How should I control my DSLR?

[Baskevo]

Thank you, Jim. All of that was very helpful. I will try just using PHD2 first, and then SharpCap once I have that set up, and then I will move on to APT...

Soon, after you get more familiar with APT or most other imaging applications, you will start plate solving on targets. Huge improvement jump from manually aligning the mount.

Thanks,
Jim

So, what is the difference between plate solving and the GoTo system? I have heard that you don't need plate solving if you have GoTo... but I have also seen that a lot of people use plate solving with the AVX.

[JayTee]

Plate solving takes an image and determines the celestial coordinates of the center of that image. It's then tells your mount that it is pointed precisely at those coordinates. Now your mount knows exactly where it is pointed. And it can then figure out every other go to.

Cheers,
JT

[Juno16]

Goto is great for viewing targets with an eyepiece.

I would guess that plate solving is used by most imagers.

Like JT said, it takes an image of the sky and matches it to it’s database to determine where the scope is pointed and then syncs the mount to that position.

When using an imaging app like APT, you can send the scope to an area close to your intended target and plate solve to that target. The application will adjust the scope to the center of your target. You can then sync to the mount. The mount is tracking, so you are ready to image (of course, after focusing).

Thanks ,
Jim

[Baskevo]

Ah I thought that the GoTo system already did that... But cool I will look it up after I get everything else set up. Thank you, everyone! again, I appreciate it. I can't wait for tomorrow!

[Stuart]

I'm going to throw in my 2 cents worth. A couple of disclaimers--I do not know APT and I haven't used a DSLR in years. I use SGP for imaging, plate solving. PHD for guiding. To confirm polar alignment I use PEMPro, but only because I have it to PEC train my mount.

I recommend always reading the manual. I also always connect and test my equipment in the daytime to make sure all the parts are talking to each other.

Plate solving is really only useful if you are controlling your mount from the laptop. What it does is take an image and then exactly align your mount to that image (within limits of rotation). The GoTo only gets you to the area, but platesolving can get you to arcminute accuracy.

[bobharmony]

So, you're not connecting the camera to the mount at all? BTW, I'm using a ZWO camera. I can just connect that to my laptop with a USB-C cable, and then connect my mount separately with the USB mini cable? Interesting... I installed ASCOM because it was recommended by one of the programs (I think APT), but I had no clue how to set it up, and I didn't totally understand what it was for... I did not install the Celestron driver, but It sounds like it wouldn't have made a difference because I was using ST-4. Thanks for the tip, Jim!

Yes, to use ascom to guide the scope you need to connect the guide camera to the PC and use the mount with the USB mini-cable (if that is the connection on the bottom of the hand controller). PHD2 then connects to the camera to receive the guiding photos, and to the mount driver to send guide pulses to the mount. Download the Celestron Unified ascom driver.

You will see arguments from folks who swear by guiding with either the ST4 port or the ascom connection, to the point where they sometimes get defensive about it. The only benefit I can state for sure that the ascom solution has, is that you only need to calibrate PHD2 once, preferably with a star near the meridian and the celestial equator (close to DEC 0). Once calibrated, you can point the scope anywhere in the sky, and PHD2 will compensate for the different length of guide pulse needed at different declination values. If you use the ST4 port you should calibrate on something close to your target, and then image. If you slew to a second target using ST4, you should recalibrate on a star near the new target before imaging the new target.

Bob

[Baskevo]

So, you're not connecting the camera to the mount at all? BTW, I'm using a ZWO camera. I can just connect that to my laptop with a USB-C cable, and then connect my mount separately with the USB mini cable? Interesting... I installed ASCOM because it was recommended by one of the programs (I think APT), but I had no clue how to set it up, and I didn't totally understand what it was for... I did not install the Celestron driver, but It sounds like it wouldn't have made a difference because I was using ST-4. Thanks for the tip, Jim!

Yes, to use ascom to guide the scope you need to connect the guide camera to the PC and use the mount with the USB mini-cable (if that is the connection on the bottom of the hand controller). PHD2 then connects to the camera to receive the guiding photos, and to the mount driver to send guide pulses to the mount. Download the Celestron Unified ascom driver.

You will see arguments from folks who swear by guiding with either the ST4 port or the ascom connection, to the point where they sometimes get defensive about it. The only benefit I can state for sure that the ascom solution has, is that you only need to calibrate PHD2 once, preferably with a star near the meridian and the celestial equator (close to DEC 0). Once calibrated, you can point the scope anywhere in the sky, and PHD2 will compensate for the different length of guide pulse needed at different declination values. If you use the ST4 port you should calibrate on something close to your target, and then image. If you slew to a second target using ST4, you should recalibrate on a star near the new target before imaging the new target.

Bob

Awesome Thank you Bob! very helpful. I think this was my main problem... I wasn't connecting my mount correctly.

[Stuart]

I second the use of ASCOM for the use of PHD. I did both and ASCOM was way smoother. One fewer cable too!

[fatboy1271]

I haven't read through all of the posts here, skimmed many of them, but I trust the people responding to you. If you can make it to the *Valley with your gear one of these weekends I'd rather see you hang out with me for an evening and try to sort this out versus you jumping into a dark site with so many uncertainties. As you know I do have a six month old so that has to be part of the logistics; however, she's in bed by 7-7:30 and sleeps through the night. That means I just need permission from the wife... This is all spur of the moment thinking, but ideally have you get here late afternoon to dry run stuff in the daylight. Let me know your thoughts on it and if it sounds like something you'd want to try I'll ask for permission!

*For those of you older than say 40 and not from SoCal, the Valley that I'm referring to is THE Valley that Valley Girls comes from

[Baskevo]

Fatboy, I'd be willing to make a trip out there! I was definitely going to make sure I had everything setup before I went to the dark site, and I knew how to setup and tear down my equipment and use the software before the trip. I probably won't make it this month, as there's still a lot to learn and I have a lot going on with school (I'm taking all of my upper division courses right now, and I'm taking an LSAT course to apply for law school soon).

I appreciate the offer! I'd appreciate some advice on the software and everything, so maybe I can make it out there sometime in the next few weeks, if you can get permission lol

[fatboy1271]

Fatboy, I'd be willing to make a trip out there! I was definitely going to make sure I had everything setup before I went to the dark site, and I knew how to setup and tear down my equipment and use the software before the trip. I probably won't make it this month, as there's still a lot to learn and I have a lot going on with school (I'm taking all of my upper division courses right now, and I'm taking an LSAT course to apply for law school soon).

I appreciate the offer! I'd appreciate some advice on the software and everything, so maybe I can make it out there sometime in the next few weeks, if you can get permission lol

Awesome! Congrats on having focus for what you want to do in life!!! Best of luck with your studying.

Now, on the important stuff!!! Haha! Since our equipment is so similar I'm going to take pictures of everything I have. I think it will be helpful. You'll see all the cables you need. I have everything zipped tied "perfectly." I can use the AVX tripod at any height and the cables stay put. I can slew to any part of the sky I'm able to image in and the cables don't tangle or cause my setup to fall into the pool...

We're going to a wedding on the Queen Mary tomorrow night and staying the Mother-In-Law's so I might not be able to post pictures until Monday. Let's definitely plan a backyard star party! It shouldn't be an issue and my wife would rather me have people over then me going out.

[Baskevo]

Thanks, Fatboy! It's nice to have a plan.

That would be helpful, I appreciate it! Whenever you have a chance. Thanks man

[Baskevo]

Had another horrible night tonight I think I kind of almost had it? I have a feeling that it has something to do with my equipment, and that it shouldn't be this hard...

I tried to do only PHD2 tonight. I was already in focus, aligned, I installed the Celestron ASCOM driver, and I was able to control my mount from my computer, and I was happy. I was set up inside my room, took it outside, and everything was looking fine. I deleted the equipment settings I made the other night, and started from scratch with the PHD2 best practices and the user manual up and ready.
I was able to get the camera calibrated just fine. So, I decided to try a drift alignment.

I was roughly polar aligned, as usual, which usually gets me around 2 minute exposures without guiding. I thought I was pretty close, but then according to PHD2, I was pretty off the mark. The display graph was all over the place (I noticed it during the drift alignment f, but it was off beforehand too). I wouldn't have known it was supposed to look like that before I watched some videos on it. The RA curve was no where near the center, and the DEC curve was overshooting like crazy...

I increased the exposure time to 3 sec, decreased the gamma, and went through the guide assistant. I did what it recommended and it made it worse... I literally spent like 6 hours trying to figure it out, reading the troubleshoot guides, watching videos, etc. I could not figure it out.

I'm going to submit my logs, and hopefully get some answers... I'm scared its my mount...

[Juno16]

Sorry to hear about your night. We all know how it feels. Pretty darn cruddy.

Heck, if I could have gotten 2 minute exposures with my AVX, I probably would never have gone to guiding!

It’s probably not as bad as you think. Submit your logs and someone here will have some ideas.

Thanks,
Jim

[seigell]

I was roughly polar aligned, as usual, which usually gets me around 2 minute exposures without guiding. I thought I was pretty close, but then according to PHD2, I was pretty off the mark. The display graph was all over the place (I noticed it during the drift alignment f, but it was off beforehand too). I wouldn't have known it was supposed to look like that before I watched some videos on it. The RA curve was no where near the center, and the DEC curve was overshooting like crazy...

Make sure that you entered the correct Guide Camera Model and Pixel Dimensions and (especially) the Guide Scope Focal Length (its not asking for the Imaging Scope).

Also make sure that your AVX is set "Tracking: Sidereal", "Tracking: North", and "Tracking: ON" (depending on your Star Alignment routine or lack thereof, Tracking can start as OFF).

Then, look at the Units on the PHD2 Tracking Graph - it scales to the smallest that allows the Trace to remain on the Graph. It could be that you see a "Seismograph Trace" that is only 1 arc-sec Peak-to-Peak.

On top of it all, show patience - AutoGuiding often takes a few nights to resolve. Stick to the Basics, and listen to the Guiding Assistant output. And you really want to let each Change of Parameter to run for 5-10 minutes in order to "Settle In" (especially if initial conditions include any Stiction or Backlash).

I'm scared its my mount...

Since you performed successful PHD2 Calibrations right from the start, it's unlikely anything DIRE with your Mount.

[Baskevo]

Sorry to hear about your night. We all know how it feels. Pretty darn cruddy.

Heck, if I could have gotten 2 minute exposures with my AVX, I probably would never have gone to guiding!

It’s probably not as bad as you think. Submit your logs and someone here will have some ideas.

Thanks,
Jim

Lol 2 minute exposures only AFTER setting up for an hour, running the ASPA 5 times in a row

I think you are right.

Make sure that you entered the correct Guide Camera Model and Pixel Dimensions and (especially) the Guide Scope Focal Length (its not asking for the Imaging Scope).

Also make sure that your AVX is set "Tracking: Sidereal", "Tracking: North", and "Tracking: ON" (depending on your Star Alignment routine or lack thereof, Tracking can start as OFF).

Then, look at the Units on the PHD2 Tracking Graph - it scales to the smallest that allows the Trace to remain on the Graph. It could be that you see a "Seismograph Trace" that is only 1 arc-sec Peak-to-Peak.

On top of it all, show patience - AutoGuiding often takes a few nights to resolve. Stick to the Basics, and listen to the Guiding Assistant output. And you really want to let each Change of Parameter to run for 5-10 minutes in order to "Settle In" (especially if initial conditions include any Stiction or Backlash).

I'm scared its my mount...

Since you performed successful PHD2 Calibrations right from the start, it's unlikely anything DIRE with your Mount.

Yeah I think my main problem was setting guide scope focal length as the aperture I feel dumb! lol

Thanks for the advice, I will try these tonight after running through the advice by the PHD2 forum. It's really nice to hear it's nothing super off with my mount! The mount was very expensive (to me) but I know it's entry level when it comes to AP.
Thank you for the help, guys! I will keep you updated.

[seigell]

Lol 2 minute exposures only AFTER setting up for an hour, running the ASPA 5 times in a row

Don't get discouraged.
Many of us regularly expend 60-90 minutes in Setup and Calibration EVERY Time that we go out (often on top of 1-2hrs driving to get to a "reasonably dark" site). And still can't count on as good or better than 2-minute Exposures without AutoGuiding (many with $5K invested autoguide for anything of any exposure length).

It is a shame that these challenges plague you with a New Moon Weekend approaching, but you can always work on your "Dark Skills" (Setup, Autoguiding, Polar Alignment, Plate Solving) while the Baleful Moon is glaring down on you mid-month, too.

So, for this coming weekend, maybe just setup as best you can and capture some of those 90sec-2min Exposures (lots of them). Then impress yourself and energize your enthousiasm for the AP Hobby with the Final Image that you can Stack and Calibrate and Post Process from such humble efforts.
(Ouch: Did you realize that there is at least as much learning curve and potential frustration in the Image Processing part, too?? )

[Baskevo]

Lol 2 minute exposures only AFTER setting up for an hour, running the ASPA 5 times in a row

Don't get discouraged.
Many of us regularly expend 60-90 minutes in Setup and Calibration EVERY Time that we go out (often on top of 1-2hrs driving to get to a "reasonably dark" site). And still can't count on as good or better than 2-minute Exposures without AutoGuiding (many with $5K invested autoguide for anything of any exposure length).

It is a shame that these challenges plague you with a New Moon Weekend approaching, but you can always work on your "Dark Skills" (Setup, Autoguiding, Polar Alignment, Plate Solving) while the Baleful Moon is glaring down on you mid-month, too.

So, for this coming weekend, maybe just setup as best you can and capture some of those 90sec-2min Exposures (lots of them). Then impress yourself and energize your enthousiasm for the AP Hobby with the Final Image that you can Stack and Calibrate and Post Process from such humble efforts.
(Ouch: Did you realize that there is at least as much learning curve and potential frustration in the Image Processing part, too?? )

Thanks for the encouragement, Seigell. To be honest, I am not as discouraged as I am stubborn I get in these spouts of "I can't stop until I figure it out." It runs in my family.

I'm going to try again tonight, hopefully I will have some better luck, and if I can't figure it out by next weekend, I think you've got the right idea (ignore the auto guiding until the middle of the month, giving the AP bug some juice).
I never mind a learning curve! Even if it is cold outside at 2 am The processing doesn't seem nearly as bad haha

[Baskevo]

I got this message today after posting last nights logs on PHD2 forum:

If we look at the 1h19m guiding session starting at 02:00 and ignore the few places where some of the gear was obviously flopping around, we can see you’re already in the ballpark. The total guiding RMS was 1.3 arc-sec (that’s our typical estimator of guiding performance) and the RA and Dec values were quite similar. So even with the problems discussed earlier, you were already guiding at a decent level and should be able to get more improvements without too much more work.

Almost there!!

[seigell]

The total guiding RMS was 1.3 arc-sec ... and the RA and Dec values were quite similar.
Almost there!!

That's GOOD. 1.3 arc-sec Guiding is about as good as your Equipment can produce - and about as good as your Imaging Rig can Capture - and likely about the Limit of Seeing for your Skies.

Now, your goal should be to consistently repeat that AutoGuiding performance.

And then you can move along to knock out other aspects of your AP Imaging Setup and Workflow...