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About almcl

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    Star Forming

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    Telford, Shropshire
  1. almcl

    Help with whole sky shots

    Have a look here: http://beltoforion.de/article.php?a=untracked_astrophotography&p=camerasettings The much quoted rule of 500 may need to be modified a bit with a crop sensor. If you are handy, a barn door tracker will allow a considerable extension to your imaging time without too serious trailing and doesn't cost much to make.
  2. almcl

    guiding /imaging

    Did you run the guiding assistant? I find the the min move settings need changing from night to night, depending on seeing, where the scope is pointing &c. Another thing to look at is the oscillations in RA and Dec. Ideally these should be similar and small\(ish). If these are very different the bigger one may be giving rise to the 'eggyness'.
  3. almcl

    guiding /imaging

    If I've done the sums correctly, you're imaging at 1.17 arc seconds per pixel and guiding at 5.3 arc seconds per pixel. There are several opinions on what a good ratio between these two might be, one thread over on Cloudy Nights suggested that today's guiding software would easily cope with that, so best advice might be try it and see!
  4. almcl

    EQ5 for Imaging?

    It rather depends on what scope/weight you want to use? I use my belt modified EQ5 with a 200mm Canon lens on my Canon 700D and it does fine. Of late, the average tracking errors (as reported by PHD2) have been around one and a bit arc seconds. As the rig is imaging at 4.5 arc secs per pixel, I am quite happy with this. But if I were using my SW200p (0.85" pp) quite a few subs would have elongated or 'smeared out' stars.
  5. almcl

    Stellarium - weird names after upgrade ??

    Had the same irritating problem until I discovered the 'Use designations for screen labels' button. (See below)
  6. Much good advice given above, so just to add that I started with an EQ5 and a SW200P. Qucikly added the dual axis tracking motors, then guiding, then replaced the motors with an AstroEQ and stepper motors. This last was a game changer as it not only provided much better tracking, but also gave Goto capability. If you are handy and can fabricate the brackets and solder the circuit board, it should be possible for £100 or less. You do need a laptop or similar to run it. The images in my album were almost all taken with this rig, and I still use the EQ5 but with a 200mm f/l length Canon lens on the 700d.
  7. almcl

    Powering a Canon T6i?

    If you google Canon T6i ac adapter, you should find a range of systems/options. Many come with a dummy battery and this can also be powered from an accumulator with a suitable voltage.
  8. almcl

    Powering a Canon T6i?

    USB is 5 volts and the T6i requires 7.4 volts so you need something to step the voltage up (that's what that small black box with the twin leads in the first link does) and, depending on which type of USB socket (1, 2 or 3) you are using, it may not supply enough current for the voltage converter to work. But you can't go straight from a USB port to the dummy battery.
  9. The supplied cable was massive, heavy and inflexible. The only thing supporting the camera's usb socket was a couple (or so) of pretty indifferently soldered connections to the internal printed circuit board. Over time cable flex broke these free and the camera refused to connect.
  10. Ain't that the truth, Louise ? I don't think I'll risk another QHY 5L - it was the large USB connector port which broke on my first one - so possibly look for a full sized ASI 120 (the mini is good and compact and has a the much smaller and easier USB port but is almost £30 more. Not sure how PHD2 will cope with two identical cameras...
  11. Thanks all for the thoughts and suggestions. I do have a spare finder scope which I did use with a QHY 5Liim for a while but moved on to an ST80 and then to the OAG in pursuit of more accurate guiding. This has largely been successful and PHD2 now often reports average total oscillation down around the 0.5" mark, but this does seem to be dependent on a good PA - hence my quest for something better than the results from just the polar scope. When it was on the rig the ST80 was secured by rings to an aluminium bar on top of the SW200P rings. Getting it out of the rings in the dark would be simple enough, not so sure about getting the guide camera back into the OAG and getting the correct focus - even with the Baader click lock... Must admit a second guide cam is a distinct possibility (I could fit it to my EQ5/Canon 200mm EF 2.8 lens rig - which does use a finder scope to guide) but was hoping to avoid the expense... My 'Horizon' looked something like this a couple of years ago (trees have grown more since this image and for street light reasons the mount is usually set up further in, making the western view worse). Green line is meridian, blue is the celestial equator and red are the cardinal points. Agreed an OAG isn't a strict necessity, but it has certainly produced better guiding and, bearing in mind I'm imaging at 0.89", this is quite desirable. A polemaster would certainly be a consideration, but the expense question rears its head (again!) and having read the on-line instructions for it, I was a bit daunted, hence my hope that someone on SGL was using the PHD2 Polar Drift Align successfully and could tell how they did it?
  12. I do still have the guidescope, Dave, but one of the reasons for shifting to an OAG was to loose the almost 5 Kg of extra weight that the guidescope (an ST80) generated. I am quite keen to keep that reduction if possible, but it's certainly something to consider. As well, focusing the guide camera after removal and replacement takes forever at the moment, although a cunning trick in Cartes Du Ciel involving reposition the OAG field of view has simplified that a little.
  13. Does anyone use PHD2's Polar Drift Align? Since moving to an OAG, I can no longer use Sharpcap's excellent PA routine and, lacking an east or west horizon, can't make drift alignment work. So, apart from using the polar scope (which admittedly often gives errors of less than 5') the only thing available is the PHD PDA tool. But there's a problem. The field of view is miniscule (909 mm focal length onto an ASI 120 mini - seldom more than one star available) and the target circle is seldom visible on the screen once things have stabilised and moving the star even a short distance in the indicated direction almost always results in a *bigger* error being reported at the next iteration. Anyone who has got PDA to work care to offer their thoughts or any tips? I have contacted the author of the routine and carefully followed his (very quickly and friendly provided) advice, but so far haven't resolved the problem.
  14. almcl

    Imager looking to view

    My SW 200p came with an EQ5 mount as standard and, I think, still does. For purely visual use this is fine. Over time I added motors, then stepper motors and an AstroEQ and used it for imaging, too, but it was a bit over loaded with a DSLR, ST80 guide scope and so on - still got some good images and it remains in use for my 200mm Canon lens for which it is more than adequate.
  15. You don't see Ursa Major (or Cassiopeia) in the Polar scope field of view but just rotate the axis until they are approximately in the same orientation visually. (If that makes sense?)

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