Need advise regarding mount for DSO astrophotography

[iapa]

2 minutes ago, Charming Potato said:

I'm not sure if it transmits data over that port. I've tried looking into the manual but can't find any info. Searching through internet I couldn't find anyone who uses it with a cable. I guess I'll just have to figure out a way to connect it somehow through Bluetooth or Wifi.

Pg 54 of manual says it is a high speed USB port.

Apparently Snapbridge can be used for shutter control: https://www.dpreview.com/forums/thread/4631473

 

[iapa]

40 minutes ago, Charming Potato said:

3. What other cables would I need other than a USB -> RJ12 to connect the mount to a computer?

The mount is controlled via the USB port

Yo do not need the use the ST4 port for guiding. I believe AstroBerry support PHD2 for guiding.

[Charming Potato]

18 minutes ago, iapa said:

On pg4 of the user manual it states:

Fits standard 3/8 and 1/4 inch tripod/quick release brackets

 

I don't see that in the manual on page 4: https://inter-static.skywatcher.com/downloads/sagti_manual_rev8c.pdf

I believe my question wasn't clear. What I wanted to ask was that do I need a special plate/equipment to mount my camera to the head of the mount?

[Charming Potato]

12 minutes ago, iapa said:

Pg 54 of manual says it is a high speed USB port.

Apparently Snapbridge can be used for shutter control: https://www.dpreview.com/forums/thread/4631473

 

That's perfect, thank you.

 

9 minutes ago, iapa said:

The mount is controlled via the USB port

Yo do not need the use the ST4 port for guiding. I believe AstroBerry support PHD2 for guiding.

So that means it can be done without the cable? Over WiFi I believe?

[iapa]

1 minute ago, Charming Potato said:

I don't see that in the manual on page 4: https://inter-static.skywatcher.com/downloads/sagti_manual_rev8c.pdf

I believe my question wasn't clear. What I wanted to ask was that do I need a special plate/equipment to mount my camera to the head of the mount?

It means that the quick release that you have on your current camera tripod fit

[iapa]

1 minute ago, Charming Potato said:

That's perfect, thank you.

 

So that means it can be done without the cable? Over WiFi I believe?

PHD2 will send guide control via the usb port on the mount

[Charming Potato]

2 minutes ago, iapa said:

PHD2 will send guide control via the usb port on the mount

Oh, I'm dumb. It was right in front of me and for some reason my brain decided to ignore it. Thank you so much! I think I will go ahead with this setup.

[Elp]

Camera to mount: the SAGTI should have provision in the box to mount, I know the Star Adventurer Pro package does. If not, some sort of vixen dovetail bar will mount directly into the saddle of the mount, then you need the dovetail bar to have a 1/4 inch screw thread or you can use a 1/4 inch bolt from below the dovetail to attach a ball head mount so you can orientate the camera to point anywhere. If you're going to use the goto of the mount it's simpler, the camera can be bolted to the dovetail bar lens pointing parallel to the bar, the mount will take care of the pointing once polar aligned. The ball head or some sort of lockable low profile pan/tilt head will give you some fine adjustment of pointing the camera as you won't be using plate solving, so you'll need to use some trial and error by taking preview images before making a run.

Battery: I use the Celestron Lithium LT (astro retailer) and a Talentcell 72W 100WH (Amazon), the latter at the moment seems to last much longer than the LT, and is cheaper.

Edited June 22, 2023 by Elp

[iapa]

There a u-took video by Saramatchastro using a star tracker and DSLR

[Charming Potato]

So I got my SA GTi today (yay). Now I tried assembling the mount with everything attached, and I am having trouble balancing it in DEC axis. In RA it is okay, but when I tilt the camera 90 degrees on the DEC, it becomes weight side heavy. I have tried making the weight go as far up as possible, but it doesn't have the capacity to go above 70% as then it starts to hit the polar alignment dial and the body of the mount.

I believe it might be the attachment I have for the camera to connect to the mount. I got this quick release plate: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p9348 . It doesn't perfectly sit in the mount's mouth (?) and I think this might be the reason why I cannot get it to balance in the DEC axis? It is also too low so the camera body hits the tightening screw that holds the plate onto the mount, so I have to put the camera not parallel to the plate.

Maybe I am doing something else wrong?

EDIT: I read @Elp's comment after I had ordered everything, so I'm more and more certain it is the attachment that is holding the camera. If that is the case, is this a good dovtail plate? https://www.teleskop-express.de/shop/product_info.php/info/p237_TS-Optics-Dovetail-Mounting-Bar-Vixen-style---100-mm-slotted-hole-and-1-4--screw.html

Edited June 26, 2023 by Charming Potato

[Elp]

The counterweight is to balance the RA. Typically you balance the RA first so it doesn't move when you have the RA axis loose and rotate your setup around the RA and let go. Once that's done you return the RA to home position (imaging load pointing front on top of mount in line with mount with counterweight shaft pointing perpendicular at the ground (with altitude angle)), tighten the RA clutch then loosen the Dec clutch and see how that moves. You usually need a longer dovetail bar to be able to move the imaging load forward or back to balance in Dec. If your load is wide you have to counterweight balance your equipment (as an example camera to one side, guidescope to the other) so when you rotate around the declination and the clutches as loose the load shouldn't move. Once done return back to home position and tighten declination clutch. You can check the Ra again but it's normally fine.

Congrats on the purchase.

Edited June 26, 2023 by Elp

[Elp]

Any dovetail plate will do really, I tend to get ones with multiple holes, slots or threads because when you mount a camera body and heavy lens you can use some of them with bolts to act as physical stops to stop the camera from rotating when it's tilted at an angle. I don't know why camera manufacturers don't put multiple fixing holes under their cameras for this purpose.

[Charming Potato]

2 hours ago, Elp said:

The counterweight is to balance the RA. Typically you balance the RA first so it doesn't move when you have the RA axis loose and rotate your setup around the RA and let go. Once that's done you return the RA to home position (imaging load pointing front on top of mount in line with mount with counterweight shaft pointing perpendicular at the ground (with altitude angle)), tighten the RA clutch then loosen the Dec clutch and see how that moves. You usually need a longer dovetail bar to be able to move the imaging load forward or back to balance in Dec. If your load is wide you have to counterweight balance your equipment (as an example camera to one side, guidescope to the other) so when you rotate around the declination and the clutches as loose the load shouldn't move. Once done return back to home position and tighten declination clutch. You can check the Ra again but it's normally fine.

Congrats on the purchase.

Thank you! That helped and it seems to be balanced on both axis now! Luckily I got my portable power station as well today (Talentcell 72W 100WH as you suggested), so I was able to connect to test if everything works and it seems good to go! I tried going towards a target just to test, but the goto was WAY off of it, and I believe that is because I didn't polar align it yet? It's day time, and unfortunately there seems to be cloudy skies throughout the week, so won't be able to do anything this week, but just wanted to test.

Two things I wanted to confirm as I couldn't find them in the manual:

1. Do I need to tighten the RA/Dec clutches after they're balanced? Like tightened to the point where I cannot manually move them and let the motors do the work?

2. Attached picture is what I believe should be the "home" position of the mount. Is this correct?

EDIT: One more thing, let's say my latitude is 65.123123, that means I need to skew the polar wedge to 65 on the polar scale, right? If that is the case, is this considered a low or high altitude? Because it says to equip the counter weights in a different position if your latitude is low. I tried finding it out but couldn't understand it.

Edited June 26, 2023 by Charming Potato
Added another question

[Elp]

1. Yes tighten the clutches, they don't need to be rock solid tight, just hand tight.

2. Home position is correct, when you're outside the front of the mount will be pointing to true north/Polaris, once polar aligned the camera will be centred on Polaris.

3. Wedge adjusted to your latitude, on some separate EQ wedges I've used their latitude scale has been backward (illogical so they were 90-latitude). You'll know when you're outside, looking down the side up at polaris you'll either be near or far.

4. Set up your counterweights as per Ra and Dec balancing. They may be on about so the weights do not hit your mount or tripod.

5. You can try the goto indoors if you point it to true north and have the altitude set correct, issue a goto and cross reference it's rough position to a star atlas like stellarium, just make sure the date time, daylight savings time, UTC time offset and location are correct (all these relate more to a traditional hand controller), I'm guessing it'll read your settings off your phone or something if you're using a phone app (not sure how you control it on a SAGTI).

[Charming Potato]

26 minutes ago, Elp said:

1. Yes tighten the clutches, they don't need to be rock solid tight, just hand tight.

2. Home position is correct, when you're outside the front of the mount will be pointing to true north/Polaris, once polar aligned the camera will be centred on Polaris.

3. Wedge adjusted to your latitude, on some separate EQ wedges I've used their latitude scale has been backward (illogical so they were 90-latitude). You'll know when you're outside, looking down the side up at polaris you'll either be near or far.

4. Set up your counterweights as per Ra and Dec balancing. They may be on about so the weights do not hit your mount or tripod.

5. You can try the goto indoors if you point it to true north and have the altitude set correct, issue a goto and cross reference it's rough position to a star atlas like stellarium, just make sure the date time, daylight savings time, UTC time offset and location are correct (all these relate more to a traditional hand controller), I'm guessing it'll read your settings off your phone or something if you're using a phone app (not sure how you control it on a SAGTI).

Thank you so much! I will try adjusting to north inside see if goto is working as intended.

EDIT: I pointed it roughly towards true north, and now goto seems to be going in the right direction! I can't wait to try it out once this thunderstorm goes away! Thank you @Elp and everyone else here for all the help, I really appreciate it!

Edited June 26, 2023 by Charming Potato

[iapa]

Try this

 

Edited June 27, 2023 by iapa