Oops! I've discovered a new way to screw up an imaging session

[old_eyes]

 

It seems to me that the hobby of astrophotography requires you to learn through bitter experience every possible way things can go wrong so as to be able to guard against them in future.

So I now have a new one to add to my list.

Saturday and Sunday nights were clear here in North Wales, if bitterly cold (-5C early Monday morning). Since I don’t often get clear skies this was a chance to gather some data. I am currently developing a new (for me) control and data capture system to go with my new QHY168C camera. This really needs a USB 3 connection, and as my ancient laptop does not possess such modern accessories, I needed a solution. At the same time I was frustrated by the tangle of long cables from the rig to the laptop, so I thought I would try one of these rig mounted mini-PCs. I bought a Minix computer with one USB 3 and three USB 2 ports, wi-fi, a full copy of Windows 10 and a slot for a micro-SD card for additional storage.

My main control and acquisition software was APT with PHD2 and I remotely accessed and controlled the computer from desktop or iPad over wi-fi.

I had tested all the components out with some short runs, and had everything working more or less OK. Saturday was tests and discovering that really low temperatures and high humidity can overwhelm the dew-heater, blurring the pictures somewhat.

Sunday looked great and armed with a hot air heater for emergency treatment I was out and operational by 7pm. Guiding was pretty good (at least for me!) and with M31 being high in the sky it seemed an obvious target. First 20 frames went fine. Then the wife said “Do you want to come in and see that programme we have been following?”. Since it was very cold with frost forming on every available surface, I thought – why not? So I checked the optics and gave them a blast of heat to get rid of any dew, set a couple of hours image collection run going, and went inside.

Relaxing in front of the television, I was able to be sociable and keep a discreet eye on my imaging run from my iPad, checking that nothing was going berserk in the guiding and that the images looked OK.

Splendid!

Has anyone spotted the thing I wasn’t checking yet?

Yes – for some reason the Minix lost contact with the micro-SD card and all my lovely subs were being stored – nowhere.

By the time I had spotted this, taken out the card and checked it on my desktop, hunted throughout the Minix SSD drive in the hope that the subs had been stored somewhere, rebooted the Minix and got everything back together again, M31 was sinking into the murky and misty depths below 30 degrees and the battery was giving up because I was caning it with the dew-heaters turned up full.

Sigh!

With my luck and the forecasted gloom, it will be weeks before I get another chance. Still, another thing to add to my checklist. Will I live long enough to be ready for everything that can go wrong? I doubt it.

The moral of this story – do not believe that data is being captured unless you can actually see the subs on your storage device, and copy them somewhere else for safety as soon as possible.

[MarsG76]

That's terrible... I mean the way you wrote it has a bit of dark humor to it, but its horrible... especially now that it'll be ages before you can have another go....

My question is, didn't you have to read off the SD Card to see your framing as you were setting up to start your imaging?

When I frame up I capture 2-30 sec highest gain test shots and adjust the framing, so that confirms the working state of the recording media.

 

[carastro]

Oh dear, how very annoying, so they weren't to be found anywhere?

I could quite easily do that with Artemis because if you don't tick the box the images download but don't save anywhere.  

Having said that though I do check my download file throughout an imaging run remotely, so the worst I am likely to lose is the first image before I realise.

Carole 

[old_eyes]

You are right, but I had already captured 20 frames and the last 'preview' in APT looked fine and the target hadn't moved, so I just started another run with more subs. Like I said, I should have kept an eye on image files building up on the card as well as checking the guiding in PHD2 and the incoming images in APT. Apparently APT does not read the previews off the storage medium, but keeps the latest in working memory as it is received from the camera.

I did not know that was how APT worked and I got burned. But I am philosophical. My mistake and I have learned something.

The framing I usually do with Live View and if required the framing mask facility in APT, so I am just nudging things around until I am happy.

[old_eyes]

6 minutes ago, carastro said:

Oh dear, how very annoying, so they weren't to be found anywhere?

I could quite easily do that with Artemis because if you don't tick the box the images download but don't save anywhere.  

Having said that though I do check my download file throughout an imaging run remotely, so the worst I am likely to lose is the first image before I realise.

Carole 

That's what I will do in the future. If we are lucky we live and learn. I have been caught out by the Artemis 'feature' before so if I am using that I always make sure the box is ticked, but it had not occurred to me that a PC could just forget a removable storage device without provocation.

[Gina]

I've done something very similar - a whole night's run of apparently great images - all but the first few lost!!  So I feel your frustration.  I have had many other frustrations mostly with gear failing just after starting an imaging run.  It's amazing that I have captured anything really!

[old_eyes]

11 hours ago, Gina said:

I've done something very similar - a whole night's run of apparently great images - all but the first few lost!!  So I feel your frustration.  I have had many other frustrations mostly with gear failing just after starting an imaging run.  It's amazing that I have captured anything really!

Why do we do it to ourselves? I suppose because when it works it’s great, but I understand the concerned looks of friends and family as they ask “why did you take up a hobby that is so hard and so frustrating?”. I will probably never be really successful at this as I lack the necessary relentless focus and sheer bloody mindedness required, but my time out under the stars (with owls and foxes as a soundtrack) is magical and any images I do manage to produce give me immense pleasure.

[Astro Imp]

36 minutes ago, old_eyes said:

any images I do manage to produce give me immense pleasure.

And that's why you torture yourself.

Good luck next time.

[Gina]

Absolutely right!

[Anne S]

I spent a few hours capturing M108 only to find that I’ve managed to miss the galaxy after platesolving. And Maxim swears blind that the scope was pointing in the right place!

Anne

[old_eyes]

1 hour ago, Anne S said:

I spent a few hours capturing M108 only to find that I’ve managed to miss the galaxy after platesolving. And Maxim swears blind that the scope was pointing in the right place!

Anne

Ouch!

I remember @ollypenrice telling me that every additional piece of hardware, every additional cable and every additional piece of software had the potential to derail your efforts. Plus the challenge of working out what is misbehaving rises dramatically with the number of entities.

As the aphorism says - everything should be made as simple as possible, but not simpler.

Plate solving is next on my list to master, but I will try not to believe it too easily. Suspect everything seems to be the best rule!

[Anne S]

5 hours ago, old_eyes said:

Ouch!

I remember @ollypenrice telling me that every additional piece of hardware, every additional cable and every additional piece of software had the potential to derail your efforts. Plus the challenge of working out what is misbehaving rises dramatically with the number of entities.

As the aphorism says - everything should be made as simple as possible, but not simpler.

Plate solving is next on my list to master, but I will try not to believe it too easily. Suspect everything seems to be the best rule!

I wouldn’t have minded so much if the laptop hadn’t crashed after an update the night before and guiding wasn’t very good then.  I’m trying the Owl next time, at least that’s brighter and I should be able to check it’s on the chip properly.

[tomato]

Here’s another one I’ve done repeatedly, leaving the imaged binned after find and focus, then taking subs.

My wife now repeats the mantra “Remember the binning!” every time I go out the door to set up.

[old_eyes]

1 hour ago, tomato said:

Here’s another one I’ve done repeatedly, leaving the imaged binned after find and focus, then taking subs.

My wife now repeats the mantra “Remember the binning!” every time I go out the door to set up.

Ah yes, that's another mistake I have made. Goodness me the checklist gets pretty long

[tooth_dr]

I took a whole set of calibration images a few days ago and they all saved as JPEG not raw. Not as bad as messing up the lights mind you but a minor inconvenience.