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About sophiecentaur

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  1. How to use my Pentax K lenses

    Philip. I looked around on Modern Astronomy but couldn't find that but it seems to be what I need. The adapter in the picture seems to have a reasonable depth to it, which is certainly necessary because, focussing on the sensor must holding a pk lens in my hand seems to need the back face of the pk lens to be well above the face off the cmos camera. Not surprising as the pk lenses have to work with the SLR mirror between. I now realise my problem. I never bumped into the information that the camera has, in fact, a C mount thread. I was assuming that I would be using the 42mm thread on the actual body of the camera. That's the problem when trying to get into a new subject - so many names and numbers and not too much info to help the beginner. That's where HAS and AGL come in so handy. Anyway, I plan to be at the next HAS meeting so we can chat about it then. There is no rush as I have a lot of things to try before that and not many suitable nights for doing it.
  2. How to use my Pentax K lenses

    Hi. That looks to be just what I need. Have you a reference / model type so that I can try to source that adapter? BTY I am a HAS member too. Perhaps we could what's app about this. Andrew Lyner
  3. How to use my Pentax K lenses

    I just got my new ASI120 CMOS colour camera, basically for guiding and also for a start on planetary imaging. Now I have it (complete with a fisheye lens, thrown into the deal) It struck me that it could be interesting to use my existing Pentax camera lenses with it (as well as my 500mm ED80 OTA and guide scope). I have spent some time searching but all I seem to find is ways of connecting other lenses to my Pentax DSLR. That's the wrong way round. You will all appreciate the possible fear of buying an adapter which works mechanically but has the wrong depth for focussing. The ASI120 has a2" spigot, an internal M42 thread and a M42 / 1.25" T adaptor. I have written to the manufacturers of the camera but I have doubts whether they can actually help me. Has anyone else had a similar problem and solved it without buying stuff that they didn't actually need? I'd really appreciate some pointers.
  4. Data connects for guiding

    OK That implies that you needed a different cable, to connect PC to handset? Was this USB?
  5. Viewing Total Solar Eclipse 2020 on a budget.

    You are a mere slip of a lad. I will be 79 by then. So that's why Argentina / Chile 2020 is so attractive. I guess my best bet will be to try to establish contact with Argentinian Amateur Astronomers and find out what they're planning. There seems to be just one main road running through the 'zone' and I an imagine it will be littered with camper vans and the like. The good news is that a return flight London - Buenos Aires is only about £1k at today's prices. I don't actually need a 'carer' yet but anyone who is interested in joining my solitary expedition could get in touch and we could have preliminary discussions about combining resources / map reading and fighting off bandits.
  6. Viewing Total Solar Eclipse 2020 on a budget.

    Well jell!!
  7. Data connects for guiding

    HAHA - well spotted there. I didn't write what I meant. Durr
  8. Data connects for guiding

    Thanks for the responses. I do not have a camera yet so I am assessing what I will need for data connections. I sussed out that the cables that come in the camera box will do the basic business for me. There are numerous sketch diagrams showing interconnections between PC, camera and possibly synscan. I have tried to reverse-engineer the system in my head to find out what exactly happens (that's my standard approach for all of life). Hence, I want to know what the function of a 'guide' (auto guide?) camera is, over and above a camera and I haven't found a description. How is the processing shared between the camera and the PC and what actual signals are carried by the USB cable? I assume that 'all' the ST4 cable needs to do is to send instructions to the mount motors. But what actually goes on in the camera? Is it the guiding brain?I have read of different guiding algorithms but the camera algorithm may not be adjustable(?). On a separate issue, if I have the two guiding cables connected, is it necessary to use a separate cable from PC to Synscan, for just pointing the scope where I want it? To do that would need a USB / ST4 adaptor, I suppose.
  9. I am in the middle of getting into guiding and I have seen several ways of connecting up the data between PC, camera and mount. The simplest seems to be a usb cable from scope to camera and an ST-4 cable from camera to PC. The ads imply it should be just plug and play that way. What do the other more complicated setups achieve? It seems a lot of trouble to make the ST-4 to USB conversion between PC and steering port of the synscan handset. The interface costs a minimum of £35 afaics.
  10. Viewing Total Solar Eclipse 2020 on a budget.

    Thanks for the replies. Fact is that I am getting older and I can't be sure that I won't be infirm if I wait too long. Sob sob. By 2028, I may have no idea who I am or where I am. lol So I want it to be fairly soon. Patagonia has serious appeal, though. It's well off the beaten track. It's a bit of sods law, really. I missed totality in Paris a few years ago as the family delayed our car trip. I was really grumpy!!! This year in the States just couldn't have worked - etc etc. I may have missed the boat but the consolation is that there are so many fab things to see from my back garden. Lovely shots of the Solar Eclipse, BTW
  11. I was contemplating a once in a lifetime trip to see the Total Eclipse at Christmas time 2020 in South America. Looking at Google hits for tours and cruises for this sort of event, the prices are way too high (like $5k each) for me to contemplate. But I am sure there are cheaper ways to get to see the eclipse and I reckoned that several (many?) SGL members must have travelled to see one or even could be planning for 2020. Is there a budget way to do it that would provide just a little bit more help than booking flights and accommodation yourself? What does the Astronomy Mafia do about it? The 2019 packages are all pretty well booked up but I read that the probability of suitable weather is much higher where and when it happens in 2020. Any opinions on that too?
  12. Polar alignment help?

    On the topic of using polar scope reticles. I have an NEQ6 and i have been using the 'quick' method of polar alignment which involves rotating the RA control until the Dipper image on the reticle is as near as I can get it to the angle of the constellation and then putting polaris right in the tiny bubble on the circle. That has been working fairly well for shortish exposures. It does require fair viz of the dipper as well as of polaris. I have a Ioptron Skytracker which has a different reticle but there is an App to do the sums for you and that gives a picture of the placement of polaris on 'that' circle. That method hangs on accurate levelling of the platform more than the NEQ6 method but is it far more convenient. I tried this last night and the results were not good - star trails were a lot worse over 2 minutes. Rather than try over and over again, I thought I would ask for opinions about whether the ioptron app is actually suitable. It does depend on the two polar scopes both being regular astronomical telescopes (inverting) and, whilst it's obvious that the ioptron scope inverts as I can point it anywhere to check, I don't want to disturb my mount enough to look at a terrestrial object in the day (and my neck doesn't like daytime yoga if it isn't necessary). Can anyone reassure me that the NEQ6 scope is also inverting? If it isn't then that could account for the misalignment. If it is then I will just have to go back and check everything again. PS The way polar alignment is described in some sources is very confusing. It took some while to get what they meant about using the picture and the real constellation and the more mathematical descriptions are even more difficult. It's obvious enough when you have actually 'got it' but those few friendly words which would help always seem to be missing. The Drift method is harder to suss out but the instructions seem easier to follow. Am I just too old for new tricks?
  13. Choosing a 2" filter wheel

    Successful imaging requires filters and a filter wheel seems to me to be pretty essential. The range of prices for a 2" wheel is enormous. I am looking at the bottom end of the range so I will buy a manual wheel. What makes of wheel are the best, mechanically and best to operate? I am sure there must be a lot of personal experience amongst SGL members and I would be very grateful for opinions.
  14. Stacking Solar scopes

    Whew. That was a load of interesting stuff. I think a Quark may be the way for me to go for a start. The filter stacking effect is what I would have expected but i didn't realise the significance of it. Solar viewing really suits a lazy devil like me. A warm, bright, clear afternoon and a small telescope wins over the hope that it's worth while staggering out at midnight with a lump of Newtonian and ten layers of clothing. I could grow to love the sun.
  15. Stacking Solar scopes

    Thanks for the comment. I was beginning to think that myself and there seems to be a ready supply of s/h quarks. Perhaps it's an object that has limited long term appeal. Once you have been really impressed by some really dramatic features, that's more of less it unless you want to make a real study. Otoh, the night sky is full of variety. Of course, there will be people who fall in long term love with it.