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Everything posted by Merlin66

  1. Looks like you focused on the zero order star image....not the spectrum. http://www.astronomicalspectroscopy.com/gratings.html
  2. Yes, That's one of my books. I designed and constructed the Spectra-L200 Littrow spectrograph. This used a custom designed multi gap reflective slit plate from OVIO, very convenient. The latest generation of the 3D spectrographs are being constructed by guys like Paul Gerlach, John Paraskeva (BASS Project) and Tony Rodda among others. Some details on the astronomical spectroscopy group and webpage. http://www.astronomicalspectroscopy.com/instrument.html
  3. Vlaid, Check out the TransSpec spreadsheet - I think you have a copy. It shows the effect of focus and chromatic aberrations.
  4. RonL, Not sure where the "" However all barlows reduce light by 75% "" comes from. I could measure the actual transmission with the spectrograph, but I'm sure with today's coatings it's much better than 75%
  5. I've been using BASS project since its conception, and it continues to grow and is well supported. All my ProAm submissions have been with BASS Project processing. ISIS is great but is definitely focused on support for the Shelyak product range.....
  6. As Andrew has pointed out the cal 2 line should be H beta... A tip: Look at your earlier spectrum (copy attached) - look for the overall shape (caused by your camera QE curve) and note any similarities - bumps and hollows compare to the current spectrum. If you are using the same set up night after night, then the dispersion will remain unchanged, it looks like you have 8.65 A/pixel from your previous spectrum. This provides a sanity check with other spectra - in fact can be used to assist in calibration - one point with dispersion - Once you've done a few spectra successfully all this will become second nature.....
  7. I understand your decision based on $$$$$, but the Geoptic and ADM dual saddles are much better designed than the cheap and nasty SW solution. Your $$$$, your call. Ken
  8. I replaced the puck on my NEQ6PRO with the Geoptic dual version. works well for me. Ken
  9. Chris, At the moment BASS Project can stack images....but not directly from AVI files. You can use AS3! to stack your AVI files to a format usable by BASS Project.
  10. John, Adding a reducer gives smaller star images, but doesn’t always give a increase in resolution. Keep it simple for starters....... Get some data, analyse it then decide......
  11. I successfully use the Borg Helical focusers on all the Spectra-L200 spectrographs as well as the Spectroheliograph and PST Mods.
  12. Gav, Our webpage ( see signature) has many good links for both techniques and info which gives good info for all amateurs. Check it out.
  13. Steve, Well done - a great result!! Newton Rings are always more obvious when imaging the solar surface......
  14. My rule of thumb, when imaging in average conditions..... The acquisition focal ratio should be around x5 the pixel size in micron... This would mean 5 x 5.86 = f29 for the ASI 174, and f20 for the ASI 1600. I use an ED80 (fr=7.5) so a x3 Barlow would be good. Hence my x2.5 PM with the ASI 1600. I've only recently acquired a x3 Meade (and ES) tele-extender. I'll be trialling them when the weather improves.
  15. Not the same set-up, but I regularly use the x2.5 Powermate with T thread adaptor (or the Baader Hyperion x2.25 Barlow) in my SM60 DS/ ED80 with a ASI 174 or ASI 1600 camera. I do find that a T2 tilter is almost mandatory to suppress Newton Rings.
  16. Gav, You can certainly use the gratings either the SA100 or SA200 on the 10" - it depends on the available spacing between the grating and the camera chip. Keep things simple to start with....get the practise in acquiring the spectral image and the gain experience in the spectra processing. "Spectroscopy 101" I must say that mono cameras give better results than OSC cameras..... Richard Walker's "Spectral Atlas" https://www.cambridge.org/core/books/spectral-atlas-for-amateur-astronomers/32126CD730EBA49238F9318C16B90523# Is highly recommended, is gives fully annotated spectra of all the star classifications, as well as other very useful information and data. François Teyssier 's "Low resolution Spectroscopy" is also well worth studying. http://www.astronomicalspectroscopy.com/files/SpectroscopieBasseResolution_En.pdf
  17. John, Your ASI 174mm with a 11.3 mm wide chip would be a good starting point. I'd suggest starting without using flats and darks. The ASI 174 is a pretty "quiet" IMX 174 LLJ chip and spectral flats with a grating are problematic. I call using the gratings "Spectroscopy 101" - it gives you the opportunity to gain practise in acquiring spectral data and experience in processing the data. I use and recommend John's BASS Project for spectral processing. https://uk.groups.yahoo.com/neo/groups/astrobodger/info
  18. Martin, Yes, been through all the guides, and some other pages... The issue was to end up with a WCS indexed image - I can then open this under CdC and check not only the plate solving but look for other interesting objects in the FOV. I seem to have found the solution! You need to add a "Work_directory = C:\temp" (or similar) to the config file. After solving the image, AT produces a series of files (in the nominated "temp" directory...) None of these are fits files - like the WCS calibrated image obtained from Astrometry.net. The answer is to use the "finder".new file and rename it to a .fits. This is then recognised by CdC and can be displayed......
  19. I'm pretty sure all the Baader filters have a notched edge which helps.
  20. I've installed the latest version... What I'm trying to achieve is to solve an image from my hard drive (previously captured from my eFinder) The Configuration site states: If you want to solve images on disk and store the annotated images from astrometry.net solver, remove the --no-plots -N none options and set the work_directory in the configuration file to a temporary directory. Using the FileOpenCamera module you can annotate existing stacked images and the results are stored in solving order under the work directory. I can't seem to find the work_directory in the astrotorilla.cfg?????? Also, where is the FileOpenCamera module????? So far, it seems to find the selected GOTO image from the computer, and indicates that it has solved the image....BUT no CWS image found???? Any Astrotorilla users out there who can help. Thanks, Ken
  21. Louise, Looks better! Why not try your data in BASS Project? You may find it easier....
  22. As I’ve recommended in the past, before using spacers etc give the threads a smear of boot polish, this will significantly reduce the chances of seizures. To separate them another trick is to use the anti slip map you can buy for kitchen drawers, or a rubber flip flop and press the spacers into the material and twist.... Rubber gloves have also had success.
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