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Everything posted by prbirdo

  1. Hers to answering my own questons http://www.celestronimages.com/details.php?image_id=9484 However How do I connect up my CG5 mount to PHD software? That is my big question.
  2. I am trying to piece my cheap as chips rig together to get some decent images. Ive aquired second hand over the past couple of years bit by bit. Celestron 8* SCT with bobs knobs (good old bob)100 quid (Had to clean it up alot but the Optics are good.) CG5 mount 200 quid of old scope. [Further reading has left me thinking this mount is quite limiting but I want to see what I can get out of it] Cannon 450D unmodified with 120 quid (auto focus does not work.. not a problem) + Astronomik filter + APT software its brill! Celetron Radial Guider 100 quid Polar alignment scope Bit of luck I have been aligning the scope up and correting the motors slight deviations using the radial guider. My eye hurts. Im planing to use a meade DSI 1 as an auto guide. But cannot find the best way to set this up. my initial plan is to attach the DSI to the Radial Guider inplace of the rectile eye peice. Will this work? . The mount does have an autoguide input. I want to use PHD software.
  3. Also is the on board cannon noise reducer and high iso reducer worthwhile?
  4. cheers, yeah i have a 6.3 reducer ( M31 tight squeeze) and astronomik filter, so more frames is more important than over all image time?
  5. Ok I am using a Manual Guided Celestron 8SCT on a CG5 mount. I am getting best results from around 10 min exposures. But it is easier for me (and reduce stacking problems and time) to jus do long exposures. What is the longest exposure I can get on a 450d on M31 before heating of the 450d's CCD will reduce the image quality by too much.????? Cheers
  6. can i ask how long as each exposure, fancy cracking m31 myself
  7. they are lead batteries you need to keep them topped up, charge at least 2 times a month otherwise the reaction inside srews up. on the plus if you charge when full it does not damage the battery. A deep charge may rescue you batt, do it as soon as you can, leave it on for 11hrs or so. (not in a fire catching area --just incase!)
  8. ive have a skywatcher 7ah rechargable batt, its done me proud so far. its a lead batt so as long as you keep it constantly topped up it lasts and 1 charge will give me around 2 5hr sessions (without hair dryer on) get them for about 30 quid) they use a cigarette lighter (batt) to ac adaptor (mount).
  9. cheers, hmm trying to find a similar adaptor from the uk or might get an Astronmik CLS-CCD clip in. ?????
  10. got a cg5 sc6 with a focl reducer. the radial guider plugs straight onto the reducer then my camera fits on to the end of the radial guider. im struggling to find an attatchment so i can put a light filter before the camera. and suggestions???
  11. you can pick one off ebay for around a tenner, simple but works fine.
  12. i have seen the 80ed used alot, makes good sense
  13. the little question! What would be the best scope for astrophotography? The SC6 is a little slow. Focal speed, value for money, results????
  14. i'll be back with more soon once i've read up on that processing. now question of the day... is it worthwhile to modify my camera, i know its good but is it really worth it?????
  15. as above! (can you guess which direction manchesters in???)
  16. cheers guys, been a bit ill with that vomiting thing, getting round to it! here's a raw of orions neb (1x1min iso 800)-- still working with them. also me taking some pic's i took tonight. (11x15s iso 1600) both on canon 450d unmodded, and the sc6cg5. first atempts at photographing anyhow.
  17. Guys your heros, managed to stack some images of M31. now Im still suck. whats the best way to alter the histogram to release the detail? did ok with the great orion neb but M31 seems tricky. know this is a whole subject in its self. Played around with the levels on DSS, what is the best approach? For orions neb I reduced the red until it made a 'diffraction pattern' on the histogram this seemed to bring out the h-alpha and most detail ( a bit red!) (also have corel paint, photo and draw i know will do it better once i know)
  18. I have not tried turning off drizzle, will gove that ago. star amoount wise i've used 10% all the way to 90%. i'll try turning off drizzle and get back. cheers
  19. got a c6sgt advanced goto. 6.3 reducer and a d450 (or will have soon d300 upgrade) (prime focus) its seems no matter how many exposures i take and load into DSS i can not get them to stack -- or actually it only uses one image from the load i put in. i've tried it on M31, the orion neb, pledies, ring neb. -- got some great amazing single shots. But ive never done one successful stack. (managed to put darks and flats in!. kicking myself and i must be doing something wrong. Think i struggle when selecing how many stara it should see in the registering part. exposures loads of them vary from 30s, 1min's, 2mins. 4mins. anyone got any RAWs i could practice with????? [sick of being a dss retard]
  20. and to aswer my own question...... Adding a star diagonal to a Cassegrain type telescope with moving primary or moving secondary focusser, can indeed effectively increase the focal length of the telescope. Any increase in distance between the eyepiece and a secondary which has power, changes F. The principle is the same as moving an eyepiece towards or away from a Barlow lens, the effective F of the telescope changes, hence magnification changes. The word 'effective' I use in these cases, symbolising a change in F without the corresponding change in the linear length of the converging beam. In real terms the change in F is true. Types of telescopes where this is true - All SCTs (with moving primary focussing) e.g. Celestrons and Meades. All Maksutov Cassegrains (with moving primary focussing) e.g. Synta Maks (Skywatcher, Orion). Intes-Micro Mak Cass, Mirage Mak Cass, Meade ETX's and LX 7" Mak. Celestron 4" Mak. Questars (I think, although not sure about the precise focussing method, it is many years since I took one apart). Cassegrains with moving primary or secondary focussing e.g. Tak Mewlons. Of course this means that all of you out there with SCTs have telescopes with no one focal length. The possibilities are endless. This discussion was brought up briefly on another thread 'Mak replacement for Newt' in this Equipment Discussions category. Some numbers are mentioned in this discussion. Every Cassegrain type telescope with movng primary or secondary, has a premium position behind the primary where an eyepiece should be placed. This position roughly corresponds to the correct position for an eyepiece, focussed at infinity, where Lower order Spherical Aberration is at its least. This is also what some manufacturers of these type of instruments regard as the 'back focus position'. E.g. With Celestron, the C8, 9.25 and 11 (not sure about the 5 or 14), have the correct eyepiece position some 90mm to 100mm behind the rear cell. At this position an eyepiece focussed at infinity is working (roughly) at f/10. An eyepiece placed directly into the visual back means the f/ is less than f/10, F is reduced and magnification is reduced. The opposite is true if the eyepiece is pulled further away from the rear cell. I have worked out (by simple true field measurements within the apparent field of an eyepiece) that placing an eyepiece 120mm further back from the normal back focus position, on a 5" and 8" mass-produced SCT, decreases the true field by about 20%. This means that F has increased by 1/0.8, which is 25%. So, e.g. in the case of a C8, a 2" screw-fit to push-fit adaptor, attached to the visual back. then a 2" push-fit Star Diagonal added, then the 1.25" adaptor in the diagonal pulled out by about 1", and a 1.25" eyepiece inserted and focussed at infinity, F is no longer 2032mm but has increased to approx. 2540mm. f/10 becomes f/12.5. A 10mm eyepiece changes from giving 203X to 254X. You can take it too far and introduce mechanical vignetting, by pulling the eyepiece too far back, so using the system as a weak Barlow has its limits. However, you can genuinely claim that your telescope has no focal length, or that it has many focal lengths. So, the diagonal itself does not have a focal length, as it does not have power, it is plano. But, it does contribute to a change in F and f/ in mirror focussing Cats or Cassegrains. Best regards Chris whoever chis is
  21. i used the sky watcher on on my old 130p. did the job perfectly. you just have to make sure its in tight. also if you use it you can then use a star to get it completly spot om. I would only get one if you have a newtonian scope as its pointless for sct's. (using a stars quicker)
  22. I hace a SC6agt scope with celestrons reducer (6.3). I have a T mount and a eye piece projector. I am using a cannon 450d (unmodified). Mainly I have been using the T mount focusing the telescope as a lens for planets and deepsky. By using the T mount and star diagonal I can change to a larger field of view which is nice for deep sky. compared without the star diagonal. How will this effect the focal length and ultimatly the exposure time? would i be better using evepiece projection? (how does this effect the exposure time?) Thanks Paul
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