Success with libgphoto2!

Posted on August 29, 2019 by james

Since the last release of oacapture I’ve mostly been working on oalive, an EAA-type application that will share a large amount of code with oacapture. One of the new things I wanted to do with this was to add support for DSLRs — initially Canon, but I’m hopeful that some Nikon and Sony cameras might work too, as I have further plans once I have DSLRs working. This isn’t particularly straightforward as there’s no direct support for this sort of thing from Canon on Linux (and I assume MacOS). However, there is an interface library that has been reverse-engineered (though isn’t desperately well documented unfortunately), so I’ve started getting my head into that.

For the first time tonight I have actually been able to connect from my Mint 19 desktop to my wife’s 1100D (my 450D is in the observatory and she’s not using hers 🙂 set the exposure time, ISO setting and so on, grab an image (a small part of my 3d printer through the nifty fifty lens, as it happens) and display it on-screen. Feeling quite chuffed with myself now.

Posted in Astroimaging, Astronomy, Computing, Linux | Tagged , | Leave a comment

Rassin’ frassin’ satellites!

Posted on August 29, 2019 by james

All astroimagers know they can be a pain, but was there really any need for this on the first sub of an imaging run?

Posted in Astroimaging, Astronomy | Tagged | Leave a comment

Swimming, 27th August 2019

Posted on August 29, 2019 by james

Eeek! The moment I got into the pool today, I discovered that it was ridiculously warm. There was no chance of swimming a proper set, so I just got on with what I could. A quite unpleasant swim all round, unfortunately 🙁

USRPT distance this year: 172,900m
Total distance this year: 222,900m

Posted in Swimming | Tagged | Leave a comment

A couple of galaxies

Posted on August 29, 2019 by james

A couple more images from the Photoline 72 and ASI174MM last night. No filters, as for the earlier image of the Iris. M51 is 30 minutes of 90s subs, stacked, stretched and cropped, but no darks. Looking at the full frame it’s quite clear darks are required, but actually I’m not unhappy with it. It’s also clear that this one needs a fair bit more focal length. The Triangulum is also 30 minutes, but 300s subs this time, and includes darks. Needs greater sub length I think.

Posted in Astroimaging, Astronomy | Tagged , , , , , , , | Leave a comment

A quick snap of Caldwell 4, The Iris Nebula

Posted on August 29, 2019 by james

Whilst the 80ED was working ok M27 last night, I had a bit of a play with the Photoline 72 and ASI174MM. This is 75 minutes of 300 second subs. No filters as I only have one set, but I did take darks for this one. What’s intriguing me is the apparent diffraction spike on a single star to the bottom left. I haven’t worked that one out at all yet.

I have the TSRED 279(?) reducer/flattener for this OTA, and I think ideally it needs it. The frame is slightly cropped to remove the edge artefacts from stacking, but the stars close to the edge definitely look a little stretched to me.

Posted in Astroimaging, Astronomy | Tagged , , | Leave a comment

Start of a new M27

Posted on August 29, 2019 by james

Other than a couple of weeks back as my first test from the new observatory, I last imaged this six years ago. It’s one of my favourites, so an obvious choice to revisit as I’m getting everything together again and ironing out the little niggles. Also trying to remember how to make everything work again, like merging the LRGB stacks together into a single image in PS.

But for the time being, here’s my luminance frame. 110 minutes of 5 minute subs from my 80ED (without reducer/flattener) and 314L+, stacked, stretched and cropped.

I’m not unhappy with it, though I think I need longer subs and more focal length (I think last time I used my 127 Mak). I’m not sure if I should pull the blacks down a bit to get a bit more contrast. But for now I shall go back to scratching my head at Photoshop.

Posted in Astroimaging, Astronomy | Tagged | Leave a comment

Waning Moon, 26th August 2019

Posted on August 29, 2019 by james

I took 100 subs (1/500th @ ISO800) for this image at the end of quite a long night last night. The seeing had been excellent, but I’m not really happy with the outcome here. I think perhaps the DSLR doesn’t cope very well on images which are mostly black and then a small amount of very bright illumination. Preprocessed with PIPP, 40% stacked in AS!3, wavelets in Registax 6 and PS for the final tinkering.

I think it could be time for a change of technique for full disc lunar imaging. Perhaps switch to my ASI174MM and create mosaics or drop the focal length a little. Then I could use the DSLR for wide field instead. Needs a bit of thinking about.

Posted in Astroimaging, Astronomy | Tagged | Leave a comment

Waning Moon, 24th August 2019

Posted on August 29, 2019 by james

Another clear night, another moonshot…

Pleased with this one. Copernicus seems to have come out well and there are plenty of hints of high peaks beyond the terminator. Lack of sleep means I can’t recall the exact circumstances at the time of imaging, however 😀 It would have been in the small hours of Friday morning, I think pretty much the last thing I did before stopping for the night.

40 of 100 frames of 1/500th @ ISO800, Canon 450D and 127Mak. Preprocessed with PIPP, stacked in AS!3, wavelets in Registax 6 and final tweaking in PS.

Posted in Astroimaging, Astronomy | Tagged | Leave a comment

Swimming, 23rd August 2019

Posted on August 29, 2019 by james

Last swim of the week, and a new target time:

  • 400m f/c warm-up
  • 24 x 50m f/c, target time 49s, turnaround 75s
  • 200m swim down

I first failed on rep sixteen for this set, and finished with one additional failure. Hopefully next time will be better. My “fast fifty” was a mere 0.06s slower than yesterday, so I’m not unhappy with that.

USRPT distance this year: 172,900m
Total distance this year: 221,100m

Posted in Swimming | Tagged , | Leave a comment

Waning Moon, 23rd August 2019

Posted on August 29, 2019 by james

I’m such a martyr, I really am 😀

It was mostly cloudy last night so I’d abandoned all hope of imaging and got into some development work on oacapture/oalive. Time passed quickly, as it does, and before I knew it 2am had arrived. As I walked through the house to go upstairs to bed I looked out of the window and could see the sky clearing and the Moon in view. So, quick change into warmer clothes, open up the observatory, wait for the cloud to clear properly and get imaging. What else?

I did get caught by a bit more cloud halfway through the run, but that soon cleared and I had another go.

For processing I took the best 100 frames of 1/500th at ISO800 as ranked by PIPP, stacked them in AS!3 (which seems to have done something strange to the framing), used wavelets in Registax 6 and had a final tinker in PS.

I quite like the way the peaks of the Appenines show up way beyond the terminator, and the nice line of large craters along the terminator to the south.

Posted in Astroimaging, Astronomy | Tagged | Leave a comment