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Dawson
Participant6 and 1 are not dissimilar in form, which should give you an idea of where 6 resides in the overall scheme of things.
7, I think the clue is the initial plateaux phase of the plot.
8 I think is just difficult!
Sorry.
Dawson
ParticipantThank you.
Thanks all. A non-astronomy friend is going to lend me something to try out, so I will report back. I am surprised the flat bed scanners (I have one) would have sufficient resolving power to convert a 35mm slide into a reasonable quality image, this may be something I could try with my own scanner.
Thanks all again.
James
25 February 2019 at 8:28 am in reply to: Historical Section newsletter for spring 2019 just out #580752Dawson
ParticipantA great newsletter as always.
Was interesting to read about Firsoff and his climbing/walking.
James
Dawson
ParticipantI did the star count last night and could count 12 stars from my back garden; 10 were easy to see, 2 were with averted vision. Will be interested to see the final national results.
James
Dawson
ParticipantLots of ideas above. I think this book is good as it shows you what features are visible throughout the lunar month. Secondhand copies can be sources online for under £10.
Dawson
ParticipantExcellent.
I thoroughly enjoyed it. Best of both worlds; I got to hear the talks and stay away from the stinking capital. Well done all involved; I too watched on you tube. I think it worked well for 3 hours or so; I’m not sure I would have sat and listened to a full day. I especially enjoyed the SkyNotes, a very entertaining and informative edition; just far too much on variable stars 😉
James
Dawson
ParticipantExcellent.
Great to be able to see the talks from home.
Might be useful if the slideshow of images playing at present were to have some text saying “we are having our coffee break, the video feed will return at about 16:15” or the like.
Great stuff.
James
Dawson
ParticipantThanks Martin. This was 120 x 30seconds, so an hour in total. I’m going to wait until it is higher in the sky and try for 60 second subs, and maybe try without the LP filter. I think the LP filter is also cutting out a good proportion of the cometary photons.
I’ve got an ZWO 224 (colour) but it’s not cooled so I suspect it would be vastly more noisy than my Canon and not significantly more sensitive, but maybe worth trying that too, but I suspect 30 seconds on the ZWO would be VERY noisy.
Food for thought, thank you.
James
Dawson
ParticipantGive up…
Will try again in 10 days when higher in the sky and I can take longer subs. Stack below from DSS trying to focus on the comet and the stars. FoV 5.93 degrees x 3.95 degrees; focal reducer flattener is designed for cropped sensors, not full frame sensors which is why I think there are still some obvious gradient rings from some vignetting despite making some flats.
Video of the comet moving over one hour also available here, but 200MB:
https://www.dropbox.com/s/gvtr6kk4mmoouio/IMG_7940_pipp.avi?dl=0James
Dawson
ParticipantI think the fundamental issue with my data is:
– subs too short, I will try 60 second subs, but not guiding so will have to get the PoleMaster out
– I stupidly shot in JPEG and need ot shoot in RAW
– I think the comet will be better when higher in the sky.
Here is one of my many stacks, where I forgot to identify the comet as a comet and it’s just stacked on the stars!
James
Dawson
ParticipantMore info…
Canon 6D with an IDAS LP filter, on WO Meg 72 FD with WO 0.8 focal reducer; lots of darks and flats too.
Dawson
ParticipantPeter Hadland Davis (born 1918) was the son of Frederick [or Frederic] Hadland Davis (born 1882/3). So that link is confirmed.
Dawson
ParticipantDavid Jackson, the chap behind HiTec electronics and who has links with Ian King used to do these.
Dawson
ParticipantIan, you certainly don’t need a college education or an in-depth understanding of maths to use a computerised telescope. It is something which is much easier to learn from someone else, hands-on, than trying to read a manual though. If you have access to a local club or society I would strongly encourage you to get acquainted with them and get some help. Understanding some basic maths is useful for some aspects of astronomy, for celestial coordinates, working out magnification etc, but you’ll get by fine without it. Having an open mind, patience and a willingness to learn something new is far more important, as some computerised telescopes are not always as intuitive as they could be.
Good luck.
James
Dawson
ParticipantMy 14mm Samyang has some aberration at the edge when the iris is wide open; I’d just assumed this was the common given the enormous field of view and the relative affordability of the lens.
James
Dawson
ParticipantI was there for the BAA Summer Meeting on the Saturday and stayed for the first part of the morning session on Sunday for the spectroscopy talks. Excellent event.
Dawson
ParticipantRoy
Thanks for the message. Yes, it is interesting. I suspect you could conduct some transmission tests to numerically compare the light transmission of the three eyepieces. I guess I could do this with one of my CMOS cameras, but not sure how sensitive it would be to the differences between them and probably difficult to standardise the alignment etc between the light source, eyepiece and sensor. Maybe a project for a rainy month… But we are both very grateful for the Tolles.
As for the broken image, the image appears fine on my browser (Chrome) as the screen shot hopefully shows. The image of the results is hosted on my members page as when I tried to upload it to the forum the forum algorithms resized it to 640×480 and the text was not legible, so I cheated and linked to a higher resolution version allowed by the members pages. There may be a way to get higher resolution images in the forum, as I’ll ask the clever technical guys. If the image preview isn’t showing for you, it may be your browser; maybe try a different browser. Having said that, I’ve just looked on my iPhone and the images doesn’t display there.
Regards
James
Dawson
ParticipantIan,
Welcome.
Yes, there is a lot to get your head around.
I would advise finding a local society to get involved with. They probably hold regular meetings and star gazing events. If you email me your nearest city I can have a look online and see what groups are near by.
I wouldn’t rush to make any decisions about buying equipment or deciding what sort of amateur astronomer you are. Go with the flow as they say.
There are plenty of books to read and magazines and forums [fora].
Learning your way around your own night sky is a great place to start with practical astronomy. The major constellations, and any visible planets. A bog standard pair of binoculars are useful for looking at some of the brighter targets in the sky, such as globular clusters and open clusters and the Andromeda Galaxy. Binoculars are also useful for getting a closer look at the Moon.
If there is a meteor shower coming up, that is always fun to observe, ideally on a sun lounger in a sleeping bag or two!
If you are hands on and like tinkering with either mechanical things or electronics there is so much tinkering to be done with equipment and the like, and again lots of fascinating stuff to read. Or maybe you are so hands on you’d like to build your own telescope.
I enjoy reading. I don’t enjoy getting cold. I have various telescopes but I don’t have a permanent set up, so I don’t use them as often as I should. Many believe an observatory isn’t a luxury for an amateur astronomer, it is an essential tool. I like imaging the planets and the Moon, and showing non-astronomers things through the telescope like planetary nebula or globular clusters. I’m also interested in the history of astronomy, and like reading about the goings on several hundred years ago, as well as from the 19th and 20th centuries.
The BAA Journal has some fascinating content and as a BAA member you can look through past copies of the BAA Journal on the website. The Journal also contains sky notes to help you learn more about the night sky. The members pages are great for looking at things others are up to, and if there are things you want to know more about you can either leave a note on peoples observations, or start a thread on the forum.It will be very exciting for you.
Welcome and enjoy.
James
Dawson
ParticipantCallum,
I had trouble with ” and ‘ but then I try and remember that seconds, are second (2nd) and therefore the magic number is 2 so they are “
James
Dawson
ParticipantGrant,
I use a dew shield with a built in dew strap on my C11. I can’t remember where I got it from, but looking online it seems they cost in the region of £100 now!
No idea about the dual mounting for such big [heavy] scopes, but clearly can be done:
http://www.mikesastro.com/equipment/lx200r/C11vsLX200R.html
James
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