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Merlin66

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Posts posted by Merlin66

  1. Very nice result!

    Re AS3! (I use AS3! ) I've done some comparisons on my solar images using 10/50/75 % "best frames" and to be honest the 50% result was probably better than the top ten 10%.

    Worth trying yourself to see if it works for you.

    Ken

     

    • Thanks 1
  2. Re. Microlens artifacts with the ASI 1600, other than the example on CN I haven’t seen any issue with the multitude of images from this camera.....

    Maybe I’m missing something???

    I use the ASI 1600 ( a replacement for the rejected ASI 183 ) for solar imaging, with no issues.

     

  3. Back in the 60's I started out with Norton's Star Atlas.....helped me come to terms with astronomical terminology and finding my way around the sky.

    Now in it's twentieth edition. it has enhanced charts, each chart with a list of "Double Stars", Variable stars", "Clusters nebulae and galaxies" to observe.

    Highly recommended.

    https://www.abebooks.com/servlet/SearchResults?isbn=9780131451643&n=100121503&cm_sp=mbc-_-ISBN-_-used

  4. Meade series 4000 "super plossls" - the early smooth sided, marked "Japan" on the black body were actually five element design "Masuyama clone?", the later versions marked "Japan" or "China" on the chrome barrel were four element similar? to the other Series 4000 eyepieces.

    Which one did you test?

     

  5. I've been using the Borg equivalent non rotating helical focuser on Spectra-L200 instrument for almost ten years.

    They work, and work very well.

    (when connecting to the external T thread, the eyepiece screws need to be removed - and replaced by dabs of BluTak to limit light intrusion)

     

     

  6. Being a manufacturing/ production engineer for fifty years, I appreciate your frustrations.....

    BUT you're currently playing with, I think we agree, a scope from the bottom end of the market.

    There are thousands of amateurs using refractors/ reflectors which although not perfect are capable of performing to their needs.

    I do have one serious area of "complaint" - the "safety recess" found on eyepieces/ accessories was invented by the Devil - and should be banned.

    Ken

     

  7. Onwards and upwards!

    A centre spotted paper target over the front of the objective - the laser spot should hit centre......

    I also use a Cheshire collimating tool - illuminate the side and look at the reflection doughnuts at the objective. Ideally they should be uniform and concentric.

    That's as good as things need to be.

    Suiter's "Star testing Astronomical Telescopes", p122

     

  8. I used to work in Muskoka, Ontario where it got down to -20 deg c in winter!!!

    I still have a small scar on my eyelid where the skin froze to the eyepiece!!

    (The grease also froze in my tracking mount....)

    Things are a bit easier here in Oz, but observing at +30 deg c at night (!!!) has it's issues.

     

    • Like 2
  9. I have two set-ups....

    My HEQ5 for solar is located on the balcony and connected to the indoor laptop using 5 Mtr extensions - the power (at 15V), the Synscan controller, the focus motor, the tuning motor and the camera.

    Works well.

    I also have a NEQ6 pro in the observatory, connected back via a local laptop and Cat 6 cable (Teamviewer) to the office.

    I use EQmod / ASCOM/ CdC to control the NEQ6 - this arrangement may work for you using an extended cable and powered USB hub.

    Don't know anything about WiFi connections - sorry.

     

  10. 42 minutes ago, George Gearless said:

    'I-used-to-be-rich-before-I-bought-a-solar-telescope'

    I certainly fall into that category!!!!

    The Quark solar filters - the Chromosphere version has a slightly narrower bandwidth which allows better contrast and definition on surface features - sunspots, filaments, spiculae etc.

    The Prominence version has a much wider bandwidth which allows the Doppler shift in the proms to be included in the view, giving a more pleasing rendering of the various features - hedgerow, surges and sprays etc.

    Having said that many (I mean most) users go for the Chromosphere version to try to get the best of both worlds.

    An energy rejection filter (ERF) is an expensive filter which allows the Ha light to get through but basically blocks all the other light and heat energy. These can cost hundreds of dollars!

    https://www.baader-planetarium.com/en/baader-d-erf-energy-rejection-filter-(75---180mm).html

    Without an ERF on a scope like the Mak you run the risk of cooking it! Overheating the secondary etc etc etc. Don't do it!

    The Quark is basically designed to be used on a >f5 refractor. With smaller apertures <100mm you can get away with using a UV-IR filter close to the Quark as an ERF. Larger scopes need an up-front $$$$ ERF.

    For solar imaging a fast frame mono camera is the way to go. I use an ASI 174MM and an ASI 1600MM with FireCapture software for my imaging. ( I use a double stacked SM60 on my ED80 with a BF15 blocking filter)

     

     

    • Thanks 1
  11. Louise,

    The good news is light pollution doesn't existing in spectroscopy!!

    Valerie does her work from the centre of Paris (!!) Christian works from his balcony near Toulouse.....

    We can remove the unwanted sky glow signal - sodium, mercury lights etc. very easily during processing. LED lights.....well that is more difficult.

    Ken

     

  12. Louise,

    I should also have added that spectral exposures can be very long - to build up the signal and improve the SNR. I use 20 x 240s min subs (!) hence the benefit of a cooled mono camera.

    I don't know if SharpCap can handle cooled cameras and long exposures.

     

    etacar_20190315_394_KMHarrison.jpg

  13. Louise,

    Don't know how ShapCap handles darks, alignment and stacking. I use an ATik 314L with the Spectra-L200.

    Buil's ISIS, Valerie's VSpec and John's BASS Project are all suitable for the spectral processing - taking the raw spectral image to a 1D profile.

    Edit: Misread... you mention IRIS not ISIS. Yes, this can work, but it's now getting a bit dated.....

  14. Louise,

    Yes, you've got the main points.... the telescope focuses the star image onto the front of the slit plate (and seen by the guide camera), the light goes through the slit and is made parallel by the collimator... the beam hits the grating, the light is dispersed into a spectral image which is then focused by the imaging lens onto the CCD chip.

    At this stage bench testing is the way to go...a bright desk lamp (or fluoro) shining into a paper diffuser on the entrance should give enough light to work with at the slit.

    The "test" imaging system should be focused on infinity and not re-adjusted during the test. If the collimator is correctly positioned, the slit gap will be in focus.

    You may be able to use your dummy grating (mirror on 3D block) to align and focus the collimator and confirm the final imaging arrangement. 

    Which program will you use to obtain your spectral image? It should be able to analyse the image (using the measurement/ profile tools) and give you a FWHM result - mine (AstroArt) shows the result down to 0.01 pixel.

    Ken

     

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