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About Bukko

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    Star Forming

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    SW France
  1. I am successfully using 20cm bore heavy walled pipe for my piers and the only issue is welding top and bottom plates. My MIG welder is not quite enough for the task and I needed to pre-heat the steel before welding. I don't see a problem using a length of RSJ, the rolled type is very heavy in section so if you can weld it, it should be fine. Good luck, Gordon.
  2. Hi Vlav, A few years ago, my youngest son pointed our 12" f4 Newt at the hercules cluster and got about 25 hours of luminence under less than ideal conditions. From memory, the galaxies are in the region of 200 to 400Mly distant so hopefully the attached will help support your concept of looking back around 1Bly distant. A bigger (16"+?) in much better skies might manage it and in Luminence, I don't think the redshift is big enough to spoil the show... Hope this helps. Gordon.
  3. I agree with Dave, looks like coma. I also have the 50mm STM lens and have been very unhappy with it. I really miss the marked up manual focusing ring and have failed to get a reasonable focus from it. I am seriously thinking about ditching it for the f1.4 with the ultrasonic motors. But lots of credit to you for getting such a nice image from it. Gordon.
  4. Bukko

    Guide Cam... CCD vs CMOS

    So, to close out the topic, in the end, I went for the SX Superstar. I already use one as a guidescope on my NEQ6/OO VX12/ SBIG ST8300 rig and it works great. Vlaiv's comments about using CMOS were reassuring, but I am pushing my luck with the rest of the system and so I ran back to a safe bet for the guide cam. Anyway, I will start building the rig in October and hope to have first light by the end of the year. Many thanks to all who contributed. Gordon.
  5. Bukko

    Astrodon vs... The rest.

    So.. To close out the discussion, I thought long and hard about what to do and now, several months later, I am finally back in the UK (I have spent most of the last 4 years on assignments, firstly in Saudi, then in Singapore...) In the end, I went for the Chroma filters, NB at 3nm and then a matching set of LRGB's so I can load the SX Maxi wheel in one go and not have to mess around swapping carousels. The exception was the Ha, which was not readiy available in 3nm so I spent the extra on the Astrodon. I am now in the process or re-locating to the SW of France where I will build the systems up and hope for first light before Xmas. Thanks once again to all who contributed and wish me luck !! Gordon
  6. Bukko

    What's your dream telescope/equipment?

    Amazing coincidences for sure... I am sure we are not related, but my oldest sone is also called Andrew... Thanks for the good wishes on the move, I know we will get more access to the night sky than currently available here. Gordon.
  7. Bukko

    What's your dream telescope/equipment?

    I am now living my dream scope - having retired (for the second and final time) my dream scope is the same as Andrews - The ODK16 on an MEII.. Planning my move to the South of France in the next couple of months to try and maximise the system...
  8. I am using the same Rowe corrector on an f4 Newt and get pretty tight rounded stars over the whole CCD. The corrector back focus distance should be around 96mm as you say. This is from the last lens to the imaging chip surface so is plenty for my CCD, filter wheel and OAG, with enough to spare that I need an extension tube to make up the difference. From your description, I would look to collimation first or possibly there is some astigmatism present. I have never experienced it, but possibly pinched optics... Good luck. Gordon.
  9. Bukko

    Guide Cam... CCD vs CMOS

    Hi Kevin, That is a serious camera... Something like 37mm x 37mm sensor size will still take up a lot of the 2.7" available through the OAG. I sketched it out and you still only have a few mm's to spare without impinging on the light path to the main sensor... Having said that, your whole system looks pretty serious too !! Anyway, when you get the chance, it might be worth pulling the whole camera assembly and taking a look to make sure there is a bit of clearance. Not sure I can help with the reflections, it might be worth a dedicated posting to see what other members think.. Good luck. My system is a retirement present to myself. I am on a final project in Singapore and the agreement with Mrs Bukko is I get to keep every penny earned to treat myself. I already have an Ultrastar, purchased it for solar imaging on my 60mm Lunt. Being UK based and having to work for a living, I have had very little time to play with it. They are expensive for sure, more than the CMOS you got for guiding and even with a hefty budget, I am balking at getting another just for guiding... Gordon.
  10. Bukko

    Guide Cam... CCD vs CMOS

    Hi Kevin, I did a scale drawing of the 16200 CCD in a 2" system and there was only about two millimeters available clearence in the light path between the CCD and prism. Assuming this is how your system is, the prism needs to be pretty much tucked up as far as it can go so not to cast a shadow on the CCD. I am going to use the SX Maxi filter wheel that has a built in OAG. The throat is closer to 3" so there will be no issue. The prism will be out of the FOV of the 50mm filters. The prism is 10 by 8mm. Like most other things, I guess it is not a good idea to capture the whole surface area and the 174 series of CMOS sensors are bigger than that. On reflections, my new scope is a UK built 16" Orion Optics ODK - basically the equivalant of the Planewave CDK design. It now comes with a 3" Feathertouch so no problems expected from that. It is also a solid carbon tube, so no stray light from the truss. It will not see first light for a few months but I will look out for any reflections. I baulked at the cost of Astrodon filters, so went for the nearest equivalent set from Chroma. Could not get a 3nm Ha so had to pay the extra for the Astrodon. Looks like you also got an MEII? Mine arrives tomorrow... Gordon
  11. Bukko

    Guide Cam... CCD vs CMOS

    Thanks Kevin, Interesting choice... One thing with my original suggestions are they all cover a smaller area than the prism on the OAG, so having a larger working are would help with guide star. Similar to you, I will be working on around 2700mm fl so you raise a good point about making the most of the available FOV. For a whole lot of other reasons, I am comitted to the SX 16200 camera and the Maxi OAG. This has a 1" C type thread and I am struggling to find a 174 chip that has the same thread form or adapter available. I will keep looking for a while and if I can work it out, maybe this is the way forward, as you saay. Gordon.
  12. I have a SW Equinox 80. It was OK for weight and balance until I replaced the focuser with a Moonlite. Made the whole thing back heavy so consider the focuser will also add a lot of weight to it. My second Frac is a WO 110 f7 carbon triplet with a huge focuser and corrector. It is so much heavier, despite having a carbon tube.. Reasuringly heavy, I would say... Gordon
  13. Bukko

    Counterweight woes

    From what you say, you only want this for testing. So I am guessing this also means you really do not want to spend time and money in doing this? I would suggest borrownig some kitchen weights and taping them to the OTA. To avoid leaving marks, first wrap something around the OTA and then attach the weights to that, the weights from a kitchen balance should be enough. Failing that, a small(ish) hammer taped on should also be enough. Good luck Gordon
  14. Bukko

    Guide Cam... CCD vs CMOS

    Thanks Vlaiv, Apart from the Lodestar, the pixel sizes are pretty small, so it all boils down to trading off the download times vs the bit count and SNR. On balance I think the CCD still wins out and choosing the best CCD also gives good SNR and reasonable download times. My mistake on the OP, the CCD bit count was only 10 bit, not 12. So I think I will go for the CCD. Gordon.
  15. Bukko

    Guide Cam... CCD vs CMOS

    Thanks, Merlin, I understand it is not neccessary to run an OAG with high resolution, but my existing guide camera pretty much matches the pixel size of the main camera. It does work well hence the thought of doing the same; the Lodestar X2 CCD footprint matches the other cameras I am considering and does offer even higher QE, so I guess I should also consider this one too. If there are no supporters of the CMOS being a better option, then my choice changes to LodestarX2 or the Superstar... 4.65 micron at 50% vs 8.2 micron at up to 77%... My planned main camera is the SX Trius 46 - 16200 based CCD with 6 micron pixels... Choices, choices...

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