michael8554

If you guide with it expect to get Differential Flexture........... 😆 Michael

The maximum run for USB2 cables is 5 metres, so your unpowered 10 metre cable should be an Active cable, which reclocks the pulses - it probably is. A lot depends on the power demands of the cameras, try it and see.. I'd prefer a Powered Hub on the tripod, you could get a 5 volt Hub and run it off a battery pack: https://www.ebay.co.uk/itm/3800mAh-High-Capacity-Rechargeable-Battery-Pack-fits-for-Wii-Balance-Board/174571659262?hash=item28a5481ffe:g:j1MAAOSwfUxe~use. Low voltage so no safety concerns. Michael

Most telescopes require 12 volts, but the ETX90 only requires 9V. The plug should be centre positive. The correct plug size is 5.5mm with a 2.5mm centre pin, not 2.1mm Make sure the unit is a Regulated Power Supply. Cheaper Unregulated Power Supplies do not supply a steady 9 Volts under load. Michael

Moving the prism up and down adjusts how far into the main imaging light path the prism protrudes, it doesn't affect the guidecam focus.. You adjust that to just avoid a shadow on Flats. Once that is adjusted and locked-off, focus the guidecam by moving it's position up or down the periscope, after loosening the other screws. You can do this during the day on distant landmarks. Star shape may not be perfect, but PHD2 will handle misshapen stars. As newbie says, get the imaging focus correct before adjusting the guidecam focus. Then in future only adjust the imaging camera focus. Once that is correct, the guidecam will be in focus too. Michael

The Baader MPCC requires 55mm with the thin lock ring in place, or 57.5mm spacing without: The Canon sensor is 44mm inside the body, Nikons are 46.5mm. So with an Nikon 8.5mm T Ring the spacing is 55mm. So no need for any extra spacing. Michael

Lovely plumage, the lacewing......:-> Michael

Wired or Wireless/Buetooth mouse ? Try different USB ports. Michael

For future reference, the teardrop-shaped stars pointing towards the central focused part of the image are suffering from Coma. That's an effect often seen (to a much lesser extent !) on both Refractors and Reflectors, and is removed by a Coma Corrector, screwed between the camera and telescope at a specified spacing to the camera sensor. But remove the eyepiece in your case ! Michael

Hi Mark The Guidescope has a 120mm Focal Length, so measure 120mm from the front element, that's where the guidecam sensor has to be located. Roughly eyeball that with the rotary focuser about halfway if possible, then try during the day with SharpCap on Auto Exposure, pointing at a distant landscape. Fine tune at night on a star, if using PHD2 you can adjust for minimum HFD on the Star Profile window. Michael

According to the PDF, Meade has used a number of methods of attaching the Secondary. If yours is the 6-Screw version, seems like there should be springs. On 3-Screw versions there aren't any springs. Michael

I was assuming that even in Alt/Az mode, the 8SE needs an accurate "Home Position", probably level and pointing true north ? Michael

Then presumably you have plans to adapt the top plate to take the 8SE, and to provide Az adjustment ? Michael

I'd suggest tilt. More vignetting on the left side could suggest that the optical path is pointing slightly to the left. Meaning the left edge of frame is very slightly closer to the camera than the right side. Michael

The missing info - is the 8SE on a wedge, or in Alt/Az mode? Or maybe you've de-mounted and it's now on an EQ mount ? Michael

That looks good, Time Zone W06, and DST Off ? And the stuff you've probably already done: Initial setup position is vague. But the instructions say enter Azi = 000, and Alt = 00, So that suggests have the optical tube pointing true north, and the optical tube horizontal (with the tripod as level as possible). Then carry out the Star Alignment. Michael

The CC might fit inside the 2" focuser. So find out the thickness of the filter drawer. Move you existing kit that far out of the focuser. Can you still focus ? Michael

From the PHD2 Log: During Calibration PHD2 is moving the mount in RA. All the Calibrations were carried out a 1800mS Calibration Step Size, I can't see any at 3000mS ? On your only attempt at guiding, PHD2 calculated the Guide Rate was only1.7arcsecs/sec, you need at least 8arcsecs/sec. PHD2 calculated the PA error during that guide attempt as 23arcmins, you will need better than 5arcmins if you're not guiding in Dec. Guidecam focus was HFD =4.46, try getting that lower by watching the HFD reading in the Star Profile window as you adjust. Michael

Most likely you have an error in the configs, here's what the data format should look like:

Well this is new ! You have an OTA in-focus problem, why are we talking about Coma Corrector spacing ? Michael

I even tried measuring the guidecam height with digital calipers in an attempt to make tiny changes, but only a helical focuser gave best focus - with the commensurate spacing problem on the main imaging path I mentioned. Michael

You mean you can't focus with 57.5 mm but can with 55mm ? Michael

My OAG is AFTER the DSRL + MPCC, so that I can match the long guidecam light path caused by a Helical Focuser. No choice, stars are coma shaped, but PHD2 guides sub 1arcsec just fine. Not 100% sure, but I believe the Binning selection in PHD2 is to indicate that Binning has been selected in the guidecam driver. Michael

Your Nikon back focus is 46.5mm. Add an 11mm thick 48mm T ring Equals 57.5mm. MPCC MkIII backfocus to M48 is 57.5mm. Then add OAG to MPPCC. Does that work ?

(D300 has LiveView) If you're taking long exposures on dim DSO's then that initial shutter shake probably won't register. But if you're taking short exposures then mirror lockup is best. Michael

Mis post. "Show Us Your Body Bag" is in "The Lounge". Michael