TheSkySearchers-Welcome!

So I missed NGC 4473 and and NGC 4477 - I'll do better next time (which will be earlier in galaxy season next year).

It is a little late in the season for me to go after this target as it disappears into the trees about three hours after crossing the meridian, and I don't reach full astronomical dark until after it has already passed to the west side. I thought about going after M51, but I've captured that guy three times in the past 4 years, so decided to go for the Chain Thursday night.

I had some trouble with the APT Bahtinov Aid again where it was reporting that I was in the .11 to .29 pixel range for focus, but it turned out when I zoomed in later that I wasn't even close and stars were showing donut holes in the center. I need to get that working properly, it seems my results are hit or miss, not sure what I'm doing wrong there. I did really well in my March session, but one of my two February nights was shaky. I have gotten much more consistent results out of BYEOS's baht tool over the years and just need to figure this new guy out.

By the time I got pointed at the Chain it was almost 10 PM. I realized I needed to rotate the camera to capture everything, but decided to go on as I had it rather than burn another 20 minutes slewing to a bright star to re-focus, then coming back to the target and re-framing. As it turned out I was in the trees by 12:35 AM on Friday morning. I managed to get 37 180 second subs for a total of 141 minutes of lights. Stacking was done using DSS along with darks, flats, and bias frames. I tried to get by without the darks initially as I didn't have any that are close in temperature to my lights for the night, but DSS picked up the hot pixels as stars and tried to align everything to them. As I was dithering the resulting stack wasn't at all useful, so I added some darks that were about 10 degrees off and got a usable stack out of that. Post processing was done using StarTools.
After the Chain hit the trees, I switched over to M51 until it hit the trees about 90 minutes later. I haven't taken a look at that data yet.

My plan for next month is to work on the Western Veil for an entire night (or two) picking it up low in the East and following it across the meridian until the sky starts to lighten up. Hoping for some clear moonless nights!

Bob

Nice looking image Bob. Good details and lovely stars.

A bit of a bright region just to the right of center which I'm not sure about.

Steve

That's a good collection of galaxies Bob. Some nice coloured stars too.

I don't use the APT Bahtinov aid, I just zoom X5 in live view and tweak the line to the centre of the cross by eye. It does the job.

Regards

Graeme

Nice “Chain” Bob!

I’m glad that you got out to get some imaging time in!

Sorry to hear the “troubles”. I had a bunch of that the last time I was out. Only different ones. You managed to pull through nicely and collect some good data.
You are probably already doing this, but are you using the batinov aid with live view? If so, I’ve found that using a stack count setting of 10-15 tremendously settled down the “jumping”. My seeing is usually terrible, so, until I found the stack count setting, I would shoot for the “best” average of the jumps or doing as Graeme said works pretty well too. Just give it a second or two to settle after an adjustment since it takes a small bit of time (literally seconds) to “stack”the live view images.
Or, shooting single 4-5 second exposures works very well too.

Focus has been a big part of my “focus” recently since adding the ASI focus motor. Steve [mention]STEVE333[/mention] was very helpful in getting my backlash worked out. I’ve only imaged with it once so far, but I had very good success using the APT Autofocus Aid to focus on a star in the target fov (in this case M51). I focused initially on Arcturus with the batinov, then refocused four times using the Autofocus Aid Tool while imaging M51 without moving the scope. Just stopped the imaging plan, selected a good star in the fov and ran the tool. Then went back to imaging. Of course, I zoomed in on particular stars before and after adjusting focus just to be confident with the tool.

Really nice image!

Thanks

Graeme1858 wrote: ↑Sun May 24, 2020 7:35 am That's a good collection of galaxies Bob. Some nice coloured stars too.

I don't use the APT Bahtinov aid, I just zoom X5 in live view and tweak the line to the centre of the cross by eye. It does the job.

Regards

Graeme

Thanks for the tip, Graeme. I have been avoiding live view to control the sensor temperature, but may give it a shot to get this under control.

Juno16 wrote: ↑Sun May 24, 2020 11:01 am Nice “Chain” Bob!

I’m glad that you got out to get some imaging time in!

Sorry to hear the “troubles”. I had a bunch of that the last time I was out. Only different ones. You managed to pull through nicely and collect some good data.
You are probably already doing this, but are you using the batinov aid with live view? If so, I’ve found that using a stack count setting of 10-15 tremendously settled down the “jumping”. My seeing is usually terrible, so, until I found the stack count setting, I would shoot for the “best” average of the jumps or doing as Graeme said works pretty well too. Just give it a second or two to settle after an adjustment since it takes a small bit of time (literally seconds) to “stack”the live view images.
Or, shooting single 4-5 second exposures works very well too.

Focus has been a big part of my “focus” recently since adding the ASI focus motor. Steve @STEVE333 was very helpful in getting my backlash worked out. I’ve only imaged with it once so far, but I had very good success using the APT Autofocus Aid to focus on a star in the target fov (in this case M51). I focused initially on Arcturus with the batinov, then refocused four times using the Autofocus Aid Tool while imaging M51 without moving the scope. Just stopped the imaging plan, selected a good star in the fov and ran the tool. Then went back to imaging. Of course, I zoomed in on particular stars before and after adjusting focus just to be confident with the tool.

Thanks, Jim. Sounds like two votes for the live view and zoom. I haven't been doing that, I have been doing individual images and laying the baht tool over the result. It appears that the ability to zoom is going to be a requirement to get this right. I took a look at the focus images from Thursday night. When zoomed they clearly show the spikes out of alignment, but the tool still shows very close focus. It may be an issue with the tool, not with me

I see the bright area more clearly in the image now that it is posted. I have a couple of things to check out. For one, it appears I had a light leak somewhere, possibly through the camera eyepiece. I use the little cover Canon supplied but it may not be doing the job anymore. I started taking darks before sunset. The scope was fully shaded but the dark that collected before sunset had some really nasty gradients in them. I tried not to use those when stacking but I may have some issue there. Also It was a bit dewy by the of the night when I did my flats and they may not be as effective as usual. I will find out more when I process the M51 frames.

Bob

[quote=bobharmony

Thanks, Jim. Sounds like two votes for the live view and zoom. I haven't been doing that, I have been doing individual images and laying the baht tool over the result. It appears that the ability to zoom is going to be a requirement to get this right. I took a look at the focus images from Thursday night. When zoomed they clearly show the spikes out of alignment, but the tool still shows very close focus. It may be an issue with the tool, not with me

I see the bright area more clearly in the image now that it is posted. I have a couple of things to check out. For one, it appears I had a light leak somewhere, possibly through the camera eyepiece. I use the little cover Canon supplied but it may not be doing the job anymore. I started taking darks before sunset. The scope was fully shaded but the dark that collected before sunset had some really nasty gradients in them. I tried not to use those when stacking but I may have some issue there. Also It was a bit dewy by the of the night when I did my flats and they may not be as effective as usual. I will find out more when I process the M51 frames.

Bob
[/quote]


I get those “leaks” too when I shoot darks when it’s not dark. I drape a black trash bag over the camera also, but not enough to keep heat in.

I shot some darks last night when I was watching tv to get some ‘warm’ darks. Heck, APT recorded 82 degrees F! I could see hot pixels on the APT preview window!

I love the cool months!

Nice work Bob!

I love that area - so many Galaxies to find!. nicely done.

It appears to be the flats that are the cause of my sky glow right of center. I got the same area lit up when I processed the M51 data from the same night, even after I removed the darks from that stack.

I guess I'll have to think about collecting flats earlier in the night so they don't get impacted by dew. For this guy I may drop into Photoshop and do some masking and adjusting to clean it up.

Bob

I went into Photoshop applied a mask that I defined with the Magic Wand tool and darkened the light background area with a Curves adjustment. At first glance I like the result.
Bob

Looks really good Bob!