Testing Celestron next star 8SE reflector

[Andysu]

Testing Celestron next star 8SE reflector. Its a model that has been out for many years and still in current production.
Attached Canon DLR to it with few pictures and video of the moon. I many more steps to go before I can get it fitted with CCD. The nights depend on the weather cloudy as not much one can do? Other than wait?

Still no sign of lunar rover or mirror for the laser? Guess I need a bigger scope. I think nasa has a Hubble for sale soon. let me see if they take cash or cheque?
Be intresting see what this James Webb scope will show once its in position.

 

[Blumlein 88]

I've got an old, C8 on a pretty good old mount. Here is a pic just shot by placing a small digicam up to the lens. Alas, someone broke into the garage where it was stored and stole all my eyepieces. I'd spent years collecting the ones I had. I've never replaced them. I need to get some more or sell the old scope. The slightly odd shape on the lower right is because the view of the scope was cutting that off due to my not holding the camera centered perfectly.

 

[Andysu]

You have a filter on the camera. Nice depth of detail. Sorry your garage got busted in, the bastards. I saw the moon as it was I think my image is bit soft and I think also need filter as looking though the 25mm eye piece that came with it, was too bright sensitive that I almost lost my night-vision in left eye. Green filter is what I want thou I can use any and may do cheap using colour gel plastic cut to size. It's a bit of hump carrying down outside and set-up for now takes 10 minutes. I guess once I get into more of the deep astrophotography with laptop would take longer. Lousy weather for wintertime. I can bare only less than hour.

 

[Blumlein 88]

You have a filter on the camera. Nice depth of detail. Sorry your garage got busted in, the bastards. I saw the moon as it was I think my image is bit soft and I think also need filter as looking though the 25mm eye piece that came with it, was too bright sensitive that I almost lost my night-vision in left eye. Green filter is what I want thou I can use any and may do cheap using colour gel plastic cut to size. It's a bit of hump carrying down outside and set-up for now takes 10 minutes. I guess once I get into more of the deep astrophotography with laptop would take longer. Lousy weather for wintertime. I can bare only less than hour.

Yeah, I don't tolerate those cold nights like I used to. Of course that is always the best time to be out gazing!

 

[Andysu]

Well cold nights and thinking of homeless people, no one or no animal should have to stay out in the cold. But space that surrounds our, that surrounds this planet is vastly cold -455f. yet how was we, that we later though evolution to develop, advanced human mind for which without all, this that humankind as created wouldn't even exist. I guess in some sense that "we, us, all" are living on a "homeless pale blue dot planet" by an infinity of blackness/darkness.

How we each see the universe. I see it as empty blackness with stars/suns nebula's where light shines onto blankets of gases/dust and produces wondrous colours in that , real pure black than blacks of pureness over a Oled tv or projector. I' amazed when I see a friends pictures of Rosette Nebula.

 

[Andysu]

Moon picture taken with a Fuji finepix digital camera, tripod mounted time-stamp on the picture 2014 and moon even looks same today present as did back then. Also looks bit like your picture as it has brownish colour.

 

[SIY]

Every time I think, "I need to get a new telescope," I look at the actual observatory behind our house and lament.

 

[pkane]

Testing Celestron next star 8SE reflector. Its a model that has been out for many years and still in current production.
Attached Canon DLR to it with few pictures and video of the moon. I many more steps to go before I can get it fitted with CCD. The nights depend on the weather cloudy as not much one can do? Other than wait?

View attachment 179361

View attachment 179362

Still no sign of lunar rover or mirror for the laser? Guess I need a bigger scope. I think nasa has a Hubble for sale soon. let me see if they take cash or cheque?
Be intresting see what this James Webb scope will show once its in position.
View attachment 179363

Nice! May need to be collimated if you’ve not done that already.

Here’s a B&W one I took with a small refractor a few decades ago:

 

[audio2design]

Every time I think, "I need to get a new telescope," I look at the actual observatory behind our house and lament.

When you see amateurs with 20 and 24" scopes with remote observatories it can be daunting. Has computational photography reached amateur astronomy yet?

 

[pkane]

When you see amateurs with 20 and 24" scopes with remote observatories it can be daunting. Has computational photography reached amateur astronomy yet?

Amateurs have been doing digital photography (CCD and CMOS) for well over 20 years. They produced a number of discoveries, including supernovae hunting, occultation measurements and exoplanet detection. Some do spectral analysis, but most do “pretty” imaging. Professional astronomers often collaborate with amateurs.

 

[audio2design]

Amateurs have been doing digital photography (CCD and CMOS) for well over 20 years. They produced a number of discoveries, including supernovae hunting, occultation measurements and exoplanet detection. Some do spectral analysis, but most do “pretty” imaging. Professional astronomers often collaborate with amateurs.

I built my first cooled CCD in the earlyish 90's based on a TI part at the time that was popular for DIY astrophotography. I think by the mid-90's you could buy half decent ones based on Kodak sensors. They were a major step up as you could do long integration. Moved from the country to the burbs when the kids started school and the hobby no longer made sense. I have thought of putting a setup at the cottage, but would need somewhere safe for storage.

I saw the most recent Leica (mind you it as $9,000) was claiming a 1 hour maximum shutter speed.

 

[pkane]

I built my first cooled CCD in the earlyish 90's based on a TI part at the time that was popular for DIY astrophotography. I think by the mid-90's you could buy half decent ones based on Kodak sensors. They were a major step up as you could do long integration. Moved from the country to the burbs when the kids started school and the hobby no longer made sense. I have thought of putting a setup at the cottage, but would need somewhere safe for storage.

I saw the most recent Leica (mind you it as $9,000) was claiming a 1 hour maximum shutter speed.

Cooled CCD (or more recently, CMOS) is common now, and for a lot less than Leica including in large sensor format. Some have quantum efficiency (QE) of over 90%, and low read and thermal noise, which makes them perfect for long exposures. With modern image processing software, you can stack as many images as you want to improve SNR. The longest exposure I've used is around 30 minutes or so, but with stacking, taking many dozens of exposures of the same area, the total exposure of 24 hours or more is not that hard. The real limitation is the fact that all amateurs are located at the bottom of a pool of air, looking through a thick and turbulent atmosphere that blurs everything. Of course, good optics and telescope mounts capable of sub-arcsecond tracking are also still not cheap.

 

[dwkdnvr]

I built my first cooled CCD in the earlyish 90's based on a TI part at the time that was popular for DIY astrophotography. I think by the mid-90's you could buy half decent ones based on Kodak sensors. They were a major step up as you could do long integration. Moved from the country to the burbs when the kids started school and the hobby no longer made sense. I have thought of putting a setup at the cottage, but would need somewhere safe for storage.

I saw the most recent Leica (mind you it as $9,000) was claiming a 1 hour maximum shutter speed.

Astro is another hobby I don't have time for, but the last 10-ish years has seen a complete revolution in the availability of moderately priced and very capable dedicated astronomy cameras. There is a wide variety of sensor sizes available ranging from tiny security camera sizes up to 35mm full frame; the larger sizes are generally using the same sensors as in consumer mirrorless cameras, but specialized for astro use. Cooled cameras are now very common and only slightly more expensive than uncooled. Plus, there are monochrome versions that omit the Bayer matrix for better resolution and sensitivity; compared to what was available when I first started paying attention around 05 or so, it's pretty amazing.

A huge benefit of the new CMOS cameras is very low read noise, meaning that you no longer need long single-frame exposure times to get the best results. Even the dedicated imagers rarely have to go over 5 minute exposures, and 1-2 min are extremely viable. Total integration time is still long, but shorter per-frame exposures really lower the demands on the mount compared to having to do 20-30 min exposures.

A somewhat niche pursuit that I find very interesting may help in your surburban location. It's called 'EAA' for 'electronically assisted astronomy', and the goal is simply to 'see more than you can through the eyepiece' rather than create visually amazing astrophotos. It uses short exposures (1s - 30s typically) plus special alignment/stacking software to very quickly give you a decent rendering of celestial objects. It's pretty remarkable what can be done with only 1-2 minutes of exposure on many of the common DSOs. The kicker is that due to the short exposures you can use an Alt-Az mount rather than having to drag out and align an equatorial. It's also amazing what can be done from light-polluted skies - there are folks posting very decent images taken from places like LA metro.

 

[audio2design]

Cooled CCD (or more recently, CMOS) is common now, and for a lot less than Leica including in large sensor format. Some have quantum efficiency (QE) of over 90%, and low read and thermal noise, which makes them perfect for long exposures. With modern image processing software, you can stack as many images as you want to improve SNR. The longest exposure I've used is around 30 minutes or so, but with stacking, taking many dozens of exposures of the same area, the total exposure of 24 hours or more is not that hard. The real limitation is the fact that all amateurs are located at the bottom of a pool of air, looking through a thick and turbulent atmosphere that blurs everything. Of course, good optics and telescope mounts capable of sub-arcsecond tracking are also still not cheap.

I don't consider QE overly critical once you are much past 60% which we have been at for a while, but that depends on what type of imaging you would be interested in. My interest was always long exposure faint object, so typically dark current/read-noise limited. It seems like most of the cameras targeting that market are still based off fairly old CCD sensors but the price is much better, <$2,000, with better ones still <$3K. Stacking is great for increasing SNR, but better to have inherently low noise. It does help you with Shot noise at the same time, so there is that benefit. w.r.t. computational photography, I was thinking more like amateur guide stars, or perhaps AI techniques to deal with that big pool of turbulent air.

 

[SIY]

I'd love to try IR astronomy. I think I still have some MCT detectors in the garage, and LN2 is easy to get here... If only my wife would do the right thing and win the lottery.

 

[Martin]

I used to own a Celestron C90 when I lived in the middle of 320 acres of avocado trees in agricultural north San Diego county. I'd sit out at night and peer at the stars. Saw some amazing views of the moon, Mars, Jupiter, Saturn, Andromeda and many nebula with that little 1000mm telescope. I wish I still lived somewhere dark. Someday maybe...

Martin

 

[audio2design]

A huge benefit of the new CMOS cameras is very low read noise, meaning that you no longer need long single-frame exposure times to get the best results. Even the dedicated imagers rarely have to go over 5 minute exposures, and 1-2 min are extremely viable. Total integration time is still long, but shorter per-frame exposures really lower the demands on the mount compared to having to do 20-30 min exposures.

A somewhat niche pursuit that I find very interesting may help in your surburban location. It's called 'EAA' for 'electronically assisted astronomy', and the goal is simply to 'see more than you can through the eyepiece' rather than create visually amazing astrophotos. It uses short exposures (1s - 30s typically) plus special alignment/stacking software to very quickly give you a decent rendering of celestial objects. It's pretty remarkable what can be done with only 1-2 minutes of exposure on many of the common DSOs. The kicker is that due to the short exposures you can use an Alt-Az mount rather than having to drag out and align an equatorial. It's also amazing what can be done from light-polluted skies - there are folks posting very decent images taken from places like LA metro.

Large parallelism in CMOS and architecture keeps the analog bandwidths low so you can get very good read noise at reasonable readout rates. ~1 electron read noise as a realistic number certainly changes the ball game. Faster integration time also means less effects from turbulence.

Will have to look more into this EAA. That was what my question was more about. Sounds very interesting. I would probably still want to align an equatorial though. Call it a vinyl thing

 

[pkane]

I don't consider QE overly critical once you are much past 60% which we have been at for a while, but that depends on what type of imaging you would be interested in. My interest was always long exposure faint object, so typically dark current/read-noise limited. It seems like most of the cameras targeting that market are still based off fairly old CCD sensors but the price is much better, <$2,000, with better ones still <$3K. Stacking is great for increasing SNR, but better to have inherently low noise. It does help you with Shot noise at the same time, so there is that benefit. w.r.t. computational photography, I was thinking more like amateur guide stars, or perhaps AI techniques to deal with that big pool of turbulent air.

Large QE isn't critical, but beneficial, especially if you're trying to do faint object or narrow-band imaging (mostly what I do). There are AI-like algorithms that learn to guide your mount and help compensate for mount tracking errors. I've yet to see an AI-based algorithm for compensating for atmospheric turbulence. There are some adaptive-optic devices available for amateurs, and these help. But they are nothing like the professional laser-guided AO systems with deformable mirrors. They can only compensate for very slow moving air masses.

I suspect this is not the right forum to discuss these things, though

 

[audio2design]

Interesting quick look at "state of the art" consumer: https://www.atik-cameras.com/product/atik-16200/, based on CCD. 9e dark current, 0.25 electrons / second at 0C. sCMOS: 1 e dark current, 0.007 electrons/second (-40C cooled). Assuming the 16200 0.25e/sec is at 0C sensor, at -40C, it would get similar performance.

 

[dwkdnvr]

Large parallelism in CMOS and architecture keeps the analog bandwidths low so you can get very good read noise at reasonable readout rates. ~1 electron read noise as a realistic number certainly changes the ball game. Faster integration time also means less effects from turbulence.

Yes, lowering the cost of a bad frame can be a pretty significant benefit. The planetary imaging guys in particular have benefited greatly from the low read noise - they now shoot what is basically video streams of 100 frames/sec or more, and then brute-force the frame quality analysis to take the best X frames to mitigate the effects of atmospheric turbulence.

Will have to look more into this EAA. That was what my question was more about. Sounds very interesting. I would probably still want to align an equatorial though. Call it a vinyl thing

Cloudy Nights is not surprisingly the go-to place for getting started in EAA. https://www.cloudynights.com/forum/73-electronically-assisted-astronomy-eaa/ . The 2 most common approaches are using SharpCap (windows software), or the ZWO Asi Air (basically a Pi4 running custom variants of the Kstars/Ekos open source code with some (I think) proprietary camera control and alignment/stacking code.)

Using an equatorial is certainly better overall, particularly if you get into narrow-band, but the fact that it isn't required certainly lowers the barrier to entry.