michael8554

Nudging North only takes a few seconds with the handset on lowest slew, looking for movement of the star on the PHD2 screen. Or using the PHD2 Manual Move in Tools menu with a large setting, say 5000. Michael

If PHD2 knows the RA and Dec and you've Calibrated at Dec 0, PHD2 will compensate for guiding at different Decs. And permanent setups can use the same Cal for months, so long as the kit or orientation of the guidescope isn't changed. If it doesn't then you have to Cal at every change of target. And knowing the Guide Rate gives a baseline for Cal and allows PHD2 to give help if say one axis is behaving differently. Michael

Anthony suggested a method of finding true north. It went off-topic with your meanderings into why it wouldn't work. You had the chance to say that the sun was south at local noon, but you didn't. Michael

Excuse me? In your reply to my post you disputed that it would work whenever the sun is up, all over the planet. I never mentioned the East-West shadow line, as it's not necessary to spend time doing it. Michael

"Solar noon happens at your location when the Earth's rotation brings your local meridian to the side of the planet that faces the Sun. From your perspective, the Sun, after having steadily gained altitude since sunrise, now reaches the top of the arch that its journey describes in the sky every day. At this moment, it appears due south, due north, or in the zenith position exactly above you, depending on your latitude and the time of year." Good enough ? Michael

You guys are making it so hard. Open your planetarium, check it's got your location correctly entered, fast forward to tomorrow. Click on the Sun Click on info Sun transits at 12:09 tomorrow. Get your stick ready and mark the shadow at 12:09 Simples. And yes, that worked good enough to permanently install my mount and have enough range to Polar Align. Michael

At this stage you're right, knowing RA, Dec, Guiderate, isn't a priority. How are you testing the cable for mount movement ? With the PHD2 Manual Guide buttons, with a big step entered say 5000 ? Michael

I'm not a EQASCOM user but I do offer PHD2 advice to EQASCOM users. Newbies aren't noticing that the Guiderate preset is very low, which gives PHD2 a hard time. I suggested to the PHD2 developers that they contact the EQASCOM developers with a view to upping the preset to a 50% or higher setting. We couldn't see any reason why that would be a problem. They have suggested that many times to EQASCOM but "it has fallen on deaf ears". I tried to post a comment myself but they are only accepting from Premium members. Any Premium member feel like picking up the nettle ? Michael

Looked at your Guidelog. Are you clearing Dec Backlash before Cal by nudging north until you see the star move ? That could stop the error messages. Yes should be better with 0.9 Guiderate and new Cal. Polar Alignment is good so Dec should only require minimal correction, particularly if you have balanced slightly heavy one way. Maybe keep the recommended high MinMo and reduce Aggr to 70 % to reduce the unwanted back and forth moves in Dec. Saw you playing with PPEC settings which is fine, but next time at 0.9 Guiderate let it run a goodly time on the default settings before playing. Getting there ! Michael

Interesting how PI sees the 1.2 sec image. The Screen Transfer Function window shows L at midpoint. So in PI the 1.2 sec image appears to be correct. The RGB values are also way different to my display of the image But at least the main window showing the Raw is very dim and doesn't look to be at midpoint, as I explained. Now on my 6D I dither and use the Bias as Dark, and the AV flats work very well and removes bunnies. But there's no point me arguing on which method is best, it's what works for you Bottletopburley that matters. Michael

Well I'm having to guess what your setup is since you haven't specified it. If you have a connection from the PC to the mount and a USB cable from the camera to the PC then I'm not sure why you need an ST4 cable. Michael

This business of midpoint exposure is tangled. On a Canon, the AV exposure viewed on the lcd screen is midpoint in the histogram, but that view has been processed and stretched from the Raw into a sort of jpeg, for viewing purposes. The Raw will look very dim if correctly viewed. So depending on your image editor or PC viewer software you may get varying results. So include me in that caveat, my image may not be accurate either! I'm not sure if I've already said, try an exposure that is midway on your Nikon's histogram. Michael

Thanks haitch, you should go into production with your 3D printed adapter! Michael

Hi Steve I think you've discovered what is covered again and again here on SGL. For reasons unknown, ST4 connection can be extremely flakey. What appears to be a perfectly good cable stops working, but a replacement fixes it. A bit like USB, works fine for some of us, others have endless problems for no apparent reasons. If you continue to get problems I would switch to an ASCOM EQMod type connection. Has the advantage of providing PHD2 with RA and Dec and Guiderate setting. Just saying....... Michael

Hi haitch The M range should be a good imaging camera for the reasons you mention, but seems to have some disadvantages. The EOS M mirrorless range has a unique bayonet size, different to the DSLRs, and SGL posters complain that the only T2 adapters have 26mm thickness instead of 10mm for DSLRs, so they are unable to use that short 18mm backfocus you mentioned to accommodate OAG, filter wheels etc - how have you managed this? Also could you list the M models that have full remote facilities, B shutter control etc, l over USB? Michael

Here's how the 1.2 sec image looks in PSP, the histogram is showing the Lum position : So way past the midpoint, and blue almost saturated (246 out of 255) So I'm not believing the statement in the link that the Canon AV setting is wrong. Michael

Did you run the Guide Assistant on the target? That would tell you the MinMo setting. Michael

Hi Steve What do you mean when you say "stopped guiding" ? The PHD2 graph has frozen ? PHD2 is issuing guide corrections but the mount isn't responding ? The guidecam isn't looping? Is this a ST4 or EQMOD setup? I didn't know there was a PHD2 cable snag error message. Can you post the relevant PHD2 Guidelog ? Michael

Guiding at high Dec should be easier, as closer to Dec 90, so the stars are "moving" much slower. But you may find the balance is wrong, And Guidescope to Main Scope Diff Flex may be worse. Michael

2 degrees 2 minutes 38.4 seconds west would be 00203W rounding up. That's if the seconds entry is 3 digits and the minutes two digits ? But I don't think the error is big enough to worry about. Michael

Do you have an autostar or an audiostar? Good thing using StarPatch instead of Meade ASU to update. Meade changed the Audiostar chips but ASU continued to load old firmware which bricked the audiostar......... Still not clear to me whether the LX85 uses a 497 or Audiostar and whether they are compatible. Michael

To save yourself a lot of work, take some flats without the Flattener. The spacing would only need to be approximate for this test, shove in whatever spacers you have. Michael

As were your initial long exposures, but they went out of focus on subsequent exposures. So it's important to take a series with the focuser locked tight. If stars are in focus then you can assume guiding isn't to blame and you can investigate focuser creep as the cause on the longer exposures. That focus difference may only be due to microns of creep. Michael

So the 80 ED and Flattener were okay on the DSLR, the only change is to the 168C ? Michael

I suggest you take a number of images with the focuser locked solid. Is your cooled camera fogging up? There is star elongation too, which is probably guiding - if a series of short exposures all have round stars then guiding is too blame. Michael