Stargazing Level of details in prime focus vs eyepiece images

[Devin-M]

I present to you…

“…the goldman array…”

 

[PhysicoRaj]

I present to you…

View attachment 290358
“…the goldman array…”

View attachment 290359

Waiting for the first light from this! Are all 3 stock?

The Star Adventurer 2i (currently $425) actually allows for 2 cameras if you add a separately sold ball head.

That's great. Though I understood there could be some issues.

I see a lot of people compositing images over multiple nights. Have you tried it? Will imaging 3 narrowbands over 3 different nights work?

 

[Devin-M]

Waiting for the first light from this!

It’s too cloudy the next 2 days and after that the moon will be up for the following 2 weeks so it will be that long before I test. I’ve found it isn’t worth trying to shoot when the moon is up. If you’re in a bortle 2 & the moon is up you’re basically in a bortle 7 at that point.

I see a lot of people compositing images over multiple nights. Have you tried it? Will imaging 3 narrowbands over 3 different nights work?

Yes you can composite from a single camera over multiple nights, I just won’t have patience for that.

 

[Devin-M]

Are all 3 stock?

They are all stock Sky Watcher Star Adventurer 2i Pro Pack mounts but I have macro focusing rails in between each camera and mount so I can balance each camera on the declination axis which is important because otherwise it will become out of balance on the motorized right ascension axis when you swivel to the target from the initially balanced position.

https://optcorp.com/products/sky-wa...GD81VmjiJTU9j1-8wL9nUM70nGhUxT5BoClI0QAvD_BwE

 

[Devin-M]

It’s too cloudy the next 2 days and after that the moon will be up for the following 2 weeks so it will be that long before I test.

On second thought, maybe I’ll have a go tomorrow night. Should be clear and the moon will be down after 9pm onwards.

I took these a couple of nights ago with some handheld 10 second exposures on an iPhone…

 

[Devin-M]

I think tonight went well. I got RGB as well as narrowband Hydrogen, Oxygen and Sulfur data of an emission nebula at 600mm f/9 with 3 cameras running concurrently in a single session. I was on site at about 7:45pm had all 3 narrowband cameras up and running by around 11:30p and let them run until 3am, so that’s over 9 hours of narrowband data in just over 3 hours. I set up one camera with no narrowband filter first to capture rgb, and once this was up and running I got the 2 other cameras capturing narrowband. Once those two were up and running I reconfigured the RGB camera for Hydrogen Alpha and as I mentioned from 11:30p til 3am all 3 cameras were capturing narrowband. I left the cameras running dark frames on the way home and will continue to let the cameras capture more dark frames while I sleep. The settings I chose were pretty extreme on the narrowband… 10 minutes per exposure at 6400iso for the hydrogen and oxygen filters and a full 20 minutes of open shutter per exposure on the sulphur filter. Haven’t had a chance to look at the data but I do know they were in pretty decent focus as I used a bahtinov mask to focus every camera, and again after switching from RGB to Ha. The most troublesome thing that happened was I had very slow internet on my phone for plate solving to confirm aim. Also one of my USB batteries powering the mounts kept shutting off so I ended up running 2 mounts off a single USB battery pack (fortunately it had 2 output ports). Also next time I’ll remember to switch camera batteries when switching from RGB to Ha as I think the Ha session may have ended a little early from the camera battery running out of juice at some point. All in all I deem the mission a success (having not yet seen the actual data). Will begin processing data tomorrow…

 

[Devin-M]

…getting dark frames while I catch some zzz’s…

 

[Devin-M]

https://www.speakev.com/attachments/dsc_8781-median-2-2_blended-2-final-gif.151007/

 

[PhysicoRaj]

I took these a couple of nights ago with some handheld 10 second exposures on an iPhone…

You have some serious steady hands... And btw 10s exposure in a little light pollution makes night look like day! I see why NB is the way to pursue this hobby in difficult skies. But there's no solution for clouds :(

They are all stock Sky Watcher Star Adventurer 2i Pro Pack mounts...

Was asking about the DSLRs - two others you bought. Isn't a full spectrum modified camera going to give amazing results for Hubble palette?

 

[Devin-M]

All 3 DSLR’s are standard unmodified D800’s. I don’t have any experience with the modified cameras except clipping in narrowband filters.

I ended up with about 48x 60s RGB shots (2880s) @ 3200iso 600mm f/9, 19x 600s Ha shots (11400s) @ 6400iso, 28x 600s OIII shots (16800s) @ 6400iso and I think around 10x 1200s SII shots (12000s) @ 6400iso or about 12 hours of data total. I was physically there for about 7 hours and did about 4 hours of work in one chunk at the beginning of the session.

 

[Devin-M]

 

[Devin-M]

 

[PhysicoRaj]

Great Shots. What were the shutter actuation counts on the used Nikons?

 

[Devin-M]

My original Nikon which I’ve had since it was new has 186259 shutter actuations. The two I bought used have 29895 and 14358 actuations respectively.

 

[Devin-M]

Here's each of the 4 bands (stacked with some minimal histogram stretching). I subsequently removed the stars from each of the SII, Ha, OIII images after blending with the RGB...

RGB:

Ha:

OIII:

SII:

RGB-SII-Ha-OIII Composite:

 

[Devin-M]

A couple quick tips that could save one from a ruined evening of astrophotography...

Some or all of the Star Adventurer 2i mounts have what I would call a slight software bug that could have you tearing your hair out if you don't know about it. Essentially what happens is this...

The Star Adventurer 2i mounts have an "app" mode that let's you connect to your phone through WiFi, which is useful because you can potentially use the tracker as also an intervalometer that controls your camera exposure times, shutter releases, shot counts, etc (and control it all from your phone -- potentially eliminating the standalone intervalometer)...

Where the "bug" comes into play is this. On at least some Star Adventurer 2i mounts (& I have tested this), suppose you set up an exposure campaign in the "app mode" that shoots suppose 10x 60s shots totaling 10 minutes of exposure time and you run this exposure campaign. So far so good. But suppose several weeks later, you get an external intervalometer, and you don't use the mount in "App" mode but rather just "plain old" star tracker mode... You carefully point and aim the camera, set the exposure and program the external intervalometer to run for 2 hours then you go in your car to get warm... You'll find that low and behold, somehow the "App mode" setting for a 10 minute campaign from weeks ago has turned off the tracking function of the mount after 10 minutes in the "regular old" star tracking mode. The solution is, whenever you expect to be running star tracker ("non-app") mode, make sure the last exposure campaign in "app" mode is set to something like 40 hours, that way when you go to regular old star tracker mode, the motor will be "programmed" to run for at least 40 hours. Probably 16 hours would be enough for any given evening but on second thought, maybe not if you're in Alaska... 6 months??

The other one is quality settings on your camera. Obviously you'll want to be shooting in RAW mode... but if you're doing plate solving through your phone and you have slow internet in the middle of nowhere, you don't want to be fiddling around with RAW files, so at least on my camera I set it up to record both the RAW file and a "small" size jpg (there's also medium and large). So instead of trying to fiddle around with converting and uploading a raw file on your phone, you transfer the small JPG and use that for plate solving ( http://nova.astrometry.net/upload ) while you also retain the RAW file for later processing.

 

[PhysicoRaj]

A couple quick tips that could save one from a ruined evening of astrophotography...

Some or all of the Star Adventurer 2i mounts have what I would call a slight software bug that could have you tearing your hair out if you don't know about it. Essentially what happens is this...

The Star Adventurer 2i mounts have an "app" mode that let's you connect to your phone through WiFi, which is useful because you can potentially use the tracker as also an intervalometer that controls your camera exposure times, shutter releases, shot counts, etc (and control it all from your phone -- potentially eliminating the standalone intervalometer)...

Where the "bug" comes into play is this. On at least some Star Adventurer 2i mounts (& I have tested this), suppose you set up an exposure campaign in the "app mode" that shoots suppose 10x 60s shots totaling 10 minutes of exposure time and you run this exposure campaign. So far so good. But suppose several weeks later, you get an external intervalometer, and you don't use the mount in "App" mode but rather just "plain old" star tracker mode... You carefully point and aim the camera, set the exposure and program the external intervalometer to run for 2 hours then you go in your car to get warm... You'll find that low and behold, somehow the "App mode" setting for a 10 minute campaign from weeks ago has turned off the tracking function of the mount after 10 minutes in the "regular old" star tracking mode. The solution is, whenever you expect to be running star tracker ("non-app") mode, make sure the last exposure campaign in "app" mode is set to something like 40 hours, that way when you go to regular old star tracker mode, the motor will be "programmed" to run for at least 40 hours. Probably 16 hours would be enough for any given evening but on second thought, maybe not if you're in Alaska... 6 months??

Yikes. Will write this down for the future me. I already have an intervalo so probably not going to mess with any tracker mode other than - just track.

The other one is quality settings on your camera. Obviously you'll want to be shooting in RAW mode... but if you're doing plate solving through your phone and you have slow internet in the middle of nowhere, you don't want to be fiddling around with RAW files, so at least on my camera I set it up to record both the RAW file and a "small" size jpg (there's also medium and large). So instead of trying to fiddle around with converting and uploading a raw file on your phone, you transfer the small JPG and use that for plate solving ( http://nova.astrometry.net/upload ) while you also retain the RAW file for later processing.

Good point.

 

[Devin-M]

The moon probably won't be down long enough for me to shoot again til around the evening of 10/31-11/1 so here's a few more lens/OTA tests on the local bird population... two Anna's Hummingbirds and a Lesser Goldfinch... An interesting fact about the Anna's Hummingbird is they are the fastest vertebrate on Earth for their length... faster than a fighter jet relative to length and to sustain this flight they flap their wings 50-60 times per second or more... they can also hover, fly backwards & even upside down…

"The cheetah, the fastest land mammal, scores at only 16 body lengths per second,[5] while Anna's hummingbird has the highest known length-specific velocity attained by any vertebrate."

https://en.wikipedia.org/wiki/Fastest_animals

https://www.speakev.com/cdn-cgi/image/format=auto,onerror=redirect,width=1920,height=1920,fit=scale-down/https://www.speakev.com/attachments/dsc_8674-jpg.151290/

https://www.speakev.com/cdn-cgi/image/format=auto,onerror=redirect,width=1920,height=1920,fit=scale-down/https://www.speakev.com/attachments/dsc_8758-jpg.151291/

https://www.speakev.com/cdn-cgi/image/format=auto,onerror=redirect,width=1920,height=1920,fit=scale-down/https://www.speakev.com/attachments/dsc_8735-jpg.151292/

 

[Devin-M]

It’s predicted that Fri Nov 5th will be the 1st time since Oct 10th that the moon will be down til at least 3am and no cloud… fingers crossed… I’ve also realized there’s only about 1 week a month where the moon is down from early evening until 3am.

 

[PhysicoRaj]

Caught some signal from Saturn. I definitely can improve over this, because this is my first planetary image and there was a layer of clouds / haze that I shot through, which will have certainly pushed the quality down. I believe I can get the gap between the rings and the planet clearly next time.

 

[sophiecentaur]

Planetary images are best with very long lenses (2,000mm) to fill more of the sensor.

 

[PhysicoRaj]

Planetary images are best with very long lenses (2,000mm) to fill more of the sensor.

This one was at 2100mm, but the sensor is a DSLR which is bigger than the planetary webcams so the size of the planet relative to the frame is small.

Also, the lens and Barlow quality is not that great, so the rings are not clear. I will probably move to a used bigger scope and better optics, I'm just fiddling around with the present one till I save up some bucks. At least I was able to partially resolve the rings, let's see how much juice I can extract from this scope while I'm at it.

Edit: BTW, do you think looking at the image that my barlow is actually 3x?
Image size: 1920x1080 (3.7 micron pixel)
Cropped to: 1000x1000
Objective FL: 700mm
Barlow: 3x (?)

I have seen some images of Saturn at 2000mm like this and it is much larger. Even though that image is 1280x720, the proportion by which the planet is bigger than mine seems to indicate that my Barlow could be a 2x.

 

[sophiecentaur]

The rule is “Spend spend spend” I’m afraid.

 

[PhysicoRaj]

The rule is “Spend spend spend” I’m afraid.

It is rather scary. But now I am starting to believe that Celestron might have kind of duped me with this scope. Check the edit on my last post.

Even without a barow, my aperture seems to have a dawes limit resolution that is larger than what the focal length can extract. On top of it they gave a Barlow which seems ridiculous unless my math is wrong.

 

[Devin-M]

Image size: 1920x1080 (3.7 micron pixel)
Objective FL: 700mm
Barlow: 3x (?)

In my earlier test shot of Saturn which appeared to have similar detail, I was shooting at 1/3.5 the focal length (600mm f/9), but the imaging sensor on the D800 was 7360x4912… 3.8x the sensor resolution… The following shot (which I posted before) has been cropped & also upscaled with interpolation.

https://www.speakev.com/attachments/saturn_stacked_mono_green2-gif.150147/
If you crop the image before uploading it, the planet will have a larger final display size on the web page without sacrificing resolution. This website is downsizing your final image to below 1920x1080 when you upload it to conserve bandwidth.

For best final display you’ll want to determine what size this website downsizes your final image to, and then do a 100% crop at those same dimensions before you upload it.

You could also host the image elsewhere and include a link to it to avoid the final downsizing that occurs after you upload it.

 

[PhysicoRaj]

In my earlier test shot of Saturn which appeared to have similar detail, I was shooting at 1/3.5 the focal length (600mm f/9), but the imaging sensor on the D800 was 7360x4912… 3.8x the sensor resolution… The following shot (which I posted before) has not only been cropped but also upscaled with interpolation...

I have cropped a bit - just checked that the image I have uploaded is 1000x1000. Note that I am not worried about planet resolution, but the size of the planet in relation to the frame size. But me cropping it should only give an even bigger planet. And your frame size being 3.8x the size of mine before cropping, and 3.5 times lower focal length, I should have definitely gotten a bigger relative size of the planet. Something definitely seems off.

 

[Devin-M]

I think it’s as simple as cropping out the empty space around the planet before uploading and what remains will be displayed at a larger apparent size.

 

[Devin-M]

Image size: 1920x1080 (3.7 micron pixel)

Doesn’t your camera shoot in RAW mode higher than 1920x1080?

 

[Devin-M]

And your frame size being 3.8x the size of mine before cropping, and 3.5 times lower focal length, I should have definitely gotten a bigger relative size of the planet.

I’m not sure this is all accurate… we haven’t factored the different sensor size… I was using a 35mm sensor.

 

[PhysicoRaj]

I’m not sure this is all accurate… we haven’t factored the different sensor size… I was using a 35mm sensor.

I use a crop sensor, 1.6x. Now the more cropped it is the bigger my planet has to be, so I'm even more suspicious now.

Doesn’t your camera shoot in RAW mode higher than 1920x1080?

It does, but the FPS is low. I use a lower size to get more FPS.