michael8554

Hi vlaiv IMO you've over-complicated a simple explanation for someone struggling to understand how L is derived from RGB. Michael

What Camera ? Scope ? Is it on your Flats ? Is it on individual Lights ? Michael

Hi Andrew We covered that back on Dec 20th. Michael

Which part of my explanation is not for imaging sensors ? Michael

Having to go back 50 years to my Colour TV training ! If you passed midday sunlight through the Deep-Sky RGB filter you'd get equal amounts of R, G, and B passing through the filter. To derive L the software would mix RGB in the ratio 0.1B, 0.7G, 0.3R That matches the human eye response, mostly G with some R and B Michael

You all know about blanking off the DSLR viewfinder when taking Long Exposures, because extraneous light can get in there - right ? Found on the neckstrap, Canon provide a rubber eyepiece cover (A) that slides onto the viewfinder once the rubber and plastic eyecup is slid off. This cap isn't very secure, and often falls off into the long grass. I've not found a source for these caps, I often look out for Canon neckstraps in charity shops. So here's how to mod a Canon Viewfinder eyecup to provide a secure cover to the viewfinder. Replacement eyecups can be bought in the UK on eBay for about £2.35. (B) shows the underside, optionally remove the rubber cushion off the viewfinder eyecup. Cut a piece of black rubber or plastic about 0.5mm thick. IMPORTANT: now glue this to the underside, the face shown in (B), otherwise there will be a small light-gap under the lower end of the surround. (C) Finished item. Michael

If is in focus, 70% of L is made up of the G signal, and yes G will contain a small amount of R and B due to the G spectral makeup. Michael

PHD2 Guide Assistant measures PA and only complains if the error is greater than 5 arcmins. That's because the developers say that is good enough to guide with. So the 4.64arcmins in the screen shot is fine. And yes, changing the adjustment when you are that close is very tricky, another reason to stop while you're ahead. You only need to spend time getting a very low PA error if you're imaging without guiding. As I understand it, the recommended exposure times are based on the High-frequency Star Movement measurements., to prevent "Chasing the Seeing" conditions. That figure in the second screengrab is nearly twice the first. And until you gain experience, why would you doubt the recommended MinMo settings ? Michael

Luminance is very roughly 0.2R +0.7G + 0.1B. So if G is in focus, L may not look too bad. Michael

Software that freezes can usually be closed by Windows Task Manager. Right/Click on the Task and select "End Task". Michael

Might be in one of those links above, but default EQMOD Guide Rate is 0.1X , set it to 0.5X or higher. And before Cal, slew mount north at lowest speed until guidestar moves, to take up Dec backlash. Michael

He's not even Scottish..... Michael

The RP has a unique lens mount, so hopefully it came with the adapter to allow EF lenses to be used. You can then buy a M48 T-Ring An SCT to M48 Adapter to screw onto the back of the scope. An Intervalometer to sequence lots of short exposures without touching the camera shutter button, which causes wobbles. Without spending infinite amounts of money you will be restricted to short exposures, so starting at say10 seconds, experiment with longer and longer exposures until you notice Star Trailing, back off from there. Combine all those exposures in Stacking Software, which will give the effect of a single exposure the duration of all your short exposures added, so take lots ! Michael

fou adjective SCOTTISH inebriated; drunk. "his lordship gets them fou, steamin' fou"

I believe that guide camera pixel size is only relevant in the calculation of the guide Imaging Scale, which will determine the amount of wobble that +/- 0.2 pixel will transfer to the imaging camera. Michael

And you have the Slew Speed at a higher setting than default eg SPEED then 9 ? Is the mount tracking in RA (following star movement across the sky) ? The RA will start tracking if you skip Alignment, just enter Time and Date then MODE out to OBJECT. Then unlock Dec and RA and Relock after centring a star. Michael

You're not confusing the Menu Up/Down buttons at the bottom of the AudioStar with the mount Up/Down buttons higher up ? Michael

Sounds like the stop is broken in that direction. Try the other direction and centre at least one turn away from that stop. Michael

Hi Ed Years since I had an ETX125, so from memory here goes: There are RA stops in the base. Rotate it by hand, unclutched, one way until you hit a stop, Then rotate the other way until you hit the other stop. Then put it halfway between, but offset so that it's pointing north when the low end of the wedge is pointing north. Finder should be on top. Check it's in Polar mode on the handset. When you first switch on, the mount assumes you are pointing at true north, not Polaris. During Star Alignment, when prompted centre Polaris with the wedge Alt, and Az by nudging the tripod east or west. Then centre the next star with the handbox, and then ENTER. Michael

It all went pear-shaped when you switched to EQMOD with that low Guide Rate setting at 23:31 on the 11th......... Your guidescope focus could be better, get the HFD figure in the Star Profile to lowest figure, about 3 to 4 pixels Look at these from the PHD2 Developers: https://openphdguiding.org/phd2-best-practices/ https://github.com/OpenPHDGuiding/phd2/wiki/EQASCOM-Settings Recalibrate at Dec 0 after nudging north as in the best practices, run the PHD2 Guide Assistant and accept the settings, guide for 10 minutes without altering anything, close PHD2, and post that log. Michael

LLC has advised me that only early ETX90's are 9 Volts. Newer ones like his are 12V. All the other details are correct. Google Is Your Friend - NOT ! Michael

I'll have a look at your PHD2 GuideLogs. Looking at your EQMOD image, you have ASCOM PulseGuide Setting at x0.10. That's a very low rate which will make Calibration and guiding difficult. Set it to at least x0.5 (+/- 0.5 of Sidereal Rate) Michael

I never had banding on earlier Canon DSLR's, it only started with the 600D. Also I Dither, and load Bias subs as Darks in DSS. Michael

I occasionally use Windows Remote Desktop Connection with Mains Network Adapters, no need for a Wireless connection. Michael

Really need the PHD2 GuideLog to check your setup, the quality of the Calibration, and your guide settings. Regarding the Dec Backalsh, if your Dec balance is perfect then the mount is free to wobble from one end of the Backlash to the other. So balance Dec slightly off so that Dec is always at one end of its Backlash travel. And a slight PA drift in the same direction will help, PHD2 will cope. Michael