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  2. Hi, There was a very recent thread on SGL only a few weeks ago about the exact same. william-optics-zs-66-sd-flattenerreducer Upshot of it was (I think) that the flatteners are now discontinued but the OP was looking for a substitute. I would look at this thread and maybe message the OP to see if they managed to get a substitute and where from. Steve
  3. I have a new (to me) SW EQ6-GT mount. On it I have mounted a SW 80ED with a standard SW 9 x 50 finder converted into a guide scope using the SW finder to C-mount adaptor. I use a SX Lodestar 2x guide camera screwed directly on the C-mount adaptor. I've always found that my mount calibration seems to take ages when using a finder/guider (up to 10 minutes). However, with the new mount it takes so many steps to calibrate that PHD2 runs out of time and calibration fails. If I try it using PHD version 1, calibration is successful, but still takes ages to complete. I am using 3 second exposures and the calibration step size set to the maximum value that the software will allow. I have checked and PHD2 is definitely moving the mount on each step, just not enough. What am I doing wrong?
  4. Thanks for the further replies, sorry I hadn't picked these up. More great reading and more things for my checklist. I see some folks responded to my most recent image so can see the focus issue seems to have gone - however I am now better prepared if it shows up again. Cheers!
  5. Thanks for your swift reply. Do you think both of them will be okay on a simple AZ-3? I will most likely use a simple red dot and 1,25'' diagonal and eypieces, and not of the heavy premium kind.
  6. While we are on this topic, hope no one minds me asking another question related to spectrum calibration. How do I do flat calibration? Same as with any imaging - just place flat panel on scope with the same gear arrangement (focus included) and I take subs? I divide spectrum image after dark calibration as normal? I'm asking because there is issue of vignetting - spectrum can "overlap" parts of "zero order" of vignetting and flats in this case will maybe produce wrong results? Or maybe it does not matter at all, and we flat calibrate to eliminate pixel to pixel QE variations and dust on sensor / any filters after SA? I assume that it might not matter because any vignetting will be incorporated in system response, but that means that recording needs to be done with zero order image at exact same spot each time (for both reference star and one that we are measuring)? It also means that spectrum orientation should remain the same with regards to sensor (but not necessarily to star field - as we can rotate whole assembly to get spectrum clear of background artifacts) - that is probably better as we want spectrum to be horizontal anyway, I guess. Anyone tried background removal procedure with "clear exposure"? I understand that it can be tricky as SA needs to be removed from optical train which can lead to slight focus change, and one needs to do linear fit on zero order stars to match intensity. I guess one can monitor FWHM / HFR to get roughly the same defocus of zero order image.
  7. Think you've answered it for yourself then, the ASI294MC Pro with say, the STC Duo Narrowband filter looks like a great combination. I think I'm going to upgrade to this as it will be a nice introduction to dedicated cameras from a DSLR and I could then upgrade to Mono perhaps when I've mastered cooling, gain, darks etc. all of that stuff. Since August I have had 4 clear nights, two with great transparency and seeing but two not quite so much. And that's every single night since then. If it's clear and moonless that's all we have had. I think if you live where clear skies are the norm (South of France for instance) then I'd definitely invest in Mono as you'd just have so much more time to invest in a Mono system, no rushing, no frustration in that you haven't completed a sequence of imaging or collected all of the data from each filter etc. As OSC Cameras improve as well I just think they're going to get better and better, and these narrowband filters are improving all the time as well. The QHY268C looks terrific, is in development, and will be around £1,900.
  8. Dang, so could well be soggy optics. I think most of my recent sessions have been after rain - its autumn. I was just hoping there was an upside to Newts. I don't think I could possibly ask my overloaded HEQ5Pro to cope with any more load, fans, dew heaters etc. I say thank you when she is tracking well - thankfully at home I can put the rig in a sheltered spot however the 2 weights are already sitting on the stop on the bar to achieve balance, and although I have two more weights it just isn't designed to take the load so I am reluctant to add more. Hairdryer or bust! Thus I was thinking get a decent 80/90 refractor, then later upgrade to an EQ6 (if I don't get sucked into a dedicated cooled camera). Trouble is I really like imaging galaxies so I like the power of the 200PDS (and I couldn't swallow the cost of comparable refractor....yet).
  9. If the objectives are figured to a similar quality (which is likely) then there won't be a lot of difference, just a touch more false colour around bright objects and possibly the F/9 might be able to handle higher powers wiht a touch more aplomb. I have a 102mm ED doublet that works at F/6.5 which I think uses an FPL-51 element but the false colour is not intrusive at all. A well figured F/7 ED doublet is a very versatile scope being able to handle both high powers and deliver wide fields of view at low powers
  10. Hello all. Time to move this on so it can have some use. Skywatcher AZ4 mount in very good used condition. Got this as part of a package I bought in the summer when I purchased a Stellarvue 102 frac from a fellow SGLer. I believe this mount has been owned by a couple of site members before me. Looking for 50 GBP including delivery. Payment by Bank Transfer or Paypal. ( buyer pays all fees ). Sorry - no overseas buyers. Will not be responsible for any issues arising from delivery / courier incident. Thanks for looking. John
  11. That's much better than the original, which was still really good.
  12. the scope room could do with being 500mm bigger, but I couldn't do it and maintain the angle to Polaris which lies directly over the warm room.
  13. Thanks for your replies; it is indeed the FPL-51 variant I'm talking about here. And I'm only interested in visual btw, not AP. I'm not really sure yet if I prioritize easy access to higher magnification or wider field of view. Until I have decieded I am trying to grasp the abberation aspect of f7(FPL-51) vs f9(FPL-53), and also how the weight/lenght difference will affect the use of the AZ-3 mount.
  14. thanks Rusty, no you can keep it we have enough here theres no room for anymore. charl.
  15. Thanks, Wim. I've downloaded it and I'll have a play tonight.
  16. https://www.cloudynights.com/topic/661652-new-ts-102-f7-apo-refractor/ No false color at 178x, recent optical formulas perform better.
  17. thanks Peter, agreed, but this prom is very bright the brightest ive seen for a long time which helps when shooting through the evil stuff . charl.
  18. thanks Dave, thay said it was going to be clear here mate, do thay ever look outside ? goodluck mate there other proms to if your luck holds. charl.
  19. I believe the TS 102mm ED (non-Photoline) uses an Ohara FPL-51 glass ED element. What type of glass the mating element uses is not defined. The F/9 100 ED uses an Ohara FPL-53 element mated with a Schott glass element. The levels of false colour visible in the F/9 are very low indeed from what I recall when I used to own one. The TS 102 that uses FPL-51 will be a lot better in terms of colour correction than an achromat of that aperture and focal ratio but is likely to show a little more false colour than the F/9 Skywatcher. As Stu says, the F/7 will enable a wider field of view to be delivered and the focuser is likely to be better than the Skywatcher. Depends on your priorities I suppose ?
  20. Which of the two TS f/7 apos are you talking about? They have a 599€ FPL-51 doublet and a 999€ FPL-53 doublet. https://www.teleskop-express.de/shop/product_info.php/language/en/info/p4964_TS-Optics-ED-APO-102-mm-f-7-Refraktor-mit-2-5--R-P-Okularauszug.html https://www.teleskop-express.de/shop/product_info.php/language/en/info/p9868_TS-Optics-PhotoLine-102mm-f-7-FPL53---Lanthan-Apo-mit-2-5--Auszug.html
  21. How true. Absolutely no skill required. Well done Charl! BTW: Do you want your cloud back gain now I've finished with it?
  22. The most obvious difference will be field of view, with the f7 giving you options with a long focal length eyepiece up to say 3.6 degrees or a little more. The f9 will be limited to around 2.8 degrees. There aren't many objects that big, but it is nice for the Veil and North America Nebula for example. There may be a slight advantage to the f9 for planetary and lunar observing and it will be a little gentler on edge correction for widefield eyepieces but f7 is still not exactly fast so the differences will be slight. It will also depend on glass type of the ED element and also of the second element which is as important, plus the quality of the figure and polish. The SW100 ED does have an excellent reputation I must say, and if widefield is not an issue for you then it may well be a good option.
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