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Sony A7S - Viable for EAA?

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#51 schwim

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Posted 26 June 2015 - 11:53 AM

 

Via the API, can you control the A7s via USB on your desktop computer?

 

 

Not via USB. You need to use a private WiFi connection with the camera. You'll need to run the Smart Remote Control app. This will start the API up on the camera and allow this private connection. I don't know why they do it only with a private network, seems short sighted if you ask me. If you want to remain connected to an existing wifi network, you'll need to get a wifi usb adapter to connect to it.



#52 CHAPSKINS

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Posted 26 June 2015 - 03:52 PM

 

 

Via the API, can you control the A7s via USB on your desktop computer?

 

 

Not via USB. You need to use a private WiFi connection with the camera. You'll need to run the Smart Remote Control app. This will start the API up on the camera and allow this private connection. I don't know why they do it only with a private network, seems short sighted if you ask me. If you want to remain connected to an existing wifi network, you'll need to get a wifi usb adapter to connect to it.

 

 

Hmm, wouldn't using WiFi introduce noise?



#53 schwim

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Posted 26 June 2015 - 04:49 PM

 

 

Hmm, wouldn't using WiFi introduce noise?

 

 

Anything is possible. I'm no EE, but I wouldn't the sensor need to be sensitive to the microwave frequencies used by the wifi radio?



#54 ccs_hello

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Posted 26 June 2015 - 04:58 PM

WiFi is transmitting IP wirelessly.  It's digital data. No need to worry about interference.



#55 bwallan

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Posted 26 June 2015 - 06:21 PM

Another option (or two) for remote control, tethering and viewing images:

 

Via Adobe Lightroom:

 

http://briansmith.co...ony-a7-a7r-a7s/

 

Sony Remote Camera Control and Adobe Lightroom.  You can set presets to apply to new images as they show up in the view folder.

 

 

And via Capture One:

 

http://briansmith.co...hering-support/

 

bwa


Edited by bwallan, 26 June 2015 - 06:23 PM.

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#56 Alex Parker

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Posted 27 June 2015 - 07:58 PM

I keep going back to member jdbastro's work with the unmodded Sony A7S because he achieves really nice, straight out of the camera, single jpeg images in 30 seconds or less with NO post processing.  He does have nice glass and a dark site, but you still have to be in awe of his results with this camera.  He also does a lot of work with image intensifiers, but I enjoy the stuff from just the A7S.  Here is a link with many single image posts and it also includes a link to one of his image albums.

 

http://www.cloudynig...-from-sony-a7s/

 

The only problem with past posts in the EAA forum involving the Sony A7S had to do with the posting of stacked images with significant post processing.  As long as this is explained with the posted image, I have no problem with it.  But then someone not familiar with astro imaging might expect to get such results straight from the camera in near real time observing mode.

 

I am all for cameras like the Sony A7S for use in EAA.  I hope we see a flood of similar cameras from all of the mirrorless and dslr manufacturers.

That's nice glass indeed.  And very cool images.  I hope a reasonable EAA workflow can be figured out for these cameras.



#57 bwallan

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Posted 27 June 2015 - 09:50 PM

 

I keep going back to member jdbastro's work with the unmodded Sony A7S because he achieves really nice, straight out of the camera, single jpeg images in 30 seconds or less with NO post processing.  He does have nice glass and a dark site, but you still have to be in awe of his results with this camera.  He also does a lot of work with image intensifiers, but I enjoy the stuff from just the A7S.  Here is a link with many single image posts and it also includes a link to one of his image albums.

 

http://www.cloudynig...-from-sony-a7s/

 

The only problem with past posts in the EAA forum involving the Sony A7S had to do with the posting of stacked images with significant post processing.  As long as this is explained with the posted image, I have no problem with it.  But then someone not familiar with astro imaging might expect to get such results straight from the camera in near real time observing mode.

 

I am all for cameras like the Sony A7S for use in EAA.  I hope we see a flood of similar cameras from all of the mirrorless and dslr manufacturers.

That's nice glass indeed.  And very cool images.  I hope a reasonable EAA workflow can be figured out for these cameras.

 

But only the Zeiss 200mm f2 is really a fast lens.  The rest are pretty standard imaging focal ratios...

 

bwa



#58 chasing photons

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Posted 27 June 2015 - 10:33 PM

 

 

I keep going back to member jdbastro's work with the unmodded Sony A7S because he achieves really nice, straight out of the camera, single jpeg images in 30 seconds or less with NO post processing.  He does have nice glass and a dark site, but you still have to be in awe of his results with this camera.  He also does a lot of work with image intensifiers, but I enjoy the stuff from just the A7S.  Here is a link with many single image posts and it also includes a link to one of his image albums.

 

http://www.cloudynig...-from-sony-a7s/

 

The only problem with past posts in the EAA forum involving the Sony A7S had to do with the posting of stacked images with significant post processing.  As long as this is explained with the posted image, I have no problem with it.  But then someone not familiar with astro imaging might expect to get such results straight from the camera in near real time observing mode.

 

I am all for cameras like the Sony A7S for use in EAA.  I hope we see a flood of similar cameras from all of the mirrorless and dslr manufacturers.

That's nice glass indeed.  And very cool images.  I hope a reasonable EAA workflow can be figured out for these cameras.

 

But only the Zeiss 200mm f2 is really a fast lens.  The rest are pretty standard imaging focal ratios...

 

bwa

 

 

 

To get close-ups of smaller DSOs with the full frame, or even APS-C cropped, A7S, you need larger aperture, longer focal length optics.  This makes it difficult to achieve a fast optical system that is favored for EAA.  In other words, the advantage that the A7S has in increased sensitivity with larger sized pixels is countered by slower or bigger optics needed to get closer and maintain good resolution and image scale.  It can be a tough balancing act to get all of the components of a good EAA system to work well together.  I have yet to find a system that I would be happy with or wouldn't cost a fortune and weigh a ton.



#59 Don Rudny

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Posted 28 June 2015 - 12:29 AM

Todd,

 

I think that's what I was saying in this post.

 

http://www.cloudynig...-eaa/?p=6647220

 

Did you ever consider a Lodestar with Lodestar Live software?



#60 Relativist

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Posted 28 June 2015 - 12:44 AM

No, we do not know if that is really true, you might be simply able to just crop the center as needed, or increase the focal length & ISO. We do not yet know how to compare the Lodestars & Mallincams with or without gain which use CCDs to the A7s and it's very high ISO capabilities. The A7s is very viable for EAA especially now that we have AT/DSS.



#61 Dom543

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Posted 28 June 2015 - 01:12 AM

Visual observers have an array of eyepieces. So that they can pick the most suitable one depending on the object they observe. In EAA, our eyepiece is our camera. We should also be allowed to have an array of cameras so that we can use the right one for each object. In particular, as a Lodestar is substantially smaller, lighter and less expensive than e.g. a 21mm Ethos.

 

We should start the CFO education program right now!

 

Clear Skies!

--Dom



#62 Don Rudny

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Posted 28 June 2015 - 01:12 AM

Sorry, Curtis.  I don't understand your post.  What do we not know if that is really true?  How do we not know how to compare Mallincams and Lodestars to the A7s? And, finally, no one said that the A7s was not viable for EAA, but where is the evidence that it is very viable for EAA as you say?



#63 CHAPSKINS

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Posted 28 June 2015 - 02:32 AM

No, we do not know if that is really true, you might be simply able to just crop the center as needed, or increase the focal length & ISO. We do not yet know how to compare the Lodestars & Mallincams with or without gain which use CCDs to the A7s and it's very high ISO capabilities. The A7s is very viable for EAA especially now that we have AT/DSS.

 

Hi Curtis

 

What does AT and DSS mean? I'm assuming it's software :)



#64 mclewis1

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Posted 28 June 2015 - 09:31 AM

AstroToaster and Deep Sky Stacker. Either of these allow you to stack multiple shorter exposures for better quality images. Some of the differences are in the workflow and how automated the stacking process becomes.



#65 ccs_hello

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Posted 28 June 2015 - 10:54 AM

Re: (the argument of) A7s is using a full frame sized thus placed a high optical demand on lens/OTA

 

Allow me to state my view on this...

We get the benefit of modern mass-production goods for a lower price ($2500), while if we use niche, purposely mode/purposely modified good,

we play the low-volume, niche-market price  

<-- hint: look at ICX285/825 based (type-1/1.5"), ICX428/429 based (type-1/2"), and even ICX828/829 based (also type-1/2"), some are not even active cooled

 

Granted FF size (to me) is too much, not have enough heart to find the great optics/OTA to mate with it.  Fortunately, A7S has a crop sensor mode (makes it APS-C sized but less spatial resolution.)

If SONY, Oly, Panny, Nikon, or someone else convince SONY to make an APS-C sized or Four-Thirds sized crop version of the sensor, with a $1000-$1200 price tag, that will be a hot sell, (other than folks who are trained to follow the mega-pixel race and pay big bucks more just more pixels.)

 

We the astro guys want more real-estate (larger sensor), not tiny pixels!  If some marketing guys can listen...

 

Back to our normally scheduled A7s program...

 

Clear Skies!

 

ccs_hello 



#66 bwallan

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Posted 28 June 2015 - 01:06 PM

I always get a kick out of following EAA discussions...

 

EAA, by definition, is an image captured off an imaging device and displayed realtime, i.e.: an image intensifier is a perfect example.  At one time EAA was equivalent to astro-video, i.e.: high gain video.  However, EAA has morphed into images integrated (stacked) and processed in Mallincam devices/software and displayed in pseudo realtime (what is "realtime"?  Debated to no end!), to now discussing how best to use Deep Sky Stacker (DSS) to process and display an image in pseudo realtime.  Has "realtime" entered the realm of actual astrophotography?

 

Pretty soon EAA guys/gals will be aligning, stacking and processing images like astro-imagers.  Using DSS (the very name brings EAA out of the closet) is really pushing the envelope of EAA, but maybe not since all astrophotography today is Electronically Assisted Astronomy...  At least I don't see too many people still shooting film.  And with the processing speed of computers increasing with every new release it may well be possible to align, stack and process images in "realtime", whatever that might be?

 

And the discussion carries on...  It is fun to watch :)

 

bwa

 

P.S.: http://www.cloudynig...-controversial/ is another topic from Feb 2015 on this subject.



#67 schwim

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Posted 28 June 2015 - 01:55 PM

I always get a kick out of following EAA discussions...

 

...

 

And the discussion carries on...  It is fun to watch :)

 

bwa

 

 

Indeed. For me, it really came to the fact that I can't see much in the light polluted area in which I live. I looked for "assitance" via electronic measures so I don't need to drive two or more hours to a reasonably dark sky.

 

Integration on video vs. exposure time - the end result is I have to wait a short period for my image to appear. 

 

Also, one does not need to stack. Sure, it helps get rid of some of the noise and increases image quality, but it's not *required*. I rarely stack because I'm not guiding and image shift just messes things up. 

 

So, maybe EAA is just "Astrophotography Lite". 

 

I will now duck. :)


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#68 chasing photons

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Posted 28 June 2015 - 02:02 PM

Don and Curtis and ccs_hello and bwa,

 

In general, I have ruled out all small (1/3 and 1/2) format, large pixel sensors.  With the tiny FOV, they work OK for close-ups of smaller DSOs but not so well for the larger, extended objects.  I happen to like nice star fields surrounding the objects.  Lodestars and Mallincams do not do stars well, at least for my tastes.  Yep, that's right, I like pretty pictures.  Nope, I don't want to spend a lot of time with astrophotography.  Yep, I do want almost immediate results.  Nope, I am not happy with the current state of EAA.  Yep, I am stuck somewhere in the middle, between the current state of EAA and astrophotography.  The Sony A7S is breaching this area, but like everything else, it doesn't do everything well.  With that huge sensor area, it is fine for the larger, extended objects using relatively small, fast optics.  But to maintain a relatively fast focal ratio to compliment the high sensitivity of those large pixels, it requires the larger apertures and/or longer focal lengths to do well with the smaller DSOs.

 

Here is an example of what I am talking about.  Going back to jdbastro's A7S images, here are two examples that show the extremes.  

  

First one is the Ring Nebula, a tiny DSO that requires either significant magnification or an equally tiny image sensor.  Jdbastro uses a 10 inch OTA at a slow f/12 focal ratio to obtain sufficient magnification.  The APS-C crop field of view is small at roughly 27 minutes x 18 minutes at 0.6 arcseconds per pixel, maybe a bit oversampled for EAA tastes.  But this fine image scale will allow some more cropping (enlarging) before the image becomes pixilated.  Very pretty, but still tiny and more stars than even I need.  Fortunately, the 1.5 arcminute diameter Ring is bright enough, even at the slow focal ratio, to complete the image in 30 seconds.

 

http://s940.photobuc...tml?sort=3&o=15

 

The second example shows the other extreme.  The APS-C cropped image contains both the Lagoon and Trifid Nebulae using a smallish, 3.5 inch OTA at a fast f/4.5.  The field of view is huge at roughly 3.3 degrees x 2.2 degrees at a rather undersampled 4.3 arcseconds per pixel.  The two nebulae are tiny in the image and would not fare very well with much more cropping (enlarging) before the image would get quite pixilated. 

 

http://s940.photobuc...tml?sort=3&o=23

 

And here are the results.  The Sony A7S does well on smaller DSOs as long as the optics are quite large, the larger the better to get the necessary magnification to fill up that huge sensor.  At the opposite end, the Sony A7S does well with smaller, faster optics as long as the subject matter is large, extended DSOs surrounded by large star fields.  Otherwise, plan on longer exposures to offset the slower focal ratios that will be required with smaller optics.  The Sony A7S is ideally suited for very large optics that are also very fast... in other words, expensive glass and mounts.

 

When I get time, I intend to start one or more threads to discuss what I think is the Goldilocks zone for EAA systems, at least for me.  Think medium… medium size sensors with medium size pixels and medium size optics with medium size mounts, all at a price/performance ratio that I can tolerate.


Edited by chasing photons, 28 June 2015 - 03:00 PM.


#69 ccs_hello

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Posted 28 June 2015 - 02:58 PM

re: is it imaging?

 

My view, other than using the Image Intensifier tube method, most of them are imaging using some type of image sensors.

 

However, for political correctness, let me add the qualifier: we are doing the draft-mode imaging.

"Draft mode", in photography, is known as frame-n-focus mode.  The purpose is getting the image formed as quick as possible, and allowing S/N to go low enough but can "see" something.

 

Since recording it (photograph it) is not the goal in frame-n-focus, near-realtime is, multiple tricks can be applied, (consider it has certain degrees of art involved),

people call that "viewing" so no one is unhappy.

 

Clear Skies!

 

ccs_hello


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#70 bwallan

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Posted 28 June 2015 - 07:07 PM

Don and Curtis and ccs_hello and bwa,

 

In general, I have ruled out all small (1/3 and 1/2) format, large pixel sensors.  With the tiny FOV, they work OK for close-ups of smaller DSOs but not so well for the larger, extended objects.  I happen to like nice star fields surrounding the objects.  Lodestars and Mallincams do not do stars well, at least for my tastes.  Yep, that's right, I like pretty pictures.  Nope, I don't want to spend a lot of time with astrophotography.  Yep, I do want almost immediate results.  Nope, I am not happy with the current state of EAA.  Yep, I am stuck somewhere in the middle, between the current state of EAA and astrophotography.

...

Been there, done that.  I sold off my Mallincam's and went back to normal astrophotography...  Because I also like pretty pictures and the EAA of that era wasn't doing it for me.  Maybe a new era has evolved/arrived?

 

bwa


Edited by bwallan, 28 June 2015 - 10:03 PM.


#71 Dom543

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Posted 29 June 2015 - 12:57 PM

Indeed. For me, it really came to the fact that I can't see much in the light polluted area in which I live. I looked for "assitance" via electronic measures so I don't need to drive two or more hours to a reasonably dark sky.

 

Integration on video vs. exposure time - the end result is I have to wait a short period for my image to appear. 

 

Also, one does not need to stack. Sure, it helps get rid of some of the noise and increases image quality, but it's not *required*. I rarely stack because I'm not guiding and image shift just messes things up. 

 

So, maybe EAA is just "Astrophotography Lite". 

 

I will now duck. :)

 

re: is it imaging?

 

My view, other than using the Image Intensifier tube method, most of them are imaging using some type of image sensors.

 

However, for political correctness, let me add the qualifier: we are doing the draft-mode imaging.

"Draft mode", in photography, is known as frame-n-focus mode.  The purpose is getting the image formed as quick as possible, and allowing S/N to go low enough but can "see" something.

 

Since recording it (photograph it) is not the goal in frame-n-focus, near-realtime is, multiple tricks can be applied, (consider it has certain degrees of art involved),

people call that "viewing" so no one is unhappy.

 

Clear Skies!

 

ccs_hello

 

I don't want to hijack this thread from the Sony A7S. But since the quoted posts came up on this thread and Brian is an "independent" observer, whose perspective encompasses both astrophotography and what we call EAA, I add one of my observations here.

 

I agree with swim and ccs_hello thet once computers are used, EAA becomes a special subarea of astro imaging. Both "Astrophotography Lite" or "Draft Mode Imaging" are adequate monikers. Distinguishing features mentioned above are moderate length (up to a couple of minutes) total exposure time, direct in-line "live" processing (i.e. no post processing of saved captures) and the acceptance of less than publication quality images that are not assumed to allow substantial enlargements.

 

My observation is that there is one more distinguishing feature that is also one of the main reasons why EAA images are not suitable for posting on astrophotography forums. In order to obtain images that are enjoyable immediately on the screen, we use exposure times, gain and brightness settings that would qualify as gross overexposure in the astrophotography world. We accept that stars and bright areas are blown out, in exchange for the fainter areas also be visible directly on the real-time screen.

 

If one tries to post these images on a beginner astrophotography forum, one immediately gets the friendly advice to dial back exposure and avoid overexposure. For this reasons any claims saying that a camera is dual purpose, the images can be viewed for immediate enjoyment and, at the same time, saved for future post processing, are misleading. It is possible to generate captures that are enjoyable real-time and is possible to save other captures that are suitable for post-processing later. But those will be two different sets of captures with different initial on-camera parameters.

 

I posted this on this Sony A7S thread because I would be interested to hear, if this observation also applies to the Sony A7S. As far as I can see from descriptions, that camera is capable of simultaneously saving both raw image files, that are supposed to be "un-cooked", and jpg files that are the results of the camera's internal processing. 

 

Thank you and Clear Skies!

--Dom


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#72 bwallan

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Posted 29 June 2015 - 02:38 PM

I don't want to hijack this thread from the Sony A7S. But since the quoted posts came up on this thread and Brian is an "independent" observer, whose perspective encompasses both astrophotography and what we call EAA, I add one of my observations here.

...

I posted this on this Sony A7S thread because I would be interested to hear, if this observation also applies to the Sony A7S. As far as I can see from descriptions, that camera is capable of simultaneously saving both raw image files, that are supposed to be "un-cooked", and jpg files that are the results of the camera's internal processing. 

 

Thank you and Clear Skies!

--Dom

 

 

Dom,

 

As I've mentioned on previous forums I have used the A7S for EAA in its simplest format; simply outputting the Liveview screen to a monitor as shown below.  This works very well for some good old fashioned community outreach; 10-30 sec. exposures at ISO's in the order of 6400-12800.  Not the greatest quality but more than adequate for a 7" monitor with Liveview resolution.  I've used similar configurations on everything from an 6.5mm fisheye to a 2700mm Mak.  Most recently was training a bunch of Girl Guides for their Astronomy badge.  On that occasion I projected the A7S's image on the white garage door.  I have also captured this output to a Sony Video Recordable DVD Drive (VRD-MC1); the same unit I used to copy all my old Beta/VHS's to DVD.

 

Of course using the output from the Liveview screen does incorporate in-camera processing/settings (Styles, Profiles, Long Exposure/High ISO/Multi-Frame Noise Reduction, etc.); essentially the JPG output from the camera.  Also, going this approach allows one to zoom into an image to highlight small objects, i.e.: the Ring nebula, the Whirlpool galaxy, Globula clusters, double/triple stars, planets, specific features on the Moon, etc.

 

AVX%252CAT65EDQ%252CFSA7S%252CMonitor%25

 

All the A7 series cameras are capable of simultaneously saving RAW and JPG files, although I'm not too sure I'd say the RAW file was uncooked?  Sony does some processing on RAW files and saves them as lossy compressed files.  This (lossy compression) has been a continual complaint from A7 series users although I've never seen any obvious degradation of RAW images.

 

Just my approach to EAA...  Works for me!  And it yields better image quality than anything I've obtained using dedicated (purposed) EAA equipment.

 

Just thought I'd add one additional comment.  This approach works equally well for my A7R at ISO's in the 3200-6400 range and gives amazing zoom-in potential (3x the resolution of the A7S) on smaller objects.  I suspect it would be even better with an A7R II...?

 

And another comment.  Monitors can also be adjusted to optimize the Liveview image, just as one would do with a Mallincam or other astro-video equipment.

 

bwa


Edited by bwallan, 29 June 2015 - 02:46 PM.

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#73 Relativist

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Posted 29 June 2015 - 03:54 PM

Thanks much for your contribution bwa. I really enjoy using my a5100 and I'm looking forward to the A7s II as well.

#74 Dom543

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Posted 29 June 2015 - 05:17 PM

Thank you Brian!

It is a lot of useful hands-on information. It is helpful to get facts and working solutions from someone, who actually uses this camera.

Clear Skies!

--Dom



#75 Alex Parker

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Posted 29 June 2015 - 06:03 PM

 

  

First one is the Ring Nebula, a tiny DSO that requires either significant magnification or an equally tiny image sensor.  Jdbastro uses a 10 inch OTA at a slow f/12 focal ratio to obtain sufficient magnification.  The APS-C crop field of view is small at roughly 27 minutes x 18 minutes at 0.6 arcseconds per pixel, maybe a bit oversampled for EAA tastes.  But this fine image scale will allow some more cropping (enlarging) before the image becomes pixilated.  Very pretty, but still tiny and more stars than even I need.  Fortunately, the 1.5 arcminute diameter Ring is bright enough, even at the slow focal ratio, to complete the image in 30 seconds.

 

 

At the risk of sounding horribly pedantic, I can't resist pointing out that the f-ratio per se does not matter.  The f-ratio is not a physical characteristic of an optical system, just the ratio of two physical characteristics: aperture and focal length.  Image scale is completely determined by focal length and sensor dimensions - it is independent of aperture and thus independent of f-ratio.  So an 8" hyperstar SCT and an 80mm f5 refractor will produce exactly the same image scale if used with the same sensor - since they share a 400mm focal length.  The image will "expose" (reach any given level of brightness) roughly 5.2x faster with the SCT (yes I'm accounting for central obstruction) because the SCT has a larger aperture.  Light gathering, and therefore how strongly we can light up a sensor to make an adequate image, is solely a function of aperture, just like for visual astronomy.

 

IMHO, an excellent approach to EAA over subjects of varying scale is to find a scope you can extract a wide variety of focal lengths from with good image quality.  Right now I use my 8" SCT either with or without an 0.5X focal reducer, giving a choice of 1000mm or 2000mm focal length.  Next up is to get a hyperstar lens, which will give me a 400mm option, all with that generous 200mm aperture for good light gathering.  So I can go from teeny (11 x 8 arcmin) scale for e.g. planetary nebulae to decently large (55 x 41 arcmin) all with my trusty Lodestar.  Now that latter (at 400mm) is arguably undersampled at ~4" per pixel, but given the reality of seeing on your average day, probably not terribly.




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