[Dawson]

Paul, I know you are after various editions of Norton’s which I look out for, but none so far. I’ll see what else I’ve got.

James

[Dawson]

I’ll be there with a load of secondhand books for sale, so bring your money.

James Dawson
Society for the History of Astronomy

[Dawson]

Our eastward facing camera (UK00AN) from the Nottingham Astronomical Society Observatory detected the flash amongst the clouds and Moonlight; bottom right.

• This reply was modified 5 days, 1 hour ago by Dawson.

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[Dawson]

Yes, apologies for hijacking. It is, I think and important, wider, BAA topic.
James

[Dawson]

Thanks Nick.

Poor Denis! Sorry Denis.

With sufficient website access privileges one can search for all comet observations on the member pages for a given period and download them to a file in one go, along with their metadata file. But I guess you and Denis know this already.

James

[Dawson]

Thanks both. Useful discussion.

I think it is one thing for the BAA to ignore images uploaded to social media, it just seems a loss that the BAA is not archiving images its members have uploaded to their BAA member pages.

People are fundamentally quite lazy, and for someone like me [very lazy] who are not devoted to just one section, the thought of having to research each time the file name requirements of the Jupiter, Saturn, Mars, Lunar, Solar, Comet, Meteor, M&V sections each time to submit an observation to the archive is just a non-starter.

Most of my observations are not very good, but they don’t need to be very good to play a vital role in an archive; they may show a feature was really there and not an artefact, or fill in a gap in a time line… For bog standard BAA members like me, there are few [if any] personal benefits from going to all the additional effort to submit to the Section archives when my observation is already on my member page for others to look at and comment on; the only one missing out on my observation not being in the archive is the BAA.

I note neither of you have said it would be impossible to automate the process whereby an observation uploaded to the member pages be prepared in the background for consideration of acceptance into the relevant archive, at the sections discretion. It seems a shame that this is not an aspiration. It cannot be beyond the wit of man, nor outside the budget of the BAA. Maybe it is just not important, I don’t know.

It would be interesting to know what proportion of member page observations / images are in the relevant section archives.

Thanks again both, and thanks to all the various section officers who are the backbone of BAA; none of this is meant as a moan at any of you.

James

[Dawson]

I emailed Lunt to ask them. I’ve had a very helpful reply. The summary is:

“You cannot simply take a pressure-tuned etalon from one 60 mm and insert it into a tilt-tuned 60 mm — they are not plug-and-play. If you want pressure tuning, the safe path is a factory retrofit by Lunt, or purchasing a PT model outright.”

It is all to do with spacing, and alignment.

James

[Dawson]

It is a missed opportunity that the member observation database doesn’t align with the various section archives. A member uploading, say a comet observation, could be requested to enter certain metadata to accompany their observation aligned with the comet section archive; an observation of the Sun may request different metadata aligned with the Solar Section archives; a Moon observation request metadata aligned with the Lunar Section Archive… I can see why section directors or section officers don’t want additional jobs and assume important observations will be sent to them for archiving, but I suspect there are plenty of nice and important observations on the member pages which are not in the section archives as members don’t know the importance of submitting them separately to the Section Directors, or can’t be bothered having to seemingly submit things twice.

I’m not tech-savvy enough to know how difficult or not it would be, but it would be advantageous to all if observations submitted to members’ pages could more easily be entered into the specific section archives.

We all appreciate the work of the [unpaid] Section Directors and their officers.

James

[Dawson]

Thank you both. I have not been clear, sorry, I’d had two glasses of vino! I agree, a flat field calibration frame is definitely helpful for lunar imaging.

I meant should I use a field flattener, to project a flatter image on the chip when taking video for stacking of the Moon? Or again does the stacking process negate the need?

James

[Dawson]

Ian,

I’ve looked at this and it seems the max file size limit has reverted to 2MB for the time being. I’ll let the web ops team know as something needs tweaking in PHP behind the scenes.

If you reduce the size of your images to less than 2MB, it will upload.

James

• This reply was modified 2 months, 1 week ago by Dawson.

[Dawson]

What is the file type? Email me the file; I’ll send you a message.
James

[Dawson]

Thanks all. I had done extensive reading but with my limited knowledge and comprehension of such matters it was impossible to just get an answer in kg. I’m grateful to Nick for coming up with 750kg, which puts my mind at ease, especially as there are four bolts, and as pointed out the aluminium of the dovetail would likely fail first. Paul, I was worried more about shearing across the bolt than longitudinal force and stripping the threads. It was interesting reading about it all though, and I had no idea it was so involved and different thread counts present different shearing capabilities.

Thanks all!

James

[Dawson]

Brendan,

That is really helpful, and gives me hope!

I already screw the camera directly onto the diagonal, but like you the 1.25″ nose piece on the diagonal needs to be pulled out of the focuser to achieve focus, and I wonder if that is where some tilt is being introduced. I will explore, and I have a much longer 1.25″ nose which may help.

All good advice, I am very grateful.

James

[Dawson]

All online sources point to Borthwick and over 1m3 of material. It may be worth a trip to inspect it all.

Have you seen this: https://archive.org/details/in.ernet.dli.2015.165833/page/n57/mode/1up

Several entries in the British Library Catalogue and in Kew’s National Archives so worth looking there if you’ve not already.

And lots of items listed on WorldCat.

And this item in York Archives: https://catalogue.exploreyork.org.uk/client/en_GB/default/search/detailnonmodal/ent:$002f$002fSD_ILS$002f0$002fSD_ILS:781724/one?qu=Cooke%2C+Troughton+and+Simms+Ltd.&dt=list&h=0

And this in the RAS Library: https://royast.cirqahosting.com/HeritageScripts/Hapi.dll/retrieve2?SetID=3548FC96-A89E-472D-B5C3-A99C93BF2149&searchterm=Troughton&Fields=%40&Media=&SearchPrecision=20&SortOrder=0&Offset=3&Direction=%2E&Dispfmt=F&Dispfmt_b=B27&Dispfmt_f=F00&DataSetName=LIVEDATA

Good luck finding what you are after.

[Dawson]

What a tremendous publication Nick, well done.

James

[Dawson]

Thanks Paul, unfortunately one needs a password to access the publication.
James

[Dawson]

I had a hunt online to try and work out what the sensor was in the camera, but to no avail. Hopefully someone else will be able to track down the sensor then it should be easier to find the QE… maybe.

James

[Dawson]

Gary, I think you’ve nailed it. With the eye of faith I can see an inner circular halo in Sue’s photo. Looking in Stellarium the Sun would have been 52.5 degrees above the horizon. I’ve made an animated gif to show roughly where I think the true solar halo is:

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[Dawson]

Chris Hooker emailed about something else and mentioned this. He strongly suggest I try some flats. I’ve found this video so will try some form of cereal bag flats later in the week; I probably won’t use a cereal bag, but something along those lines.

https://youtu.be/M7rSOXWQDZM?si=A6BESGiqf-UoXE5V

Thanks for the replies. I am feeling hopeful again.

James

[Dawson]

Paul, I’m pleased I’m not the only nutter who likes collections like this 🙂 Are there any editions you are missing as I will rummage through the piles of books I have in my garage.

James

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