Hardware and software advice needed for upgrading to guided imaging

[ianpwilliams]

OK, might as well work my way through that guide and post questions as I go along, if anyone can help...

Matching the pixel scale of the guider and imager - I have no idea how to work this out manually, so I tried using the Imaging Toolbox. I put "1100D" and "130P" into it (there is no 130PDS but I assume it's the same, just a different focusser), but I'm not sure what I do now. Also, there doesn't seem to be an option to enter the guide cam, but surely that is required seeing as that it part of the formula?

Flexure - this guy talks about this a lot and it's obviously an issue. He talks about the various causes etc, but I'm not sure what else I can do other than what I planned, which is to run the cables down the telescope tube, leaving enough leeway so that the cables naturally head to the tube rather than having lots of leeway so they can flop about, but not so that they are pulled down tight, and then gaffer taping them to the tube, then running to the mount/laptop. And obviously I'll attach the Orion guide scope to the 130PDS nice and tightly. But apart from that, what else can I do? He does go on to say that with a short focal length the two scopes don't have to be perfectly aligned, which I believe someone here mentioned too?

Camera non-orthogonality and digital callipers - so I really need to worry about this stuff right now? I'm not sure where I would begin.

Drift alignment - he says "As stated previously, I find that a polar scope alignment works really well for my short-focal length imaging, but the longer your focal length, the more critical a good Polar Alignment becomes, and thus part of the reason why imaging at long focal lengths is hard.". If I attempt to drift align (and if I'm going down the ASCOM route then I might as well at least try seeing as PHD2 supports it) then will that possibly allow longer sub lengths?

Balancing the mount - he says to balance it "east-side heavy". I'll admit that previously I was just going for a balanced setup that wasn't heavy either way, because I had my markers on my scope dovetail etc so I was able to achieve a balanced setup quickly every time. But if I was to go slightly east-heavy, then wouldn't that mean that I would have to make weight adjustments every session depending on where my target was, because the scope would obviously be in different positions and pointing in different directions?

Taking darks (not guide camera darks which I know I will have to take, but imaging camera darks) - assuming I eventually manage to take reasonable-length sub lengths, maybe 5 minutes say, I guess I would have to take darks of the same length wouldn't I? It's just something that occured to me the other day, which could make a long imaging session a whole lot longer.

So taking into account the fact that I'm buying the Hitec cable, please can someone remind what the programs are which I'll be using? Obviously PHD2 for guiding and apparently polar alignment refinement and drift aligning. Then would it be that Circ program for choosing a target? And BackyardEOS for controlling the imaging camera? The fewer programs the better I think, and the less power-hungry programs the better, because I'll always be concered about the laptop battery.

I think that's all my questions for now. Hopefully once all the stuff arrives I can run through all the various steps in that guide indoors in the daytime and just see if any other questions come up. I'm guessing it'll probably take a month or so just to work out what I need to do and how to do it, but that's just the way it is.

[ianpwilliams]

Did you actually get the altitude bolt right in before testing it adjusted to 55.94 degrees?

I couldn't get it in because the polar scope was blocking it. It was physically impossible because of the handle. It's not a major concern though, I can live without them. Just would have been a bit less painful on the hands than the original bolts.

[Davesellars]

I found that with my NEQ6 but it has a simple solution  move the EQ mount to a more favourable angle put the bolt in... take off the polar scope cover if it helps as it's a chunky thing...

[ianpwilliams]

I did take the polar scope cover off but even that didn't help. The bolt just tilted the mount back to the point where I couldn't turn the handle any more. Maybe I'm doing something wrong...I'll give it another go at some point, but it's not a major issue as I've got far bigger things to think about relating to guiding!

[Thalestris24]

Hi

I'm at 55 32 26 which is 55.877 deg and although the latitude bolt goes in a long way there is still a bit of thread left (maybe 2mm). If it comes to it, you can always raise the front leg a tad. The clutch on the upgrade bolt adjuster should give you some wriggle room anyway. Don't go by the latitude scale!

Louise

[DanL]

Not quite clear if problem is actually getting the bolt in or its in place but protrudes to far. Just in case you haven't tried it and it's the handle I'm thinking of, you sort of need to ratchet it in by twisting round as far clockwise as you can go, then thumb the red button to release the handle and swivel it back around and release so it re-locks and you can twist the bolt around again.

Apologies if that's not the issue but from the last few comments that is what I imagined to be the problem.

[emoji4]

[ianpwilliams]

Yes good point, maybe I wasn't using the ratchett bit properly, I'll give that a try.

In the meantime if anyone can help with any of my questions that would be great. I've ordered the EQDIR cable so I'm definitely going to try the ASCOM route.

[D4N]

With regards to darks yes they must be the same exposure, gain and temperature as the light frames. The last part is what causes the most problems if you are using a DSLR as it is very difficult to match the temperatures of the light frames let alone the darks.

Another option is not to use darks and to just use a bad pixel map instead.

/Dan

Sent from my iPad using Tapatalk

[Starfisher]

OK, might as well work my way through that guide and post questions as I go along, if anyone can help...

Matching the pixel scale of the guider and imager - I have no idea how to work this out manually, so I tried using the Imaging Toolbox. I put "1100D" and "130P" into it (there is no 130PDS but I assume it's the same, just a different focusser), but I'm not sure what I do now. Also, there doesn't seem to be an option to enter the guide cam, but surely that is required seeing as that it part of the formula?

Flexure - this guy talks about this a lot and it's obviously an issue. He talks about the various causes etc, but I'm not sure what else I can do other than what I planned, which is to run the cables down the telescope tube, leaving enough leeway so that the cables naturally head to the tube rather than having lots of leeway so they can flop about, but not so that they are pulled down tight, and then gaffer taping them to the tube, then running to the mount/laptop. And obviously I'll attach the Orion guide scope to the 130PDS nice and tightly. But apart from that, what else can I do? He does go on to say that with a short focal length the two scopes don't have to be perfectly aligned, which I believe someone here mentioned too?

Camera non-orthogonality and digital callipers - so I really need to worry about this stuff right now? I'm not sure where I would begin.

Drift alignment - he says "As stated previously, I find that a polar scope alignment works really well for my short-focal length imaging, but the longer your focal length, the more critical a good Polar Alignment becomes, and thus part of the reason why imaging at long focal lengths is hard.". If I attempt to drift align (and if I'm going down the ASCOM route then I might as well at least try seeing as PHD2 supports it) then will that possibly allow longer sub lengths?

Balancing the mount - he says to balance it "east-side heavy". I'll admit that previously I was just going for a balanced setup that wasn't heavy either way, because I had my markers on my scope dovetail etc so I was able to achieve a balanced setup quickly every time. But if I was to go slightly east-heavy, then wouldn't that mean that I would have to make weight adjustments every session depending on where my target was, because the scope would obviously be in different positions and pointing in different directions?

Taking darks (not guide camera darks which I know I will have to take, but imaging camera darks) - assuming I eventually manage to take reasonable-length sub lengths, maybe 5 minutes say, I guess I would have to take darks of the same length wouldn't I? It's just something that occured to me the other day, which could make a long imaging session a whole lot longer.

So taking into account the fact that I'm buying the Hitec cable, please can someone remind what the programs are which I'll be using? Obviously PHD2 for guiding and apparently polar alignment refinement and drift aligning. Then would it be that Circ program for choosing a target? And BackyardEOS for controlling the imaging camera? The fewer programs the better I think, and the less power-hungry programs the better, because I'll always be concered about the laptop battery.

I think that's all my questions for now. Hopefully once all the stuff arrives I can run through all the various steps in that guide indoors in the daytime and just see if any other questions come up. I'm guessing it'll probably take a month or so just to work out what I need to do and how to do it, but that's just the way it is.

if your 50mm guidscope has a FL of 162 and using the ASI your pixelscale will be 4.84"/pixel (mine 50mm guidescope is 50mm/320mm FL , just for info)

your 130PDS with 1100D would give 1.16"/pixel.

if you want to match them , you need a x4 barlow in your guiderscope. so you would basicly guide at the same fl than your 130PDS

if you like counting stuff like that , here is a nice link you can also give in own numbers :   http://www.12dstring.me.uk/fov.htm

happy i could help,

[Thalestris24]

Hi

With sub-pixel guiding there's no need to match pixel scales. You will be limited by your seeing anyway. I expect the op will likely want to put a coma corrector / focal reducer on his 130pds which will give an effective focal length of 585mm. A finder guider worked fine with my 750mm 150pds. Putting a Barlow in your guide scope isn't a good idea...

Louise

[ianpwilliams]

I'm already using a coma corrector with my 130PDS actually, so hopefully it might all be good then.

[Thalestris24]

I'm already using a coma corrector with my 130PDS actually, so hopefully it might all be good then.

If it's a Skywatcher reducing one? Otherwise you'll likely still be imaging at your native focal length i.e. 650mm but that's still ok

Louise

[ianpwilliams]

It's the Skywatcher 0.9x one from FLO.

[Jokehoba]

Hi,

After reading through this lengthy thread, I am glad you have decided to use ASCOM. It does simplify things. I believe my set up is very similar to what you are building (albeit now I have a DIY observatory). Here is how I used to set up:

1. Level the mount and point it to Polaris.
2. Connect EQ Direct cable from mount to laptop. (Note, I use pulse-guiding through EQMOD so no need to connect ST-4 cable.)
3. Connect wireless gamepad receiver and switch on gamepad (replaces Syntrek/Synscan handbox and programmed in EQMOD)
4. Connect mouse (easier to use than the laptop pad)
5. Start up laptop. Load StellariumScope (starts Stellarium too) and connect to mount in EQMOD.
6. Polar align using procedure in EQMOD and the mounts polarscope.
7. Once happy with PA, attach scopes, cameras and remaining cables. Balance everything.
8. Start up APT and PHD2.
9. Select a star to align to in Stellarium, and slew to it.
10. Using a combination of finderscope and APT's Liveview, centre and sync on the star.
11. Repeat 9-10 at least twice (i.e., 3-star align) in the region to be imaged. I'd use one of the alignment stars to perform a fine focus.
12. Slew to target and click Shoot in APT to see whether it's framed correctly. Adjust target placement in the FoV.
13. Choose a guide star in PHD2 and calibrate.
14. Once guiding, start imaging! Typically I use a light frame plan in APT of 5mins at ISO800 (but it does depend on many factors). I only store images to the PC, RAW and JPG, and have set up a meaningful auto-filenaming regime (saves so much time sorting images after the session).
15. As I am impatient, I set up Deep Sky Stacker Live to monitor the image folder so I can get an idea of what to expect in the stack.
16. Once all light frames done, I collect about 30 flat frames and then would pack up. (I used previously acquired master dark/master bias frames, according to temperature.)

Probably missed something...

It took about 30-45 mins get set up and start imaging (and about 20mins to disassemble). It may look like a lot of steps but as others have said, once you've done it a few times it is very straightforward. I'll also add that I have always used mains power so battery life has never been a worry.

John

[ianpwilliams]

Thanks John that's great! I have my own step-by-step for unguided imaging which I've been using, so now I can work on creating a new version for a guided setup based on your information.

And I'm expecting it to take an hour to set up, certainly to begin with, and maybe just as long even once I'm well practiced. But hopefully it'll be worth it in the end!

[ianpwilliams]

One question, when you say:

1. "Using a combination of finderscope and APT's Liveview, centre and sync on the star."

I've been told that I will have to replace my finderscope with the guidescope, and APT's Liveview would be coming through the guidescope. So the only other way I could check that the star was centered would be using the live view of the camera?

[D4N]

Yes use your imaging camera, the target star should be on that. If not you may need to consider either a visual finder or plate solving.

Plate solving is a pain to set up but once it is working there is no need to star align anymore, just slew and let it sync for you.

/Dan

Sent from my iPad using Tapatalk

[ianpwilliams]

I'm trying to think about ways where I can try to save time during setup. When I did my previous unguided imaging I used a method which saved me a lot of time. I did the following, but only once:

I put the tripod down, facing North, legs fully extended, attached the accessory tray to brace the legs, then made sure that the tripod was level all three ways using a spirit level and adjusting the lengths of the legs. I put the mount in the Home position, put on the tripod, attached the weights, then attached the scope (with camera attached). I unlocked the RA and rotated the RA so that the weights and scope were side by side, adjusted the weights until it was balanced, and then put marks on the weight bar. I then unlocked the DEC, rotated the DEC until the scope was parallel to the ground, and then loosened the tube rings and rotated the scope so that it was balanced, then tightened the tube rings, then put marks on the dovetail until I had balance. Then I put marks on the concrete slabs that the tripod was standing on. Then I adjusted the Alt and Az bolts so that I could see Polaris through the polarscope. Then I took everything back inside, leaving the legs at the same length.

In future sessions I was then able to carry the tripod outside with mount attached, and I knew that if I put the tripod feet where the marks on the ground were then my mount would be level. Also, I knew that when I put my weights and scope onto the mount that as long I put the weights where the marks were and as long as I attached the scope to the dovetail where the marks were, that the scope would be balanced through both RA and DEC. And I could always see Polaris in the polarscope straight away. This saved me a lot of time every session.

However, the concrete slabs have since gone, so I need to set up in another part of the garden (see below), and I need to decide whether it will be feasible to do a similar thing for a guided imaging setup.

In these photos of my shared garden (the first one taken standing right next to the three-storey house, the second one taken from my bedroom window), I used to be set up in the far left corner, so the tree sometimes blocked the best targets:

So I now need to set up in another part of the garden. I was thinking of setting up by the plastic swings on the right, although that three is still a bit of a problem even from there:

and the house is pretty tall too:

So taking all of this into account, I need to decide whether to try to have a "permanent" setup like I did above (which I could do by hammering tent pegs low enough into the ground that they didn't interfere with lawn mowers etc, but so that the tripod feet had markers to rest against), or whether to set up from scratch every time, which would be a lot more time consuming, but which would mean that I would always be able to go to a part of the garden where my target would be easily accessible (although the garden is quite slanted overall so levelling would undoubtedly be a pain every time).

I've read about how for imaging you are actually supposed to be slightly "east-heavy", but I'm not sure what that means exactly because it seems to be based on which side of the mount the scope will be after slewing to the target. But then how can you predict where the scope will be once the mount has slewed to the target? The scope could be pointing at a target that was high in the east for example, but the scope could point at that target while being on the east or west side of the mount. So I'm not sure how that works. If I need to balance the scope to be "east-heavy" then I guess I will have to set up from scratch every time?

[ianpwilliams]

In the meantime I've tried to create a new step-by-step for myself for a guided imaging setup:

Primary Setup

1. Place the tripod down without the legs fully extended, with the “N” leg facing North

2. Attach the accessory tray to brace the legs

3. Ensure that the tripod is level all three ways using a spirit level, and by adjusting the length of the legs

4. Put the mount on the tripod with the weight bar pointing to the ground

5. Attach the weights then the telescope to the mount

6. While supporting the scope, unlock the RA clutch, rotate the RA to 90 degrees, and then lock the RA clutch

7. Tilt the RA left and right, and feel for imbalance. Adjust the position of the weight until balance is achieved. For imaging, leave the balance with a slight bias East heavy

8. While supporting the scope, unlock the DEC clutch, rotate the DEC so that the scope is roughly parallel to the ground and check for imbalance.  Loosen the dovetail rings and rotate the scope in the dovetail until balance is achieved, then tighten the dovetail rings

9. Return the mount to the “Home” position

10. Adjust the altitude bolts on the mount until you can see Polaris through the Polar Scope

Polar Alignment (EQMOD_ASCOM, PolarFinder App)

1. Remove the top and bottom caps from the front Polar Scope

2. Rotate the Dec (and telescope) so that the telescope is side-on to Polaris, facing over your shoulder (so you can see through the polar scope)

3. Connect the EQDIR cable from the mount to the laptop

4. Connect PS2 controller to the laptop

5. Connect mouse to the laptop (or use the laptop mouse button)

6. Bring the laptop out of sleep mode

7. Power up the mount

8. Load StellariumScope (which will also load Stellarium), and connect to the mount in the program

9. Load up EQMOD and polar align using EQMOD and the polarscope:

a) Rotate through RA using the setting circle to position the smaller target circle where Polaris should be (use PolarFinder App) and lock your clutch

 Use the Alt Az bolts to position Polaris in the small target circle

c) Rotate through RA with an unlocked RA clutch and ensure that Polaris sticks exactly to the larger circle

d) Put the top and bottom caps back on the Polar Scope

e) Remove the cap from the guidescope

f) Put the mount in the “Home” position, i.e. mount facing north, weight bar facing the ground, telescope facing Polaris, and lock the RA and Dec clutches

Drift Alignment

1. Choose a meridian star in Stellarium and slew to it

2. Centre the star using APT Liveview

3. Leave the mount tracking for 5 minutes

4. Centre the Meridian Star using the Alt/Az bolts

5. Go to the Horizon Star using Stellarium

6. Centre the star in Live View using APT Liveview

7. Leave the mount tracking for 5 minutes

8. Centre the Horizon Star using the Alt/Az bolts

3-star Alignment

1. Start up APT and PHD2 on laptop

2. Choose a star (in the region to be imaged) to align to in Stellarium and slew to it

3. Use a combination of APT Liveview and the Live View in the camera (through EQMOD?) to centre and sync to the star

4. Use the Bhatinov Mask to set camera focus to infinity (first star only):

a) Switch on the camera, and double-check that it is in 3200 ISO and long exposure mode

 Remove the cap from the scope

c) Hang the Bhatinov mask on the front of the scope

d) Using the Live View x10 of the camera, focus on the star

e) There should be three diffraction spikes

f) The centre spike may not be centred

g) Focus the scope until the three spikes are perfectly aligned, and the central spike is dead centre

h) Remove the Bhatinov Mask

5. Focus the guide scope as well

6. Repeat steps 1-2 twice more (3-star alignment)

Imaging

1. Slew to the target and click Shoot in APT to make sure it is framed correctly, centering the target where required

2. Choose guide star in PHD2 and calibrate

3. Set camera settings:

a) Exposure length - Bulb

 ISO - 800

4. Determine longest available sub length before star trails appear:

a) Take a 90-second sub (or higher?), then zoom in on Live View on the camera

 If there is star trailing, then decrease the sub length by 30-seconds

c) Repeat until there is no star trailing

5. Lights - take as many Lights as required

6. If you want to image another target then do it now, before Flats and Darks

7. Return the mount to the “Home” position using Stellarium, then switch the mount off

8. Flats:

a) Switch the camera in AV mode, 100 ISO

 Set the timer remote to take one shot, shortest exposure available, with a 10-second delay, and 5-second interval

c) Hold a piece of paper in front of the laptop screen, and hold the laptop up to the front of the scope

d) Take one shot

e) Check the histogram of the shot. If the peak is around one third to half, then set the timer to take lots more shots, ideally 50

f) If the peak is too low or too high, then decrease/increase the PC monitor brightness, take another test shot, repeat until the peak is around one third, and then take lots of shots

9. Darks:

a) Remove the dew shield and put the telescope cap on

 Rest the scope on the toolbox do you can start packing up

c) Put the camera back in Manual mode, same ISO as the Lights

d) Set the remote timer to take as many shots as you can cope with (same sub length, ISO and interval as the Lights)

e) Take the Darks and start packing up

Does that look like it makes sense?

I'll also have to start reading some tutorials for EQASCOM (I have the ASCOM platform installed), PHD2, StellariumScope/Stellarium, and APT, all of which I now have installed.

[ianpwilliams]

What jobs do the various programs do? It seems to be something like:

Stellarium (using StellariumScope) - select targets, slew to them, centre stars etc (effectively replacing the SynScan)

EQMOD - helps with polar alignment, although how does it help exactly? I normally use my PolarFinder App to check where Polaris should be and rotate the RA based on that, and then use the Alt-Az bolts to centre Polaris in the small circle. I'm not sure how EQMOD can help with that, given that it can't see through the polarscope

APT - view the camera's Live View through APT on the laptop. And possibly change camera settings such as ISO and sub length? I'm guessing that you wouldn't be able to switch from Manual mode to AV mode though (for taking Flats), seeing as it's a physical wheel on the camera that has to be rotated? Or does it take complete control of the camera?

PHD2 - guide the camera via the laptop using the guide cam

Is that correct?

[ianpwilliams]

I've watched a video about polar aligning in EQASCOM. Does this look about right:

Polar Alignment (EQMOD_ASCOM, PolarFinder App)

1. Remove the top and bottom caps from the front Polar Scope

2. Put the mount in the “Home” position, i.e. mount facing north, weight bar facing the ground, telescope facing Polaris, and lock the RA and Dec clutches

3. Rotate the Dec (and telescope) so that the telescope is side-on to Polaris, facing over your shoulder (so you can see through the polar scope)

4. Connect the EQDIR cable from the mount to the laptop

5. Connect PS2 controller to the laptop

6. Connect mouse to the laptop (or use the laptop mouse button)

7. Bring the laptop out of sleep mode

8. Power up the mount

9. Load StellariumScope (which will also load Stellarium), and connect to the mount in the program

10. Load up EQASCOM and polar align using EQASCOM and the polarscope:

a) Click the spanner icon to expand the main window

 Uncheck “Enable Limits” button in “Mount Limits”

c) Choose “12 o’clock” from the pulldown menu in EQASCOM

d) Use the Alt-Az bolts to centre Polaris in the middle of the Polarscope crosshair, then move Polaris up to the top edge of the circle using the Alt bolt only

e) Use either the buttons in EQASCOM or a gamepad to rotate the RA so that the small circle is centred around Polaris at 12 o'clock

f) Click “Set Polarscope Home” to save it for future sessions

g) Click “Align Polarscope” to have EQASCOM rotate the RA axis to so that the small circle is where Polaris should be

h) Use the Alt Az bolts to position Polaris in the small target circle

i) Check “Enable Limits” button in “Mount Limits”

j) Put the top and bottom caps back on the Polar Scope

k) Remove the cap from the guidescope

l) Put the mount in the “Home” position, i.e. mount facing north, weight bar facing the ground, telescope facing Polaris, and lock the RA and Dec clutches

[D4N]

Stellarium - yeh pretty much.

EQmod - EQmod interfaces directly with the mount bypassing the handset. You can polar align in several ways and not all rely on the position of Polaris. You can star align correcting star positions with the mount adjustments or you can drift align correcting star drift with the mount adjustments, the latter would normally be done in PHD2.

APT - Depends on the camera I guess. I take flats in full manual anyway.

PHD2 - yes, can also be used to drift align the mount.

Astro Tortilla is also handy, this plate solves an image and realigns the scope to where it is supposed to be pointing. Tricky to set up so I would suggest doing it in the day with some old unprocessed light frames.

/Dan

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[ianpwilliams]

Ok, having viewed/read tutorials online, this is what I have now for my Primary Setup, Polar Alignment, 3-star alignment, Guiding, and Imaging (I'm not going to do Drift Alignment, at least not to begin with, because the SGL guided imaging thread suggested that it's not really necessary at my short focal length):

Primary Setup

1. Place the tripod down without the legs fully extended, with the “N” leg facing North

2. Attach the accessory tray to brace the legs

3. Ensure that the tripod is level all three ways using a spirit level, and by adjusting the length of the legs

4. Put the mount on the tripod with the weight bar pointing to the ground

5. Attach the weights then the telescope to the mount

6. While supporting the scope, unlock the RA clutch, rotate the RA to 90 degrees, and then lock the RA clutch

7. Tilt the RA left and right, and feel for imbalance. Adjust the position of the weight until balance is achieved. For imaging, leave the balance with a slight bias East heavy

8. While supporting the scope, unlock the DEC clutch, rotate the DEC so that the scope is roughly parallel to the ground and check for imbalance.  Loosen the dovetail rings and rotate the scope in the dovetail until balance is achieved, then tighten the dovetail rings

9. Return the mount to the “Home” position

10. Adjust the altitude bolts on the mount until you can see Polaris through the Polar Scope

Polar Alignment (EQASCOM)

1. Remove the top and bottom caps from the front Polar Scope

2. Put the mount in the “Home” position, i.e. mount facing north, weight bar facing the ground, telescope facing Polaris, and lock the RA and Dec clutches

3. Rotate the Dec (and telescope) so that the telescope is side-on to Polaris, facing over your shoulder (so you can see through the polar scope)

4. Connect the EQDIR cable from the laptop to the mount

5. Connect the USB cable from the laptop to the guide camera

6. Connect PS2 controller to the laptop

7. Connect mouse to the laptop (or use the laptop mouse button)

8. Bring the laptop out of sleep mode

9. Power up the mount

10. Load StellariumScope (which will also load Stellarium), and connect to the mount in the program

11. Load up EQASCOM and polar align using EQASCOM and the polarscope:

a) Click the spanner icon to expand the main window

 Uncheck “Enable Limits” button in “Mount Limits”

c) Choose “12 o’clock” from the pulldown menu in EQASCOM

d) Use the Alt-Az bolts to centre Polaris in the middle of the Polarscope crosshair, then move Polaris up to the top edge of the circle using the Alt bolt only

e) Use either the buttons in EQASCOM or a gamepad to rotate the RA so that the small circle is centred around Polaris at 12 o'clock

f) Click “Set Polarscope Home” to save it for future sessions

g) Click “Align Polarscope” to have EQASCOM rotate the RA axis to so that the small circle is where Polaris should be

h) Use the Alt Az bolts to position Polaris in the small target circle

i) Check “Enable Limits” button in “Mount Limits”

j) Put the top and bottom caps back on the Polar Scope

k) Remove the cap from the guidescope

l) Put the mount in the “Home” position, i.e. mount facing north, weight bar facing the ground, telescope facing Polaris, and lock the RA and Dec clutches

3-star Alignment (APT and EQASCOM)

1. Start up APT on the laptop:

a) Click “Connect” (top-right) to connect to the camera

 Click “Live View” (top-right) to view through the camera

c) Select ISO 3200 (bottom-right) for centring stars and focussing later

d) Select “RAW” for Quality

e) Select “Camera” for image destination

f) Click “Shoot” to take a shot

2. Choose a star (in the region to be imaged) to align to in Stellarium and slew to it

3. Use a combination of APT Liveview and the Live View in the camera (through EQASCOM) to centre and sync to the star

4. Use the Bhatinov Mask to set camera focus to infinity (first star only):

a) Double-check that camera is in 3200 ISO and long exposure mode in APT

 Remove the cap from the scope

c) Hang the Bhatinov mask on the front of the scope

d) Using the Live View x10 in APT, focus the telescope on the star

e) There should be three diffraction spikes

f) The centre spike may not be centred

g) Focus the scope until the three spikes are perfectly aligned, and the central spike is dead centre

h) Remove the Bhatinov Mask

5. Repeat steps 1-3 twice more (3-star alignment)

6. Slew to the target, click shoot in APT, and ensure that it is framed correctly

Guiding (PHD2)

1. Start up PHD2 on the laptop:

a) Click the “Camera” button to connect to the guide camera and mount (or if you’ve connected before, then hold Shift and click the “Camera” button, which will connect everything automatically) - Ensure that the imaging camera, guide camera, and mount are all correct, and then click the “Connect” buttons

 Choose an exposure duration - as a starting point, try using exposure durations of 1-5 seconds initially (or try auto-exposure?)

c) Click on the “Loop” button, and look at the available stars, adjusting guide scope focus if required. Adjust the exposure duration (and slew the mount if required) in order to find a suitable guide star

d) Click on a non-saturated star that’s not very near an edge for use as a guide star (or press Alt-S to have PHD2 choose one for you)

e) Click on the Guide button to start guiding

Imaging

1. Change camera settings in APT:

a) Exposure length - 3 minutes (or higher?)

 ISO - 800

2. Determine longest available sub length before star trails appear:

a) Take a 3-minute sub (or higher?), then zoom in on Live View in APT

 If there is star trailing, then decrease the sub length by 30-seconds

c) Repeat until there is no star trailing

3. Take as many Lights as required

4. If you want to image another target then do it now, before Flats and Darks

5. Return the mount to the “Home” position using Stellarium, then switch the mount off

6. Flats:

a) Switch the camera in AV mode, 100 ISO

 Set the timer remote to take one shot, shortest exposure available, with a 10-second delay, and 5-second interval

c) Hold a piece of paper in front of the laptop screen, and hold the laptop up to the front of the scope

d) Take one shot

e) Check the histogram of the shot. If the peak is around one third to half, then set the timer to take lots more shots, ideally 50

f) If the peak is too low or too high, then decrease/increase the PC monitor brightness, take another test shot, repeat until the peak is around one third, and then take lots of shots

7. Darks:

a) Remove the dew shield and put the telescope cap on

 Rest the scope on the toolbox do you can start packing up

c) Put the camera back in Manual mode, same ISO as the Lights

d) Set the remote timer to take as many shots as you can cope with (same sub length, ISO and interval as the Lights)

e) Take the Darks and start packing up

How's that looking do you think?

I intend to do a couple of dry runs indoors before I attempt to do anything outside, which will undoubtedly bring up more questions.

[D4N]

For your flats if you are in AV mode you can't set the exposure time, this will be automatic. Not sure why you are changing the ISO for the flats?

I just set my iPad to full brightness and adjust the exposure in manual mode, I know a lot of people do use AV though.

/Dan

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[ianpwilliams]

Yeah I actually knew about not being able to set exposure length in AV mode, not sure why that is in there. As for 100ISO I can't remember why that was, someone suggested it. Either way the flats produced seem to be decent enough. I do have to use the laptop as a light source though, so I'll have to disconnect the various cables etc and use the camera manually for the flats, and possibly the darks too.