What did I get?

[blackstar]

I was experimenting with catching the North American Nebula with z8+z105mm (without tracker). I didn't know where the NAN was exactly in the dark sky but saw it from Stellarium was close but higher than Vega in the direction between W and NW. So I just aimed in that direction and saw massive stars in the frame as I focused into infinity. Took two dozen shots and several Darks and Biases. Thinking of using Siril to stack the Lights and process, but unfortunately, all of the Lights except one are useless due to trails (I didn't think 5" is too long for 105mm). So took the only remnant (which is still with a little trail) and tried to get/save something out of it from Gimp... Surprised! The first picture is the original, the second is processed with Curve, and the third is processed by Level. What do you think I have caught?

 

[BF Hammer]

A massive vignette.

Really ought to use a tracker on multi-second exposures at telephoto length. This is most needed at the elliptical plane. I did my comet photos without tracking, and at 70mm anything above 1 second had trails. I also forgot to flip off the VR switch so that added to my problems.

 

[blackstar]

A massive vignette.

...

If it is, what does the center part reveal? lol

Yeah, I do need a tracker... still considering functionality, mobility (size and weight, most are too bulky for my like), and loading capacity. Would like models with automation (like smart trackers) for this aged body. Still, most of them are for telescope/astro-camera systems, not there yet...

 

[BF Hammer]

Maybe consider a less-ambitious target without a tracker. Jupiter and Saturn are actually fairly easy as long as you can keep the planet in the FOV as you work. Orion Nebula also since it is so visible bare-eyed.

I just took a trip down memory lane from 2019 which is shortly before buying my go-to telescope mount. Photos are truly bad but they had me so excited at the time that I actually could take photos of those objects with only a camera and 600mm lens.

Keep trying!

 

[blackstar]

Thanks for sharing, BF. I remember you had shots with a tracker on the same targets. I would like to see the images with shooting and technical data.

Will try Orion with 105mm for 3-4". 600mm won't do longer than 8/10" without a tracker. I regret selling z180-600mm for acquiring z600mm (for the weight issue).

In terms of camera settings, AP and other types of photography (e.g., Wildlife) have vast differences. Do you use shooting banks to remedy the issue? Most people I hear claim the bank setting is clumsy and confusing to use.

Do you have tips for finding Orion in the dark sky? Appreciate.

 

[BF Hammer]

Orion nebula is the most visible nebula in sky. You would likely mistake it for a star in the "dagger" below Orion's belt. It is easy to over-expose it. In winter Orion is the dominant constellation and most people learn to recognize it like the big dipper. There are certain other constellations I pick out instantly like Cassiopeia and Hercules.

Have you tried the Stellarium phone app? Pretty decent for a quick check where an object should be in the field. It won't do the trick other apps do though where it displays on screen what it is aimed at, but it's free.

Another target that would work good is Pleiades (star cluster). It is quite bright in the sky and is rising ahead of Orion this time of year earlier in the night. It does have some nebulosity in the cluster, but it is hard to show it without a large exposure stack.

Really for camera settings, just go to manual mode. Some things like aperture will always be wide-open unless you are shooting Jupiter (typically I have done that at f/8). Go right up to ISO 1600 and it may be necessary to go to ISO 6400 (no auto ISO for this). Then shutter is going to be limited by the fact you are not using a tracker yet. Longer focal length, faster shutter. Take test photos and adjust.

 

[BF Hammer]

For reference kind of as you ask for. However the software I was using back then tended to strip off the EXIF data.

Orion with a 90mm Tamron lens. Belt at the top gives the reference for the Orion Nebula lower down. Bottom right is also another star of the visible constellation.

Found this photo I took of my astro-rig in 2020. Today I am upgraded to a Z5, better tripod, and I normally will shoot tethered to a notebook PC for easier camera control. Actually once the mount is properly set up and polar-aligned it all becomes a sit-down operation as I bring a TV table and folding chair. DigiKamControl even lets me fine-adjust focus remotely by the AF motor.

 

[BF Hammer]

Back on original question: I believe Cygnus is top edge-center and NAN is just off frame up. But it is really hard to pick that out. Had to go back and forth between Stellarium and the photos many times looking for the patterns in photo #1.

And I just discovered you can point-view Stellarium mobile to assist in live identification. Nice!

 

[blackstar]

Wow!!! As you did (going back and forth between SL and the image), I am surprised to see it IS (most likely) the Cygnus/Crescent Nebula which is below the NAN (just out of the frame)!

Now I wonder if I have 20 Lights, can they be stacked and processed (in Siril) to make the result like the above on the nebula part except for many stars blocking the details as the single shot showed?

 

[blackstar]

...

And I just discovered you can point-view Stellarium mobile to assist in live identification. Nice!

How? I was excited to hear this. But after hours of research, nowhere, nothing was found to enable my new iPhone 15 Plus to do this. Not even able to open the camera and SLM (Stellarium Mobile) at the same time, if it's required to point-view in live ID. No guide for this was found either... Help needed.

 

[BF Hammer]

How? I was excited to hear this. But after hours of research, nowhere, nothing was found to enable my new iPhone 15 Plus to do this. Not even able to open the camera and SLM (Stellarium Mobile) at the same time, if it's required to point-view in live ID. No guide for this was found either... Help needed.

Look at the bottom of the screen of Stellarium mobile. On my Android phone I find a small compass. I believe I touched it and lingered on that touch a bit and it started moving the view as I moved the phone. Touch the sky and scroll, the tracking stops.

 

[blackstar]

Thanks much, BF. On my iPhone screen, the compass is kind of hidden in a tree on the right side of the foreground. Finally, sort it out and get the point-view scene.

 

[blackstar]

The object in the image I shot is more like a Globular Cluster in or behind the Cygnus constellation. Here are some Globular Cluster photos:

NGC 104

M80

 

[blackstar]

Ok, I tried again. Still failed (lost focus on stars) with three dozen lights except one. This one looks pretty much the same as the last try except there is strong evidence that makes certain what I had caught is actually the Cygnus constellation (with very little detail though). Compared to Stellarium's image, there is the bright Sadr in front of the center of Cygnus. It does show in the image I caught. I expect it's very possible to image night stars/celestial bodies with great details when equipped with a tracker (in my next purchase list) for multiple long exposures. Here are the images:

Original

Processed

Cygnus from SL

 

[BF Hammer]

The lost focus may really be fogging in the lens. It's very common and addressed with an inexpensive USB powered lens heater wrap.

 

[blackstar]

Thanks for the heads-up on the fogging issue, BF. You remind me to think back on the situation. It did get cold and damp when I shot the images. I have not considered this issue, only the settings and operating were on my review list. Just before this trial, I set up shooting banks (both menu and custom) on my z8 for future operations (wildlife, Astro). It's pretty complicated and confusing at first. But I thought I had managed to tackle it. After the trial and all the lost focus, I wonder if I did something wrong in the bank settings and operated the shooting without knowing it. I had "focus" set for both the back button and the shutter button (MF). For my first shot, I aimed at a bright star (Sadr?), magnified it, and used the focus ring to pinpoint it, but couldn't get the white dot (confirm focus) steady only making both > and < constantly appear at the same time. Then I pressed BB (make sure > and < still stand) and took a shot (I had 2" delay shooting). After that, I just made sure both > and < stayed put and pressed SB to take the next shot... What happened was that except for the first shot, all the following shots lost focus (stars bloated). I wonder if I need to change back to focusing on BB only (as I do for wildlife) since after the first shot I don't have to focus again, right? Or something else I did wrong? Any thoughts?

 

[BF Hammer]

Switch off AF as soon as you have it where you want. Infinity focus is good for the entire night sky.

My focus process is to pick a bright star, zoom the display in as far as it goes and manually adjust until the star is as tight of a point as can be. That is infinity focus. Then aim on target, hands off the focus ring.

Quick note about a dew heater: they run about $25-$35 on Amazon. I use a 20V power tool battery with a power tap attachment. The tap has 2 USB ports and a 12V coaxial jack that I use to power my star tracker. A simple power-bank phone charger can power the dew heater easily if you don't need the 12V. Stuff to consider.

 

[blackstar]

"Switch off AF" ??? -- I am on MF when shooting Astro.

"My focus process is to pick a bright star, zoom the display in as far as it goes and manually adjust until the star is as tight of a point as can be. That is infinity focus. Then aim on target, hands off the focus ring." -- and then how do you take shots? Do you use BBF or SBF? You have to press either BB (Back Button) or SB (Shutter Button) to take shots, right?

 

[BF Hammer]

Now I'm confused. What function does BBF or SBF have when you manually set focus with your eyes? Wait, do you have that shutter release on focus feature turned on?

For the record I plug in a remote shutter release. I have 2, a plain remote and a programmable intervalometer kind. Or I tether to my laptop and control it all that way.

 

[blackstar]

After you manually focus with your eyes (adjust the focus ring), if you set BBF-only, pressing BB will fix the focusing point. If you set SBF & BBF, (I wonder) how you can fix the focusing point because every time you press SB, it will refresh the focusing (make a new focusing). I had default (SBF & BBF) on. Now I have changed it to BBF-only (just like in Wildlife).

I don't want to bother using a remote shutter release (programmable or not). For now, I will use the built-in interval-timer shooting (z8) to make multiple exposures -- before getting a smart star tracker.