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Merlin66

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Everything posted by Merlin66

  1. 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)
  2. Well done, Nigella - good to get some recognition!
  3. Kev, Sounds like the grub screws which hold the gears to the shaft may have come loose????? I'd double check that before panic sets in..............
  4. 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
  5. 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
  6. 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.
  7. Whooooo!!! That's scary!! I use a very similar power set-up with AstroZap dew heaters and controller (#AZ-720). Never experienced anything like that.
  8. The ZWO website shows 6.5mm camera back focus....this means that the front of the camera should be that distance in front of the prime focus. https://astronomy-imaging-camera.com/product/asi183mc-pro-color An image of your set-up would help.....
  9. Can't solve your SharpCap issue.... Have you tried the camera in FireCapture - just to verify and check the drivers? (I use my ASI 1600 under Firecapture)
  10. I use the ASI 1600 for solar imaging..... I just stick with the Unity gain (139) (In FireCapture) and gamma 50. The exposure set to give a good histogram +/- 80 % Seems to work for me. Ken
  11. 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.
  12. Well done! Just shows what a good LS50 mod can achieve on a 160mm aperture system. Excellent result.
  13. Fabio has just released his latest update to AstroArt V7. It just gets better and better. You can download a trial version.... http://www.msb-astroart.com/default.htm
  14. 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)
  15. 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
  16. 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.
  17. 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.....
  18. 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
  19. Still clouded in..... Nothing showing in GONG today.... http://halpha.nso.edu/
  20. That's for Daystar "solid" etalons..... not for the air spaced etalons used in the Coronado and Lunt instruments. A claim was made that extreme low temperatures could affect the central wavelength of the blocking filter and cause to go "off band" reducing the transmission and performance of the instrument. Lunt now supply a heated rear plate which can be fitted to the BF diagonal to alleviate the problem. Here in Australia I'm more concerned about the effects of elevated temperatures. I looked at getting a Quark, but Daystar said I'd have to order a "special" which could come on-band at ambient temperatures above 40 deg C (The quark has no cooling capabilities and relies on heating only to come on-band). I declined the offer.
  21. The Synscan manual for V5 states the added hand controller USB port is to allow direct connection to the PC USB port. Sounds like a reasonable update from the ol' serial connection. (Page 20) https://www.telescope.com/assets/product_files/instructions/IN_620_Rev_C_SynScan_Hand_Controller.pdf (The special EQ DIr cable used by the direct mount connected EQMod gives the correct signal to the mount and won't fry the mother board)
  22. Yeah, some interesting proms.... Pity we have heavy cloud down here in Victoria, Australia, tried to image them earlier this morning but beaten by cloud.
  23. John, Welcome on board! Congratulations on your purchase..... I have and use an HEQ5 and a NEQ6 mount. Both these mounts are controlled from a local laptop. Not 100% sure about the differences with the EQ6-R Pro and Synscan V5 (I'm still using V3) If you are already comfortable using a PC and planetarium program then you could go for either ASCOM control or EQmod to control your mount. You can connect the Synscan controller to the PC and set the mount type to Skywatcher EQ, this will give you PC control. You still need ASCOM installed and a planetarium program. EQmod is an interface software, between a planetarium program and the mount. It needs the latest ASCOM drivers/ interface. EQmod also prefers to "talk" direct to the mount, bypassing the Synscan hand controller. To do this you need a special cable between your PC and the mount - an EQDir cable. I use Cartes du Ciel with my EQmod set-up. Works 100% for me. Read up on the EQmod capabilities and satisfy yourself that it's what you want..... http://eq-mod.sourceforge.net/introindex.html https://ascom-standards.org/ https://sourceforge.net/projects/skychart/
  24. Glad you got things sorted out.... Time to talk serious..... The instrument you're building is very sophisticated, containing many optical surfaces and requires some dedication and rigour to complete, test and eventually use. The object of the build is to end up with a capable, usable spectrograph. To achieve success all the optics must be clean, positioned and aligned correctly. Re slit focus - The slit gap, a few microns when viewed through the system should be measured. The FWHM of the slit gap will confirm the focus. If you use the collimating lens plus a long focus lens/ scope to view the slit gap then you also need a camera. The ratio of the focal lengths of the viewing lens and collimating lens can give some magnification factor, where the slit gap appears greater/ less than it really is. The slit gap, say 20 micron when used with this system - assume the collimating and viewing lens are the same focal length with a camera which has 4 micron pixels, will appear as a 5 pixel wide image. I use AstroArt to do all my imaging, and it has (like many other programs) a "profile" option. You can use this to analyse your image of the slit - to measure the FWHM. The collimating lens should be adjusted to give the minimum FWHM slit image. In the LowSpec design the imaging/ collimator lens have the ratio of 80/ 125, this gives a ratio of x 0.64 - this means the slit gap will appear smaller than actual (say 20 x 0.64 = 12.8 micron, or less than three pixel in the above example!) If the collimator is not correctly positioned, then the exit beam to the grating will not be fully collimated and parallel which can compromise the performance of the grating, and the instrument.
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