Over the last four or five years we’ve taken an incubator and chicken eggs into the childrens’ school for one of the classes to have in their classroom for the whole of the incubation period and perhaps a couple of weeks after the chicks hatch.
They have to be kept in a pen under a heat lamp until their feathers are well-developed (usually when they’re about six weeks old), but here are some photos of this years chicks on their first weekend in the outside world.
Yes, two more Messier globular clusters to add to the collection. These, M10 and M14, are the last for the time being. I have a few other things I want to try out now.
A change of target for the next imaging session. Having got as much as I felt I could out of M3 and M5 for the time being, I moved on to some new globular clusters. This time M53, M12 and M56.
I think M53 and M56 have much more potential, and it surprised me how relatively “open” M12 appeared compared with the others.
Messiers 3 and 5 have become something of a fixation in my attempts to do some DSO imaging with the 127 Mak, but this night they were joined by the second Messier cluster in Hercules, M92. I think these may be my best so far.
Someone suggested to me that Munsen rings might be a good way to fix my PST to a dovetail. As they looked far more straightforward than having to turn some fittings from solid aluminium I thought I’d give them a try. I managed to find a pair of 54mm brass rings on ebay which though slightly too large in diameter were perfect once I’d lined them with sticky-backed felt. Here’s the end result on the dovetail:
It seems as though sometimes you just can’t keep these people out of your images…
The same details as my previous attempt the day before, but I think these ones are a little better. Focus is sharper, I think, and the colours have come through better.
The night preceeding my M3 and M5 efforts I managed a couple of widefield images of the constellations Bootes and Hercules using just the 450D with the stock 18-55mm lens focused at around 25mm focal length according to the EXIF data, using exposures of 120 seconds. So much easier at such a short focal length 🙂 These are both stacks of 18 frames.
It’s not at all easy to pick out the stars forming the asterisms themselves, with the exception of Arcturus which is pretty difficult to miss.
For larger versions, follow the wide field images link above.
Hot on the heels of my “success” with M13, I decided to have a try at M3 and M5. I suffered the same problems with unusable subs for exactly the same reasons: it’s really pushing the mount too hard to expect the stock dual-axis motors and gearing to allow long exposures at a focal length of 1500mm. These two also suffer from a generous helping of noise thanks to needing to stretch the histogram so much. Again, longer exposures (and more of them) would almost certainly help.
I started with 60 exposures of 45 seconds for each image from the 450D, but dropped around half of them due to trailing. I’m not completely unhappy with them, but I’m not totally stunned either…
Oh, as well as M3 and M5 I also caught the ISS in one frame:
A short while ago I purchased a slightly damaged PST for solar Ha viewing. Not wishing to stump up the price of a Tal 100RS just yet, but wanting to make life somewhat easier for imaging and not being entirely impressed with the prism focuser I cast about for other ideas on how the PST could be made easier to use. One that seemed to come up a few times was to replace the “black box” with an SCT focuser and that seemed like it would be worth a try. The obvious problem is that the SCT focusers use a 2″ 24 tpi thread and the etalon of the PST has an M50x1 thread. I decided I’d sort that out once I’d got all the bits together.
Finding a reasonably-priced SCT focuser proved tricky as all the Skywatcher and Revelation ones appear to be sold out, but I was offered a Revelation one second hand and was pleased to give it a new purpose:
When it arrived I found that the etalon couldn’t really be made to fit the SCT thread and by bodging the two together with an unpleasantly large amount of PTFE tape that the focus point was still sufficiently close to the focuser to mean that making up an additional adapter would have moved the focus point too far inside the focuser. So there was only one thing for it: push my newly-learnt machining skills to the limit and make a replacement fitting for the focuser. Fortunately the Revelation SCT focuser has an SCT fitting that is intended to allow the focuser to be rotated. Undoing the screws meant that would come out. I took some measurements and ordered a nice big chunk of 3.5″ diameter aluminium bar from that ebay.
At this point I should perhaps make a few admissions. I’ve never turned anything this diameter before (I only put hands on a lathe for the first time at the start of this year). I’ve never turned a thread on anything before. And I’m entirely self-taught. If anyone is thinking “recipe for disaster” at this point, I’d not blame them
After a bit of faffing about trying to turn something that was big enough for the chuck to almost foul the topslide, a very fast education on the use of changewheels and thread turning and a good deal of “turning by the seat of one’s pants” I have this evening produced this:
The M50 female thread was cut by turning the lathe by hand using the sweat of the fear of messing up a lot of turning work as lubricant. Once done I fitted it to the focuser:
And now for the moment of truth… fitting the “gold tube”. Perfect:
By now more than one person is probably thinking “Yeah, but what about the eyepiece holder?” Well, I’d read that it could be removed from the “black box” and had the same thread as the holder on a Celestron 1.25″ diagonal. I happened to have one and it works. Unfortunately the Celestron diagonal is a prism and the thread fouls the prism slightly, so I took apart a Skywatcher diagonal.
Turns out it uses the same thread.
And now here’s the entire unit assembled:
Obviously there’s still more to do, like testing it, for a start
I also need to make up some mounting rings for it. I have some more aluminium on order for that. Then it will need a finder which I’ll probably fit to the top of one of the mounting rings. And now I’m not so scared of thread-cutting I’m going to make up a 2″ fitting for the focuser that takes the eyepiece directly without needing a diagonal and I’ll use that for imaging.
