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jgs001

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Everything posted by jgs001

  1. I've moved this thread to the solar imaging section. Basically, what has been said, and make sure you're very careful. Please don't use filters that are not rated for solar use, as they just do not reject enough of the solar radiation for safety. For a sheet http://www.firstlightoptics.com/solar-filters/baader-astrosolar-safety-film-nd-50.html or a premade http://www.firstlightoptics.com/solar-filters/astrozap-baader-solar-filter.html For camera lenses, a disk of the first sandwiched between a pair of UV filters works nicely, just make sure that the entire clear aperture of the filters are covered.
  2. What's wrong the focuser ? If it's 'sloppy' and loose, then Teflon tape will cure that. It's not a challenge, I tried all sorts with my SLT. Upgrsding my scope from an ST80 to an ED80 caused me enough problems with the SLT. I tried with a mak on my heq5, and the Make was just to slow (f/13) for an SLR. Good luck if you want to give it a try. Sent from my GT-I9300 using Tapatalk
  3. That's pretty much correct... an unmodded camera is less sensitive to infrared (Hydrogen Alpha emissions). Thus images of the likes of M42 tend to be much bluer with an unmodded camera, than with a modded camera. (My M42 image in that thread is an exception, but that's down to the CA filter I was using stripping out the blue). The biggest problem with galaxies, and this is where an SLR becomes less than ideal, they mostly, appear pretty small in the FOV, and the large sensor of an SLR means they appear small in the frame, unless you have a really long focal length. There's no way with an SLT. That doesn't mean you can't get some results on the like of M31 though. So give it a go, just go against the grain and wait until it's low in the east... you can get longer exposures that way.
  4. Jim, you might want to take a look at http://stargazerslounge.com/topic/228101-the-no-eq-dso-challenge/ for examples of what are possible.
  5. You need to set the mirror lockup to enable it, then also set the camera self timer. The effect is, that when the exposure is triggered, the mirror lifts, the self timer activates, and once the self timer has counted down, the shutter opens. Add the couple of seconds that the self timer uses to the exposure plan in ByeOS. As long as the skew in balance is small, that's ok, but make sure that the tail isn't too heavy, and thus puts undue strain on the mount. You may need to shift the scope forwards to counter the excess weight, I don't know how the travelscope is mounted in this case.
  6. Nicely done. Nothing wrong with the little SLT mount for imaging, if you set it up right, and accept the limitations. You want to get the balance right... slightly tail heavy, i.e. the weight biased towards the camera. Not a lot, just enough to keep the gears engaged, or it'll bounce around all over the place. Keep the max exposure time down dependant on where in the sky you're imaging... Low in the east/west is good for up to 2 minutes (well beyond the drive limitations, I was losing 50% subs with 2 minute exposures due to tracking errors), down to 30 seconds, North/South and overhead. I would also suggest using mirror lockup, with the self timer in bulb mode with some form of intervalometer (cheap clones on amazon and ebay can be had for about £12). I used to use an ST80 clone on a NexStar SLT for DSO's, and managed to get the bubble nebula with an unmodded camera.
  7. I was thinking I could setup my astrotrac and use that, and automate a series of captures... but it looks like the clouds are going to roll in around 0800 of course. So will just go manual, and get any shots that might present themselves.
  8. That'll work... I'll be working, so will have to steal moments as and when.. and the S@N guide seems like a plan for that
  9. Why would you need to shoot a frame every 5 to 10 seconds ? Why not every 5 to 10 minutes (the S@N article suggests 10 to 15 minutes apart) ? that's what I'm planning on doing. I'll be using my ED80 on a camera tripod... I can't mount up my HEQ5 in my office, however, a PA using a compass for North, and the Latitude scale on the mount will suffice (you may need to tweak the tracking later on, but if you're using 10 minutes between exposures that's really not a problem). I'll have to shoot through the window... no choice... but may set it up for window cleaning shifts the glass all the way out the way, as it moves the glass out the way. Fit the filter, set the camera to spot metering, and take a meter reading... As I recall, I normally go for about 1 to 2 stops under exposure. I typically colourise my solar images an orange colour. Don't forget to check your solar filter before use to make sure there's no damage, keep your finders covered/removed/with a filter on.
  10. Thanks peeps... Chris do you have any pics ? I'd love to see what they look like... Bet they're fab.
  11. Not done this in quite a long time. But two Fridays in a row. Last week I was shed to help out at my sons scouts, on an astronomical theme. I took along my ST80 and showed them all the moon and Jupiter, there were quite a few wows. And tonight my eldest decided he wanted to look 'up'. So I dug out the ED80. First off a nose around in the binos, M45, lovely... Then got Sirius... Lined up the ED80.. I remembered where my 2 to 1.25 EP adapter was, dropped in the 17mm Hyperion, and studied the Orion Neb for a while... First time I've seen the trap, and understood what I was looking at. I'm sure I could make out a wisp of M43 AMD even a faiby hint of the running man (is that even possible or did I see something because I a) know where it is and expected to see it? Answers on a part card please). He had a good nose to and also saw the trap and M42. Then onto Jupiter... 2 moons, not sure which, I've not looked them up. And with a little care, the equatorial bands, they drew a wow from me eldest. Then with clouds moving in, the moon coming up over the house, and my next parental taxi run coming up, had to finish. Still that was rather enjoyable, and I think he enjoyed it to. I've given him one of my many pairs of binos (bresser 10x50's to use) . Who knows if he gets hooked, maybe we'll get a big dob for the family. Sent from my GT-I9300 using Tapatalk
  12. An AltAz mount is not the ideal tool for imaging, however, if that's what's currently available, it will be able to achieve results, and some excellent ones at that. For someone starting out, we need to provide encouragement, not argue over whether a large Dob would be capable of getting the incredibly faint detail. This is not the place to get into an argument over what is and isn't achievable. Pipnina, having reread your post, it's not clear if you have already purchased the dobsonian scope. If not, then is your main objective visual with the occasional image, or mainly imaging with the occasional visual ? If mainly visual, then if you haven't purchased anything, the Dob is going to be an excellent choice. If mainly imaging, then I'd suggest a rethink, as the Dob is not ideal.
  13. At your price point, I think you'll struggle to get a fold out screen. I suggest taking a look at second hand prices... http://www.mpbphotographic.co.uk/used-equipment/used-digital-slr-cameras/used-canon-digital-slr-cameras/ A 400d is £89, but doesn't have liveview a 450d is £124 and has liveview There are others on there, in the next range up, 30d and 40d, but they are larger and heavier, although the prices are a bit lower. I don't know if they have liveview though.
  14. Yep, that's correct, whenever you lose power for whatever reason, you must start again. Changing the battery mid session would cause a loss of power, and the system will need to be setup again.
  15. With an AltAz mount you can get exposures of between 30 seconds and 2 minutes, depending on where in the sky you're shooting. It's not an ideal option, and certainly not going to produce the results of a decent EQ mount, however, go for it. N/S and through the zenith is the shortest exposure times, whereas low in the east/west is up to 2 minutes, without trailing from field rotation effects. The biggest restriction is actually more like to be the tracking drives. I found my AltAz mount drives suffered from too many defects on the longer exposures, and that keeping the exposures to under 1 minute was the best option. However, even with 40 second exposures, you can achieve results, including capturing the bubble nebula with an unmodded dSLR (ok, I had 132 lights in the stack, it took a very very long time to process). You're only real option would be to test it out and see what you can achieve. Just don't expect to be able to get the real faint detail, as that requires much longer exposures, and you will not be able to achieve those.
  16. I'd be tempted to uninstall and reinstall...Then grab the update from Canon for the 1100d. I had problems trying to use my 450d EOSutils install with my 60d. I can't remember, but the reverse may also have been true.
  17. I've a pair of the Savannah ED 8x56 bino's. They are excellent. There's a little CA to be seen around the edge of the FOV under high contrast conditions, but as I very rarely use the very edges, this is not a problem. I had the opportunity to compare them with some bino's worth more than double the price, and, I wasn't able to see any real differences... not until you get up to the likes of the several thousand pound variety was I able to detect any real improvement. The difference between the Savannah ED's and my normal bino's is like comparing the views between an ST80 and an ED80.
  18. With a short focal length, I was able to get between 1 and 2 minutes... I found the motor drive to be rather temperental, and the drive speed varied with temperature, which made any form of accurate setup challenging. You'll need to rig up some form of polar scope. I attached a finder to the mount for this purpose.
  19. Here's the wiki page for a barn door mount https://en.wikipedia.org/wiki/Barn_door_tracker
  20. A very simple sort of eq mount that uses manual controls to track. Sent from my GT-I9300 using Tapatalk
  21. Thinking about it, you could use the mount as a complex barn door ... Put a dSLR on the top, use a short focal length, and in theory, although you'd need to investigate, you ought to be able to adjust the axis with the slo mo controls, and get a reasonable length exposure (over 30 seconds). That would only need a dSLR and kit lens. If you can pick up something like a Philips SPC900 (although they are getting rarer than hens teeth) one of those is easily modded for astro, and works well for the moon and planets.
  22. Orion will fit nicely in the FOV of a 50mm on an APS-C. This is after a crop, as I used it a wee bit too wide (f/3.2), and the coma around the edges was frankly dire. Orion Widefield As for the CLS with the 18-55... I've read that you can remove... the rear component of the EFS lens (with a hacksaw) and then you won't have the problem. Personally I've not tried it, and don't plan on it anytime soon... although, I may look at picking up one cheap second hand and 'modding' it.
  23. Thanks Olly, that's what I meant by the 'control point'... a very succinctly put description
  24. You have a fair amount of lens flare/internal reflections... the green bits... Did you have a UV filter mounted on the lens ? this can cause this... if so, remove it. The lens is suffering from a fair amount of CA (blue and purple fringing)... I don't know what might have caused the star shapes in the first one... The only thing I can think of for the shapes is something internally may be wrong... Worth trying without any filters before going down that path though.
  25. I think the mount will be the biggest challenge here... I suspect it's a bit light for that scope and dSLR. And without motors I don't think you'll be able to image anything other the moon. The planets will be too small in the FOV, the Moon will be a nice fit though. For Deep Sky, Orion Neb, you must have tracking, the more accurate the better, at any focal lengths longer than really short (at 18mm you're limited to around 25 to 30 second exposures)... a rule of thumb for untracked... exposure time = 400/(focal length)... so for a 50mm... 400/50 = 8 seconds.
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