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datman

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About datman

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    Nottinghamshire
  1. datman

    Deep sky imaging magnification

    Well it would seem I was right, and at least I took the trouble to provide some advice. Criticism alone is easy, constructive feedback takes some thought.
  2. datman

    Deep sky imaging magnification

    Yes Olly you're right, too early and too old is my excuse ;-)
  3. datman

    Deep sky imaging magnification

    Hi You might get a better response if you did a basic proof read on your post. I'm assuming key = sky. You don't mention what other equipment you are using, I've checked your website and see an EQ3-2, Nikon DSLR and a SW150. A 2x barlow/Teleview will double your exposure time so for the Pinwheel maybe 10 minutes @ iso 400/800 IMO the Eq3-2 isn't anything like sturdy enough for this length of exposure, especially since it would need to be guided. Is that why you're not using the SW150P? @ F5 It would have much better light grasp and @ 750mm isn't too bad for DSOs. If you are using both as a guided set up, they a much too heavy for the EQ3-2. The slightest wind or vibration will wreak any long exposures The refractor + DSLR will give what seems to be a very small image of the galaxy, but if you where using a 1/2" ccd the image would look like this; Although your DSLR ccd is much larger, it's pixel size 5.5 is not that much different to the 1/2" sensor. The orient is 8.3 but the image with a QHY5 (5.6) is very similar. As you can see the pinwheel fills the 1/2" ccd quite well, so if you cropped the DSLR image, it would be of a similar quality to the 1/2" sensor. Before you spend lots of money on a Teleview, try the refractor on it's own, but with an Eq3-2 you're definitely over the edge! Buying a much sturdier tripod/mount would be a better Investment. If you really want to keep the EQ3-2, try a 500mm camera lens (you might get away with less e.g. 250mm) as the quide scope. They aren't as easy to focus and you'll need an adaptor to fit the camera but they are much lighter. I used a 500mm lens until I bought an HEQ6.
  4. datman

    PWStellarium

    Pinwheel in Stellariem using 500mm refractor and 1/2" ccd
  5. The chip on the Meade camera is tiny compared to your DSLR chip, about 6.3mm vs 43mm across the diagonal. This will make it much harder to frame objects, just making things harder IMO. It's also from the days of Win98 so pretty ancient.
  6. datman

    M13 -- Without guide stars?

    Not sure how different the stars look from India compared to the UK, but with a straight line between Arcturus and Vega, M13 is about halfway between them.
  7. I find Cartes du Ciel better for controlling the mount, easy menu access and especially the ability to "sync" to the desired object. Stellarium is very good for finding and looking at objects but I didn't find it's control system very intuitive. So I use both As already mentioned you'd need ASCOM,EQUMOD and Celestron mount driver.
  8. The ccd of the average video camera is only 1/4" compared to your current camera that is tiny. It will be much harder to get your object onto the chip. Pixel sizes are similar so the image would be the same size, you'd just have lots of background with the DSLR. I would suggest you stick with the DSLR until you are it's master, especially as it can do video. The DSLRs frame rate will be slower because of the image size. As I said earlier, you could use the diagonal with the camera to test that it works as expected. There would be some distortion and light loss but it will work. Once you have that sorted buy an extension tube.
  9. datman

    Something's going wrong...

    Well that's one thing off the list. I used to have my setup on wooden decking, and that's even worse than concrete. It's amazing how a small movement translates into a big wobble. As Louise says the best method by far is to use a computer to control the mount/camera. If you have the motor hand controller I think you have, it can be modified so it can be used with EQMOD. Not quite as good as a full blown GOTO but certainly better than what you have. You'd need an interface, RVO do one for about £45 but I'm not 100% sure if that's the right one. I'd have to check. I'm not sure if this is a possible self build. If you don't what to risk modifying your handset, I have a spare one. I also built an alternative version. I'd have to check it out but I'm pretty sure my version would give better speed control, it could also be made/programmed to have more choices. There is a story to this, but it's too long for here. Not particularly expensive to make, just takes time. It uses 2 x microcontrollers one for each motor, so can be programmed for different speeds. Have a think about what you want to, if you want to go down that route, let me know and I'll do a bit of research. I've just checked the interface at RVO, it would work. I live in Worksop so we are fairly close. David
  10. "I've got my 102mm refractor pointing at the planet, and have my Nikon D700 attached via T mount directly onto the eyepiece." Definitely out of focus! Hopefully you mean the camera is attached to the focuser tube via an eyepiece adaptor, or some sort of T mount to MCT adaptor. If not, you need a T mount with 1.25" EP adaptor, and an extension tube. You normally use a diagonal when viewing, so you need an extension tube of about the same light path as the diagonal. Measure to the angled part of the diagonal from where it comes out of the EP holder and from the angle to where the EP fits. Mine is about 75mm. You can test it by putting the EP adaptor of the camera into the diagonal,(assuming you have an EP adaptor on your T mount, you should then be able to focus. You could try this during the daytime on a suitably distant object. This is not the ideal way to image though, you need the extension tube. If you have any Barlows, you can turn them into extension tubes by removing the lenses. At f1300 you should see a small but very sharp Jupiter plus all of its moons. Once you've achieved this you can think about Barlows.
  11. datman

    Green moon

    You could try adjusting levels/colour balance using photo editor software, Gimp, Paint shop Pro, Photoshop etc. You could also try splitting the image back to RGB. Then reduce the green component. Recombine to see the result.
  12. datman

    Something's going wrong...

    I'd put my money on the stiff mount. Although you use both motors to align the object, once you stop doing that, only the RA motor moves. It's only when a PC/Guide camera are used that the Dec motor is also used to keep track. Don't forget the planets are following their own orbits too. The RA motor only tries to maintain tracking relative to the earth's rotation so planets will wander off. Depending on the Declination the speed of RA will also vary, the closer to Polaris the slower objects seem to go. This is all extra info though, it won't cause the faults you've shown us. Let's hope RVO fix the problem for you
  13. datman

    Planet photography

    Tend to agree, my attempts at afocal weren't very satisfactory. With 800mm you could try it on the moon to see how you get on before buying the Barlow. With a X3 barlow fl2400 Jupiter won't be very big, Mars and Saturn even smaller, but you'd certainly get something. Even X4 fl3200 won't be enormous. At these magnifications you could get Jupiter and some or all of its moons. Try Stellarium, you can set up your telescope, camera and Barlows, then it can show you how the target fits onto your ccd.
  14. datman

    Something's going wrong...

    Focus isn't brilliant, but that wouldn't cause the wobbles. Without some sort of guiding software which you don't mention, only the RA motor will be turning. Looks more like a wobble to me, you can see a number of the same star in different places. What do you mean by stiff? With the clutches released the telescope should turn easily. If it really is stiff, this would cause judder as the motor tries to overcome the resistance, then a sudden stop as the resistance bites in again, but that should be in the direction of RA Balance is relative, it's not like a knife edge balance. You may need to apply some motion, like a little tap/push, then see if it favours the weights or the scope Same for balancing the scope up or down it's length with all accessories (e.g. camera) fitted. Do this with the weights/telescope at about 90 degrees from parked so the telescope is horizontal. If you've not done it already mark the balance point with a bit of electrical tape. Providing you are standing very still, 5 metres away, and assuming nobodies doing Double Dutch with your cable it doesn't seem likely to be the cause.
  15. datman

    Bodes Galaxy

    Hi Just checked your equipment, 60s is about the most you can do without guiding equipment, which you don't seem to have. Sorry about that oversight
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