Various questions

[lazjen (Chris)]

A poor subject title, sorry, but after last night's session with the gear in the backyard I've got a few questions to ask. Since I'm a beginner I'm posting here, but if the topic belongs elsewhere, feel free to shift this thread. If the wall of text is too much, jump to the end for the "TL;DR, questions listed" bit.

Background: My current main goal is to take some good DSO images using a DSLR from my backyard. My "sub-goals" towards this include learning to do good polar alignment; focusing; understanding and recognizing errors and limitations as they appear on the images.

1. Polar Alignment. This was interesting as I can't see SCP from my setup location. It's blocked by the house. I used the G11's PA assist routine (http://gemini-2.com/hc-English/E026.php) and while that was good, I found that when it slew to the star it was so far off that I could barely see it in the finder scope (sometimes it wasn't even in the field of view). To be thorough: I'm fairly certain I've set lat/long correctly. Time set is probably within 1 minute - does this need to be more accurate?

I did note that I was "generous" with my mount level when I set it up. I did note a significant improvement in the PA when I adjusted things further to a more rigorous level.

From this point I started taking longer images (about 30 sec to 1 minute) to check the alignment and attempt to correct errors found. I had issues with focus (I'll detail below), but by iteration the gross trailing in the images was soon (relatively) gone.

2. Focus. I had a lot of issues with this. I did the G11 PA assist with the eye piece in, so focus wasn't an issue. I then switched in the camera to check the results of the PA as I don't believe I have any other way to do so via the eye piece. I found it difficult to focus with the live view either on the back of the camera or on the computer screen. I think this was a combination of issues - it's quite a precise focus required and small movements either way could throw it out. The small screen on the back of the camera, even at 5x or 10x wasn't easy to see the differences. It was slightly easier on the computer screen - but a current limitation is the computer is inside, not conveniently near the scope. Then there was the to-ing and fro-ing between screen and focus adjuster. In the end, the best result I got was pointing to the moon and focusing on that before heading elsewhere.

I did some research and note the use of Bahtinov Mask to help focus. Does a Bahtinov Mask work well with the live view mode of the DSLR?

Although I may get a laptop in the near future to be able to bring closer to the scope, I think my manual fiddling with the focuser is error prone. What alternatives to manual focusing can I look into? Any recommendations for my setup (see sig)?

With the DSLR, I noticed that the focus got softer the more I zoomed in on the captured image, so while it might look ok at certain resolution/zoom levels, looking too "closely" is not good. I've read that this is something to expect with DSLRs, so I'm not overly concerned. For my Canon EOS 6D, how can I determine the quality of my focus for an image and/or how much zoom can I expect to be able to do and still have reasonable focus?

3. Errors and Limitations. After a couple hours of the above last night, I got to the point where I thought I could grab some images to process. I wasn't concerned at this point to be accurately picking a target - I just wanted to grab some data and see what errors popped up. I went to ISO 800 and 1 min exposures, and I was pointing somewhere around Eta Carina (ok, I was greedy and wanted some pretty colours ). Because the images were downloading to my computer, I could see what was happening after each shot. And the results were interesting and not consistent. I took 33 images in total over a few sets. Ignoring some soft focus issues, about 5 to 8 (I think) were acceptable to DSS to use. I think I know why most images were rubbish (e.g. needed to improve PA further for example) and I hope to post example problems in follow up posts to get specific feedback. Ignoring my skill level in the equation (as hopefully that will change ), how can I determine the maximum exposure length I can effectively do given the conditions to minimise problems? Given 5 or so images "worked" while others didn't, there's some variables I have not accounted for at this time.

Finally, how far can I possibly go for exposures without using guiding?

Thanks for any advice/assistance!

TL;DR, questions listed:

1. Time set is probably within 1 minute - does this need to be more accurate for PA and/or pointing to a location?

2. Does a Bahtinov Mask work well with the live view mode of the DSLR?

3. What alternatives to manual focusing can I look into? Any recommendations for my setup (see sig)?

4. For my Canon EOS 6D, how can I determine the quality of my focus for an image and/or how much zoom can I expect to be able to do and still have reasonable focus?

5. Ignoring my skill level in the equation (as hopefully that will change ), how can I determine the maximum exposure length I can effectively do given the conditions to minimise problems?

6. Finally, how far can I possibly go for exposures without using guiding?

[lazjen (Chris)]

Right, here's some images, straight jpg conversions of the raw files. Ignore the vignetting - I'm working on fixing that. Files are large in size, be warned.

ISO 800, 1 min exposures.

Ok Image

I suspect some of the following errors are related to each other:

Error 1
Error 2
Error 3
Error 4
Error 5

I think that's a fairly good representation of the error types I got. If not, when I sort these out the rest should become clearer.

[lazjen (Chris)]

Upon closer examination of the images DSS thought ok enough to use (and a sample linked previously), I can see they've got problems, just harder to see at first. Zooming in shows little 'u' or 'crescent moon' shapes on the stars.

[multiweb (Marc)]

Originally Posted by lazjen

1. Polar Alignment. This was interesting as I can't see SCP from my setup location. It's blocked by the house. I used the G11's PA assist routine (http://gemini-2.com/hc-English/E026.php) and while that was good, I found that when it slew to the star it was so far off that I could barely see it in the finder scope (sometimes it wasn't even in the field of view). To be thorough: I'm fairly certain I've set lat/long correctly. Time set is probably within 1 minute - does this need to be more accurate?

The first goto you do is always likely to be off. So the trick is to mechanically move your mount azimuth and elevation to get the star back in the finder where it should be then synchronise or reset the alignment to your target. From there on do the alignment routine to close in the SCP. Your mount needs to be as level as possible or any change in azimuth will change your elevation as well and vice-versa.

Originally Posted by lazjen

2. Focus. I did some research and note the use of Bahtinov Mask to help focus. Does a Bahtinov Mask work well with the live view mode of the DSLR?

Yes it will . I regularly use bathinov masks for my lenses from 200mm down to 50mm. Most DSLR will also zoom when you do a focus on a star so it's just a matter to focus in and out. Practice makes perfect.

Originally Posted by lazjen

how can I determine the quality of my focus for an image and/or how much zoom can I expect to be able to do and still have reasonable focus?

Slew to a very bright star and do a 3-5s exposure with a bathinov mask.

Originally Posted by lazjen

3. Errors and Limitations. how can I determine the maximum exposure length I can effectively do given the conditions to minimise problems? Given 5 or so images "worked" while others didn't, there's some variables I have not accounted for at this time.

This will be trial and error unfortunately. Star with 2min then 3, 5min max. ISO800 is ok to start with.

Originally Posted by lazjen

Finally, how far can I possibly go for exposures without using guiding?

You need to get into auto-guiding asap.

[multiweb (Marc)]

Originally Posted by lazjen

Right, here's some images, straight jpg conversions of the raw files. Ignore the vignetting - I'm working on fixing that. Files are large in size, be warned.

ISO 800, 1 min exposures.

Ok Image

I suspect some of the following errors are related to each other:

Error 1
Error 2
Error 3
Error 4
Error 5

I think that's a fairly good representation of the error types I got. If not, when I sort these out the rest should become clearer.

These are all tracking errors. You need to get into auto-guiding.

[lazjen (Chris)]

Marc,

Thanks for your replies.

Originally Posted by multiweb

The first goto you do is always likely to be off. So the trick is to mechanically move your mount azimuth and elevation to get the star back in the finder where it should be then synchronise or reset the alignment to your target. From there on do the alignment routine to close in the SCP. Your mount needs to be as level as possible or any change in azimuth will change your elevation as well and vice-versa.

Right. And tonight's main focus will be to do this better. I think I would have saved myself a lot of wasted time if I had leveled the mount better in the first place. I've marked my position on the ground from last night as well, so I should be begin the process closer to correct.

Originally Posted by multiweb

Yes it will . I regularly use bathinov masks for my lenses from 200mm down to 50mm. Most DSLR will also zoom when you do a focus on a star so it's just a matter to focus in and out. Practice makes perfect.

I'll sort out getting or making one of these soon then.

Originally Posted by multiweb

You need to get into auto-guiding asap.

Ok. It's a whole area I haven't researched much yet. I didn't expect to have to do so until perhaps a bit later on when I consider moving to using a CCD camera. Time to start googling.

[wasyoungonce (Brendan)]

Originally Posted by lazjen

2. Focus. I had a lot of issues with this. I did the G11 PA assist with the eye piece in, so focus wasn't an issue. I then switched in the camera to check the results of the PA as I don't believe I have any other way to do so via the eye piece. I found it difficult to focus with the live view either on the back of the camera or on the computer screen. I think this was a combination of issues - it's quite a precise focus required and small movements either way could throw it out. The small screen on the back of the camera, even at 5x or 10x wasn't easy to see the differences. It was slightly easier on the computer screen - but a current limitation is the computer is inside, not conveniently near the scope. Then there was the to-ing and fro-ing between screen and focus adjuster. In the end, the best result I got was pointing to the moon and focusing on that before heading elsewhere.

I did some research and note the use of Bahtinov Mask to help focus. Does a Bahtinov Mask work well with the live view mode of the DSLR?

Although I may get a laptop in the near future to be able to bring closer to the scope, I think my manual fiddling with the focuser is error prone. What alternatives to manual focusing can I look into? Any recommendations for my setup (see sig)?

With the DSLR, I noticed that the focus got softer the more I zoomed in on the captured image, so while it might look ok at certain resolution/zoom levels, looking too "closely" is not good. I've read that this is something to expect with DSLRs, so I'm not overly concerned. For my Canon EOS 6D, how can I determine the quality of my focus for an image and/or how much zoom can I expect to be able to do and still have reasonable focus?

Ok, perfect focus is best achieved using a computer connected to the DSLR camera and running a camera control software package like BYEOS or APT. Also you may need to re-focus depending upon temperature changes over the imaging period.

Laptops give much bigger screens can be zoomed in much larger with much higher resolution than the rear camera LCD screen.

Also, these DSLR camera control programs have focus routines built into them and control of much more....focuser's, telescope mounts thru ASCOM etc etc.

Spend a few $ on a program and toss the EOS canon utility....you will be glad you did after first use! APT even has a freeware version that has most function enabled so give it a go.

[LAW (Murphy)]

I've got a canon DSLR setup and I've been using Backyard EOS, there's a free trial but I bought the full version because it's so useful. The program has screens to help with drift alignment, focussing, and also separate screens for DSO and planetary photography.

Just with good polar alignment I've managed 2 minute exposures on an old EQ6 but I have to throw out a lot die to tracking errors. Maybe 1 in 4 is good, which is why I'm slowly sorting out an Autoguider.

[lazjen (Chris)]

Originally Posted by wasyoungonce

Ok, perfect focus is best achieved using a computer connected to the DSLR camera and running a camera control software package like BYEOS or APT. Also you may need to re-focus depending upon temperature changes over the imaging period.

Laptops give much bigger screens can be zoomed in much larger with much higher resolution than the rear camera LCD screen.

Also, these DSLR camera control programs have focus routines built into them and control of much more....focuser's, telescope mounts thru ASCOM etc etc.

Spend a few $ on a program and toss the EOS canon utility....you will be glad you did after first use! APT even has a freeware version that has most function enabled so give it a go.

Ah ok, I'm not adverse to spending the money where required and if something like one of these programs will help a lot then I'll grab one. As I mentioned previously, I hope to go to CCD camera one day so I was using DSLR as a stepping stone and not investing heavily in it for software. Still, I prefer to avoid needless pain, so I'll look into these programs.

[lazjen (Chris)]

Originally Posted by LAW

I've got a canon DSLR setup and I've been using Backyard EOS, there's a free trial but I bought the full version because it's so useful. The program has screens to help with drift alignment, focussing, and also separate screens for DSO and planetary photography.

Just with good polar alignment I've managed 2 minute exposures on an old EQ6 but I have to throw out a lot die to tracking errors. Maybe 1 in 4 is good, which is why I'm slowly sorting out an Autoguider.

Have you narrowed your options for an autoguider at all?

[lazjen (Chris)]

After some reading and searching, looks like APT is the way to go. It seems they're making progress with the WiFi mode to the 6D, and if I go CCD in the future, I won't have to relearn a package. I'll download it tonight and hopefully get to try it out.

[Jon (Jonathan)]

Hi Chris,

I've got a very similar setup to yours - G11, with a Canon 60Da and a SCT10" (mines 2540mm focal length f/10, you are at 2000mm f/8). I started imaging about six months ago so I guess I'm a bit further up the learning curve. So some thoughts:

1) Polar alignment - I never found the polar alignment helper much help in the Gemini system. Do a good drift alignment and leave the tripod exactly where it is if you can. I keep mine on a balcony under a tarp. Obviously, I take the mount itself off the tripod!

One of the side benefits of getting set up for autoguiding is that you can use PhD to do a quick polar align. It's easy as pie. See here: http://njstargazer.org/PolarAlignment.asp at the bottom of the page.

Try to set the time as accurately as you can, but you've got plenty of leeway. If you have a field of view of 5 degrees in your finder scope, that equates to 25 mins of sidereal time; in other words, if everything else is bang lined up, the time you enter can be more than 12 mins off and the object should still be in your finder.

BTW, a word on finders: if I'm honest I have more than once been caught out cursing the "unpredictable GOTO alignment" or whatever, before I've realised that the finder isn't lined up with the main scope. It's easily bumped out of place, especially if you are packing the scope up every night. The very FIRST thing you should check, once you've got the first alignment star in the centre of an eyepiece, is that the star is also in the dead centre of your finder, and if not, adjust it. I have to adjust 4 night out of 5.

Finally, as you mention, once you attach the camera, the star that was nicely centred in your eyepiece/diagonal view is way off or nowhere to be seen in the camera live view. Move the scope back so the star in in the centre of the camera view and his Align->Synchronize on the Gemini handset. Or build the model using the camera from the start.

2) Focus

I'm a bit unsure what you mean by "zooming in" on the target. BackyardEOS, which I use and would heartily recommend, will allow you to select and view in close up any stars on your image, to help with focus. But I think you are doing the right thing by focusing on the moon or a bright star first, then going to your target.

I have a motorised focuser that is controlled via USB. It's not cheap ($300 for my focuser plus USB controller) but it is a boon. Allows very precise focus control without all the jumping about you get when you touch the focus knob. Plus, it means I can sit inside and control the scope and camera from the PC! The G11 is a breeze to control with the Ethernet cable.

3) Errors and limitations

Get into autoguiding! As all the others have said. It's not that expensive, and not that complex. Something like this: http://www.bintel.com.au/Astrophotog...oductview.aspx is all you need. I have the larger version http://www.bintel.com.au/Astrophotog...oductview.aspx as the extra precision helps with the long focal lengths. You and I jumped in the deep end with our setups - starting off imaging with a $400 5" f/4 reflector or somesuch atop the G11 would be a *whole* lot easier. You could probably get 1-2 minute unguided subs with such a setup and an f/4 scope is going to collect a whole lot more light an that time than your big slow f/8. However good my polar alignment, I've not been able to comsistently get a usable unguided sub longer than 30" with a 10" SCT on the G11.

For your setup, there's really no choice but to bite the autoguider bullet.

The good news is, it's not that hard, at least to get going. With something like the Orion starshoot autoguider camera in the links above, you just fit the camera into the finder scope, plug a cable from the camera to the Gemini autoguider socket, plug a USB cable from the camera to your laptop, fire up PHD ("Push Here Dummy") free autoguider software, and four mouse clicks later you're off.

I'd also recommend you get a focal reducer when you can afford it. (see this thread: http://www.iceinspace.com.au/forum/s...d.php?t=103278 ). Not only do they create a larger field (without one you won't fit much of Eta Carina onto the image at 2000mm f/8!) they also effectively make the focal ration faster: you're getting more photons per pixel, so your subs can be shorter. So the larger field and smaller objects mean you can take loner subs without tracking/guiding errors showing up; but you need less time to get the same level of brightness. So you're getting a bonus both ways.

So don't worry about zoom. If anything, you want to go in the opposite direction - make the image smaller. You've got 5472 x 3648 pixels to play with - do the "zooming" in Photoshop afterwards by just cropping the bit of the image you want.

I hope this is all of some use. Happy to follow up if I've not been clear.

Cheers

Jonathan

[lazjen (Chris)]

Originally Posted by Jon

I've got a very similar setup to yours - G11, with a Canon 60Da and a SCT10" (mines 2540mm focal length f/10, you are at 2000mm f/8). I started imaging about six months ago so I guess I'm a bit further up the learning curve. So some thoughts:

Always good to hear from more people, especially those with similar situations.

Originally Posted by Jon

1) Polar alignment - I never found the polar alignment helper much help in the Gemini system. Do a good drift alignment and leave the tripod exactly where it is if you can. I keep mine on a balcony under a tarp. Obviously, I take the mount itself off the tripod!

I have no such luck. Although I have a reasonable sized backyard, I'm really constrained in my location due to street lights, roads, etc to a very small suitable area. And it's not a place I can leave setup permanently. Last night I got to setup again, and I "nailed" PA to a similar level very quickly. I've just setup again tonight and have already done some PA to probably close to the same level. I'm waiting for the camera battery to charge (because I forgot to recharge it earlier *sigh*) to check further.

Originally Posted by Jon

One of the side benefits of getting set up for autoguiding is that you can use PhD to do a quick polar align. It's easy as pie. See here: http://njstargazer.org/PolarAlignment.asp at the bottom of the page.

I'll keep this in mind when I get to that point. I know I'll be referring back to this thread as I change/add things.

Originally Posted by Jon

Try to set the time as accurately as you can, but you've got plenty of leeway. If you have a field of view of 5 degrees in your finder scope, that equates to 25 mins of sidereal time; in other words, if everything else is bang lined up, the time you enter can be more than 12 mins off and the object should still be in your finder.

Checked the time tonight - it's certainly within a minute now, maybe 40sec.

Originally Posted by Jon

BTW, a word on finders: if I'm honest I have more than once been caught out cursing the "unpredictable GOTO alignment" or whatever, before I've realised that the finder isn't lined up with the main scope. It's easily bumped out of place, especially if you are packing the scope up every night. The very FIRST thing you should check, once you've got the first alignment star in the centre of an eyepiece, is that the star is also in the dead centre of your finder, and if not, adjust it. I have to adjust 4 night out of 5.

Oh yes. Much cursing the first night I setup when I forgot to line up the finder scope with the main scope. I do a rough alignment just after I balance the scope by pointing off to some distance rooftops. Then, like you've mentioned, fix that up when I align the star.

Originally Posted by Jon

Finally, as you mention, once you attach the camera, the star that was nicely centred in your eyepiece/diagonal view is way off or nowhere to be seen in the camera live view. Move the scope back so the star in in the centre of the camera view and his Align->Synchronize on the Gemini handset. Or build the model using the camera from the start.

I've got better with this part now and do a couple of alignments with the handset to help me out. Useful for helping with focus too.

Originally Posted by Jon

2) Focus

I'm a bit unsure what you mean by "zooming in" on the target. BackyardEOS, which I use and would heartily recommend, will allow you to select and view in close up any stars on your image, to help with focus. But I think you are doing the right thing by focusing on the moon or a bright star first, then going to your target.

Yes, it was just a but difficult to recognize the focus point vs what you see when there's a huge moon surface to see. I think I'm starting to get this a bit better, but the problems remain.

Originally Posted by Jon

I have a motorised focuser that is controlled via USB. It's not cheap ($300 for my focuser plus USB controller) but it is a boon. Allows very precise focus control without all the jumping about you get when you touch the focus knob. Plus, it means I can sit inside and control the scope and camera from the PC! The G11 is a breeze to control with the Ethernet cable.

Ok, this sounds awesome. Is the USB controller connected to the Gemini unit?

And yeah, loving ethernet control of the G11. Played with the web page, plus I've messed around with Stellarium Scope/Stellarium.

Originally Posted by Jon

3) Errors and limitations

Get into autoguiding! As all the others have said. It's not that expensive, and not that complex. Something like this: http://www.bintel.com.au/Astrophotog...oductview.aspx is all you need. I have the larger version http://www.bintel.com.au/Astrophotog...oductview.aspx as the extra precision helps with the long focal lengths. You and I jumped in the deep end with our setups - starting off imaging with a $400 5" f/4 reflector or somesuch atop the G11 would be a *whole* lot easier. You could probably get 1-2 minute unguided subs with such a setup and an f/4 scope is going to collect a whole lot more light an that time than your big slow f/8. However good my polar alignment, I've not been able to comsistently get a usable unguided sub longer than 30" with a 10" SCT on the G11.

For your setup, there's really no choice but to bite the autoguider bullet.

I am convinced, do not fear. I will be looking into this in greater detail very soon!

Originally Posted by Jon

The good news is, it's not that hard, at least to get going. With something like the Orion starshoot autoguider camera in the links above, you just fit the camera into the finder scope, plug a cable from the camera to the Gemini autoguider socket, plug a USB cable from the camera to your laptop, fire up PHD ("Push Here Dummy") free autoguider software, and four mouse clicks later you're off.

As I was reading today I noted that APT can work with PHD, so that's cool too.

Originally Posted by Jon

I'd also recommend you get a focal reducer when you can afford it. (see this thread: http://www.iceinspace.com.au/forum/s...d.php?t=103278 ). Not only do they create a larger field (without one you won't fit much of Eta Carina onto the image at 2000mm f/8!) they also effectively make the focal ration faster: you're getting more photons per pixel, so your subs can be shorter. So the larger field and smaller objects mean you can take loner subs without tracking/guiding errors showing up; but you need less time to get the same level of brightness. So you're getting a bonus both ways.

I have a focal reducer already - a 0.5 2" GSO - but I can't get it to focus with the camera. I think it's too far away from the sensor. I had troubles focusing with the eyepiece as well, until I put the eyepiece right up to the reducer.

Originally Posted by Jon

So don't worry about zoom. If anything, you want to go in the opposite direction - make the image smaller. You've got 5472 x 3648 pixels to play with - do the "zooming" in Photoshop afterwards by just cropping the bit of the image you want.

Yes, I'll not worry about it for now until I see the effects of all the other changes I need to make.

Thanks again for the info.

[lazjen (Chris)]

I think I spoke too soon regarding APT and 6D via WiFi. I may have had the wrong idea about it as the docs seem to suggest USB connection only to the DSLR. I certainly can't seem to get the 2 talking at this time.

[LAW (Murphy)]

Originally Posted by lazjen

Have you narrowed your options for an autoguider at all?

Yeah, I picked an Orion StarShoot Autoguider up in the classifieds and I've modified a Celestron "firstscope" to use it as a guide scope. I just bought a $20 tripod with a "quick release" plate, dismantled it and fixed the head to the tube rings on my 8" and fixed the plate to the 76mm dob so it can be installed and removed without needing adjustment.

I started off with a Tasco 60mm (the infamous "525") which I also picked up for $20 but I found it cumbersome with the 700mm focal length at f/11. The little 76mm ~F/4 newt tube is much more compact, yields more stars and I was so impressed with it's perfomance I actually bought a second one to take hiking!

I only picked the Orion SSAG because it came up at the right time at the right price. Given my time again I'd probably go for the QHY5, which is basically the same camera but with less firmware restrictions. Simply put, the Orion is a dedicated Autoguider, the QHY5 can be used as a capture camera too. Given that I'm usually imaging with my 450D or 550D this isn't a huge restriction, but having options is rarely a bad thing.

[lazjen (Chris)]

Well, it looks like the clouds are rolling back in for a bit, so I'll have to time to sort out some of these issues I think.

I'm sure the wife's going to be impressed that I'll be getting another scope already for this auto-guiding stuff.

A rough summary/list in no particular order:

1. Get Bahtinov Mask.
2. Sort out auto-guider gear.
3. Learn/setup APT. (Got an old netbook I'll setup to USB connect DSLR camera and run APT on for now to get started).
4. Motorised focuser.
5. Sort out focal reducer.

[Jon (Jonathan)]

I'd prioritise 2, 3, 5 in that order. I don't know APT but if it's like Backyard EOS it will give you good feedback about focus. I suspect you are concerned about focus in your subs when in truth it's the guiding that's causing distorted stars. See how you go with the focusing with APT before throwing in the mask or the motorised focuser.

Just my 2c

[lazjen (Chris)]

I think I agree with that priority list - because I have no real way of dealing with the errors that guiding and APT will solve, yet I have managed to get focus, even if it was fiddly work.

[Jon (Jonathan)]

Fiddly is right! I thought I could speed things up by slewing to a bright star, focusing on that with live view, then slewing back to my target and beginning to capture.

Sadly, I've realised that's not enough. So I do that, and once I'm back on my target I take a series of 3 or second, ISO6400 "snapshots" (Backyard EOS allows you to take a quick and dirty jpeg-only snap for this purpose). Between each one I adjust the focus a *tiny* bit trying to get the FWHM value as low as possible.

My experience with astroimaging so far is to remind me that, sometimes, there are no shortcuts :-)

[wasyoungonce (Brendan)]

Should be able to do live view FWHM focusing adjustments with BYEOS and APT.

Although to tell the truth I also do FWHM focusing then take a series shorter subs and adjust re-focus to get it right.