Some of you may remember that I picked up a Baader 8-24 zoom lens from Astrofest a couple of years ago for £60. It was complete but the mechanism was a bit crunchy and sticking. Eventually it packed up completely. This left me with two choices, abandon it, or to attempt a very complicated and almost impossible rebuild.
Anyone who knows me would guess that I went for the second option!! So, heart in mouth, I went for it
I would immediately stress that, unless you are very technical, or completely mad (like me), **** DO NOT ATTEMPT THIS ****. There are lots of tiny screws, lenses and spacers and plenty of grease.
The problem I found was that there are three rollers/ guides that run in a helical groove. See the screwhead to the left of the 20 in the first picture. If you look at the second picture you can see there is no roller. The screw of that, and the third roller , had sheared. These screws are tiny M1.8 x 4mm screws.
This is where the fun part/ insanity started, as I had to either extract the sheared screws or drill them out with a 1.3mm drill. It wasn’t possible to extract them so I had do some very nervous and careful drilling. This also involved a complete stripdown to clean everything. I mentioned plenty of grease … it was everywhere!!!
I gave everything a good clean and (eventually) got it all back together, and IT WORKED!! Yayyyy . I now have two working zoom lenses
At IAS this year, Paddy Gilliand gave a fantastic talk on picture processing. He showed an example where the original image looks virtually washed out. By careful splitting of the image into different exposures, he managed to recreate something that I think is pretty damn good.
Look at the section on Manual HDR. It looks like a good process, and very effective. The link to the slides is below:-
IAS 2017 V1.2
it was beautifully clear last night so I got this gorgeous lunar shot with my SkyWatcher 102 and the equivalent of a Celestron Neximage ccd camera
Last weekend, Dave Jones, Pete Simkins, Paul Simkin and I went to the Brow Farm campsite near Church Stretton to try out an informal Star Weekend. Heather and Doreen were also there for the Friday night. The second photo shows the view from SE to SW from the higher part of the site
Pete and Paul arrived on Thursday and had quite a good night’s observing. Unfortunately the rest of the weekend was pretty cloudy and rained some of the time. At least my tent didn’t leak this time as it did at Solarsphere.
Saturday brightened up quite a bit and we all got out our solar setups for a while, until hazy cloud made us give up again. At least we all saw a very nice sunspot for a while
On the Friday night, we all met up with Roy and Peter from the Shropshire Astronomy Society and all had a very pleasant meal and a few pints at the local pub. They invited us to go and see a talk by Pete Williamson at their meeting on Saturday night. It was a very interesting evening and the talk was excellent
Brow Farm is potentially a very good venue with minimal light pollution. There is a flat area with electric hook-ups and a hillside with 3 camping pods. There is also a separate field that is usually used by parties. If we wanted to set up a larger gathering it would be ideal as it is flat and has good visibility all round. It also has an empty caravan that could potentially be used as a presentation room/ meeting place if the owner allowed it
The campsite is less than an hour and a half from most of the RAG members and is very cheap, at £6 per head (plus £5 for electric if required) per night
Great weekend in all and I thoroughly enjoyed it
Well, I invented a new type of astrograph. You don’t need a baked bean tin or photo paper
All you need is a glass globe, a south facing conservatory and a wooden window sill….
We were lucky
Well, 3 brave souls ventured forth again to do battle with the dome refurb, and we had quite a productive day reassembling the shutter track and chain rollers. The shutter is back on, albeit the chain drive isn’t re-installed yet
We’re getting there…. slowly
I picked up the rebar ‘skeleton’ this morning so we now have all of the necessary bits to build the pier for the telescope. The ‘skeleton’ is pretty substantial and I could only just pick it up on my own. I have all of the ducting in the garage and I’ll have to see how that all fits together now. The piece you can see on the right is the template that I made for holding the studs in place in until the concrete dries. It’s a piece of plywood I had lying about, which for the last 10 years was actually the platform for the slide in the village playground. We replaced it recently with a new piece. Recycling in action, huh?
I’m seriously considering going to Herstmonceux and/or Astrocamp in September. Does anyone fancy both/ either of them?
http://the-observatory.org/astronomy_festival_2017 – Herstmonceux
http://astrocamp.awesomeastronomy.com/- 23rd – 26th September 2017 Brecon Beacons
Sharing transport is an option
Here’s a nice little timelapse from a few days ago, edited using a free bit of software for windows called Shotcut (https://www.shotcut.org/). It’s a bit like Windows Media player and VLC player but it allows you to export a speeded up video, which is very handy
This one is effectively running at 60fps and was a timelapse recorded on my All Sky Camera with iSpy recording at 1 frame per minute over about 6 hours, although, I’ve cropped this much shorter as it was getting light
It’s quite nice as you can see the Plough moving down the screen, and the after about 20 seconds you’ll see Cassiopeia coming in at the top right near the tree . You can also faintly see the Milky Way moving down the screen after that.
I think for a cheap DIY camera it’s not bad