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Everything posted by Whippy

  1. That was on the Friday in my wok mate (the meatballs, not the dog wee!) . I think there was a bog and something on the menu that day... Tony..
  2. These have been around for a little while now and they do seem quite expensive considering you can get an Intes Micro for about the same cash. What appeals to me is the slightly larger secondary, if you can get a camera to focus on it, I think it'd make an excellent imaging platform as other MN's do. Tony..
  3. Welcome back Amanda, still got dodgy taste in scarves I see ... Tony..
  4. Becasue it's a standard focuser that Skywatcher use on all their newtonians. A dob is just a newtonian on a rocker box instead of an EQ or alt-az mount. You could easily take your OTA off your dob mount, add some tube rings and dovetail and stick it on an EQ mount to use it for imaging. Tony..
  5. TBH, for planets it's hard to see past a Mak-Cass or SCT due to their long focal length relative to their aperture. For example a 5" mak-casses made by Intes Micro and Skywatcher both have a focal legnth of about 1.5 metres which is a third longer than the TAL100. BTW, central obstructions cover a small amount as a percentage, nothing to worry about. Tony..
  6. Whippy

    IMG 20120618 193624

    From the album: Various

  7. Whippy

    IMG 20120618 193732

    From the album: Various

  8. There are two main types of Mak-Cass, the gregorian version with the mirrors silvered directly onto the meniscus while the Rumak version has a seperate secondary like an SCT. IIRC, the rumak has the advantages of the being easier to collimate due to the seperate seconday and a flat field. In terms of any advantages between a Mak-Cass and SCT, there's probably not a great deal in it. tony..
  9. With a DSLR you're going to need a flattener with either of those scopes, but either of those options would be a great first imaging scope. FWIW, the vast majority of galaxies are pretty small, with a DSLR and a small, short scope like these only M31 is going to fill your field of view. M33 and smaller are going to look pretty small, doesn't mean you can't image them though . BTW, tell your dad to spend the extra and get a HEQ5, it's a much better mount than the CG5. Tony..
  10. Virtually any camera can be used to take images of the moon, connecting the camera to an eyepiece (the 'afocal' method) using a bracket will allow you to do this. If the camera is able to expose for several seconds then some bright deep sky objects can be imaged too (M42 for example). I first started imaging using an old Canon Powershot, it's maximum exposure setting was 15 seconds but using several shots and stacking them, I was able to get a few images that way. HTH Tony..
  11. By your definition then, we're all using refractors as eyepieces, barlows flatteners/reducers all contain glass.... Have a look at this: http://telescope-optics.net/SCT.htm , no mention of CA... Tony..
  12. No. It's called a corrector plate because it corrects spherical abberations, not anything colour related. The Meniscus on Mak-Casses/Newts does something similar. I've read that corrector plates do bring CA into the optical train but it's so slight that it's barely measurable, let alone visual. Tony..
  13. *cough* SCT's don't refract... Personally, I always used refractors mainly because they're easier to use and I want an easy life . On your CPC, I'd get a 6.3 reducer/flattener as it'll make your imaging easier by shortening the focal length and speeding up the scope. BTW, have you got a wedge for the CPC? You won't get very far without one... Tony..
  14. In fairness (and something I should have stated in my original post), the 190 is a fantastic imaging tool as that is what it was originally designed for with it's larger secondary mirror (as was the RC) but it needs an EQ6, no doubt about it. You can put lenses onto CCD cameras as most of them have a T-mount on the body. IIRC, what some people do for filters is use a Gerd Neumann filter draw in the optical train. Tony..
  15. It really isn't. It's debatable even for visual, as mentioned in the previous post the MN190 has a corrector plate at the front and the tube has thicker walls so it's considerably heavier. IMO, the only scope that you could use without going into reducers/flatteners would be your APM 'frac. It's small and light enough to go on the HEQ5 with a camera and guiding kit. The RC is too slow at f9, you'd need a reducer. The 190 is too heavy as I've already mentioned, same as the LX200. Camera? I'd say use one of your Canons to get used to the idea of imaging and then take it from there. Spending £2k on a camera only realising that it's not for you is an expensive mistake. Tony..
  16. Whippy


    From the album: Various

  17. Whippy


    From the album: Various

  18. Whippy

    PLA MX

    From the album: Various

  19. The William Optics Field Flattener II (FFII) was designed for the Zenithstar 66's but they've been discontinued for quite some time but they do pop up from time to time secondhand. FWIW, the Petzval should have a flat field already. They have an extra element (or 2) inside the tube for that reason. The downside to your particular version of the 66 is that it doesn't have same level of colour correction as the 66SD so you may find that stars have fringes of colour to them. Tony..
  20. Just buy a standard SCT to 2" adapter? It's a standard SCT fitting on the back of the 66. Sounds to me as the Baader adapter is the wrong one. Tony..
  21. What they're probably referring to is the lack of 'astronomical' darkness. The Sun has to be more than 18 degrees below the horizon for it to have no effect on darkness. As we're coming round to the summer solstice, the sun no longer gets that far under the horizon so it doesn't get truly dark. The further north you are, the more pronounced the effect is. I've been on holiday in the highlands of Scotland during the summer and for all intents and purposes it doesn't really get dark at all. Tony..
  22. That's what I was getting at in your poll thread, unless you want to look for one of the LOMO 80mm APO's or something like a FLT98 secondhand then I don't think you're going to see a huge amount of improvement. I tried to be different a couple of years ago, spent a fair bit of money but I ended up with an original Blue Tube-d ED80 which actually had a rock solid focuser on it, there's just no getting away from them unfortunately! As you go up in aperture and focal length, there's a whole plethora of options not just refractors either(although the ED120 is hard to beat too) but for a budget, small APO it's still the ED80 IMO. Tony..
  23. Thing is, at a f/l of 600mm, why not just go for an ED80 and a reducer? Just as quick, colour correction will probably be just as good and half the price. In terms of small APO's for imaging, I haven't seen anything in the last couple of years at the budget end of the market that's going to be much better than the ED80. Tony.. Tony..
  24. AFAIK, the 80mm 'super' APO's using LOMO objectives were discontinued a fair old while back. These are the ones which are commonly referred to as the 'best 80mm scope'. They do popup from time to time secondhand in various tubes. APM, TMB, even William Optics did them for while using the Megrez 80 tube. These Chinese made designs may come close but I'd put money on the LOMO objectives being better consistantly. Tony..
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