, interestingly, is that when I click 'Show Image' it just shows a dark / black frame with no stars, it looks basically like a dark frame. So I'm wondering why this would be, it's (sometimes) fine with the first Solve and image, so why not when I click on 'Goto++' ? I installed ASTAP last night and that is the same thing, it will Solve within seconds, and then clicking on Goto++ it says it could not find enough stars. Weird! I've attached an image, if anyone could have a look (specifically Object Calculator) to see if I've put the settings in right - my scope is 430mm and 2600MC Pro is 3.76 pixels, 23x15mm Sensor dimensions. I'd really appreciate any help, I'm an IT tech so I consider myself quite proficient at troubleshooting, but I've ran out of ideas and the only thing left would be to format and reinstall Windows and all software... unless anyone can help!?

The strange thing is that it does solve with ASTAP when you click Solve, but when I click on Goto++ it doesn't - saying there aren't enough stars. Very strange, it can obviously see enough stars to do the normal 'Solve' but not the Goto++ !! 

Quite infuriating, the only thing left to do is format and reinstall everything I think.

Ah I see it's integrated in APT, I've installed it. I think I can see what you mean in terms of how fast it is but I'm generally having problems with plate solving so even that is failing to detect stars.

I really don't understand what the problem is, seen quite a few errors with PS2 over the last couple of days...

Overflow errors 

Solves, but then when I click on Goto++ it doesn't solve, it just endlessly searches, upon clicking on PS2 and 'Show image' (imagetosolve.fit) the image is just black, like a dark frame, hence why it can't solve. I don't understand the reason behind that.

I've tried it with the image being stretched, without, made sure all the settings are correct - focal length, pixel size, sensor width. 

I've uninstalled and removed everything to do with plate solving - even all sky plate solver, deleted PS2 and APM directories and reinstalled everything, even uninstalled APT and then installed the latest beta ( but I don't think it's a complete uninstallation as all the settings were still there so they must be saved separately to the default installation folder)

The only thing I can think of is formatting my laptop and reinstalling, because if that doesn't fix it nothing will. 

The laptop itself is getting on a bit (i3 CPU, 4GB RAM but it has an SSD I installed in it so it's quick enough) and it has been absolutely fine plate solving for a couple of years now, I've only just started having this problem where I'll need to re-solve mid way through the session and it just sits there trying to solve for ages before timing out for whatever reason. At least I can see one reason why it isn't solving when I click on Goto++ (with the black imagetosolve image) but I don't know why that is.

... or do I even need it to? Will it plate solve for me itself? I don't want to plate solve an image, I need to put in RA and DEC values for the mount to slew to.

Does it work with APT though?

12 hours ago, The Lazy Astronomer said:

As is discussed in the video linked above, the optimum minimal sub length depends on your equipment and sky conditions. 3 minutes is probably in the right ballpark for you with the l-extreme.

In broadband, you'd probably find the optimal minimum sub length drops down to somewhere around 20 seconds, however if 3 minutes is working for you in terms of mount performance, number of images affected by satellite trails, etc. then there's no burning reason to go shorter - just know that you can if you want or need to. 

Thanks, I didn't realise I could go that short without the filter. Shorter would definitely be better as there would surely be more keepers in a stack of 1m subs to 3m subs?

Thanks. Looks like good software.

I've fixed the plate solving problem, in APT under Tools I had the CCD width as 23.5x15.7    - I've changed it to 23x15 and it's working fine. I can't believe I've wasted a couple of hours of imaging, and a couple of hours this morning troubleshooting that!

I've been imaging for several nights on NGC 2023 and at the beginning of each session it's been fine. However, when I come to do a Meridian Flip, and have to plate solve again, it just endlessly searches and then timeout. I've uninstalled PS2 and reinstalled everything including all sky plate solver etc. and checked all parameters (pixel size, focal length, sensor dimensions etc.) Well, doing some testing, I just loaded an image from last night, to see if it would plate solve on NGC 2023 (which is the blue nebulosity near the Horsehead and Flame Nebula - between them), I'm choosing this to centre my fov for framing. Again it wouldn't plate solve on NGC 2023 - so, unable to think of what else could be causing it, I decided to choose the Flame Nebula from the list of objects in the objects browser, and doing that it solved within a few seconds. So why is it that it's very temperamental with plate solving on NGC 2023? Last night I wasted a couple of hours trying to get it to plate solve but it just wasn't having it!

1 hour ago, david_taurus83 said:

Does that camera switch to high gain mode at 100 or at 101?

Not sure it comes with a high gain mode, I think I read that the Altair Camera does, haven't heard anything about a high gain with the 2600MC Pro. 

Re sub length - I've just assumed that as long as the data is off the left hand side of the histogram, ie. not clipping then it doesn't really matter what sub length you choose? Which is why I always shoot at 3 minutes, filter or no filter, as the resulting histogram in APT looks the same, it's off the LHS, not by much, but is off it, and when I stack in DSS the resulting TIFF shows a histogram and data which hasn't been clipped as well. 

Out of curiosity I have just started doing 5 minute subs though, to see if my guiding can handle them and if there's any difference.

Edit - oh yeah I remember reading this a while ago... there is a high gain mode.. When the gain value is 100, the magical HCG high gain mode is turned on, the readout noise is greatly reduced, and the dynamic range is basically unchanged. It is recommended to set the gain to 0 or gain 100 in deep space.. - ZWO

1 hour ago, teoria_del_big_bang said:

Personally with that moon I would add the filter and go for 10 (or longer if guiding is up to it) min subs. 
Regarding angle, before I got my rotator (which is a great help)  if I had to remove camera , or anything in the optics, I would put a small piece of masking tape on somewhere where I could draw a line across the gap between them so I could line them back up when re-assembling.
OK not accurate to seconds but usually got me back to within a degree so minimal cropping required.

Steve 

Thanks Steve

Not sure my guiding is up to 10 mins but will try 5.

Actually just worked out how to install the filter without changing camera rotation. I can unscrew the camera from the 360 rotator so the rotator is still fixed in place. Pop the filter in and then screw it back on. Your post helped inspire that !

Slightly OT but the skies may be clear tonight, and I'm wondering whether I should image with my l enhance filter or not (re the Moon) what would you suggest? It's 80 percent Moon and sort of close to the Horsehead.

The only issue is that I have to unscrew the Camera to add the filter inside the field flattener so when I screw the Camera back on it's going to be at a different angle to the previous sessions. ie. The 6 hour stack was two sessions (with and without filter) hence the differing angles and required cropping.