Best DSLR or ILC for Night Sky Imaging?

Started Nov 8, 2017 | Questions
landscaper1
landscaper1 Veteran Member • Posts: 3,562
Best DSLR or ILC for Night Sky Imaging?

Let's suppose someone is interested in doing night sky photography (sky plus landscape foreground) and he/she is not predisposed or otherwise committed to using any specific brand of camera or lenses.

Which make/model of DSLR or mirrorless camera body would provide "the Best" image capture with a minimum of noise?

Which make/model of DSLR or mirrorless camera body would be "2nd Best," and why is it only 2nd Best?

Please submit your recommendations and the reason(s) for them.

-- hide signature --

Landscaper

 landscaper1's gear list:landscaper1's gear list
Sony Cyber-shot DSC-RX10 Canon EOS 5DS R Canon EF 16-35mm F4L IS USM Canon EOS 5D Mark IV Canon EF 50mm F1.8 II +10 more
ANSWER:
This question has not been answered yet.
jammeymc Contributing Member • Posts: 650
Re: Best DSLR or ILC for Night Sky Imaging?

Is there a budget involved or is money not an issue? Noise at base ISO, noise at 1600, noise at 12,800 etc..? I suspect that there will not be a single consensus but my advice for that person would be : start with a base model canon and/or nikon because, if they are asking those questions, it would suit them well to gain experience at the basic level. Any current Canon/Nikon/Sony/Olympus/ ect..dslr is going to provide exceptional results in experienced hands, especially when your talking about widefield/landscapes.

landscaper1
OP landscaper1 Veteran Member • Posts: 3,562
Re: Best DSLR or ILC for Night Sky Imaging?

jammeymc wrote:

Is there a budget involved or is money not an issue? Noise at base ISO, noise at 1600, noise at 12,800 etc..? I suspect that there will not be a single consensus but my advice for that person would be : start with a base model canon and/or nikon because, if they are asking those questions, it would suit them well to gain experience at the basic level. Any current Canon/Nikon/Sony/Olympus/ ect..dslr is going to provide exceptional results in experienced hands, especially when your talking about widefield/landscapes.

Actually, I'm asking for myself.  Though I'm heavily invested in Canon, I'm willing to consider another brand for this limited purpose.  I'm thinking in terms of noise at ISO 1600, 3200, and 6400.

-- hide signature --

Landscaper

 landscaper1's gear list:landscaper1's gear list
Sony Cyber-shot DSC-RX10 Canon EOS 5DS R Canon EF 16-35mm F4L IS USM Canon EOS 5D Mark IV Canon EF 50mm F1.8 II +10 more
rnclark Senior Member • Posts: 3,793
Re: Best DSLR or ILC for Night Sky Imaging?
2

landscaper1 wrote:

Let's suppose someone is interested in doing night sky photography (sky plus landscape foreground) and he/she is not predisposed or otherwise committed to using any specific brand of camera or lenses.

Which make/model of DSLR or mirrorless camera body would provide "the Best" image capture with a minimum of noise?

Which make/model of DSLR or mirrorless camera body would be "2nd Best," and why is it only 2nd Best?

Please submit your recommendations and the reason(s) for them.

As we've seen in past discussions, the lens is far more important, given a relatively modern sensor.  Nightscapes do not push a sensor unless you cripple it with a tiny aperture.  Except for some models that eat stars, any recent camera, paired with a good lens, like 35 mm f/1.4 or24 f/1.4 will do a great job.

To do even better make an array of such cameras with 35 f/1.4 or 50 f/1.4:

1) 1x2, 1x3. 2x2, 2x3, 3x3, etc arrays.

Also, what is the best lens?  All wide angle lenses degrade image quality toward the corners.  That means cropping a full frame sensor more so than a crop camera.   The best lens in this regard is the Canon 35 f/1.4 II, second is probably the Sigma Art 35 f/1.4.

I'm not as impressed with other wide lenses, including available 24 f/1.4 (and shorter loses too much aperture), 50 mm f/1.4, 85 mm f/1.4, then it starts to get better in longer focal lengths.  .... anxiously awaiting start tests of the new Canon 85 f/1.4.

Roger

swimswithtrout Veteran Member • Posts: 3,286
Re: Best DSLR or ILC for Night Sky Imaging?
5

rnclark wrote:

landscaper1 wrote:

Let's suppose someone is interested in doing night sky photography (sky plus landscape foreground) and he/she is not predisposed or otherwise committed to using any specific brand of camera or lenses.

Which make/model of DSLR or mirrorless camera body would provide "the Best" image capture with a minimum of noise?

Which make/model of DSLR or mirrorless camera body would be "2nd Best," and why is it only 2nd Best?

Please submit your recommendations and the reason(s) for them.

As we've seen in past discussions, the lens is far more important, given a relatively modern sensor. Nightscapes do not push a sensor unless you cripple it with a tiny aperture. Except for some models that eat stars, any recent camera, paired with a good lens, like 35 mm f/1.4 or24 f/1.4 will do a great job.

.

Roger

+1,

Though if you can shoot at ISO 12,800-100,000 for 29 sec., with very low noise before the star eater even shows up at 30 sec, using one of your preferred f1.4 lens',there is a very strong point to push the Sony A7s !

Nikon/Pentax buy their chips from Sony and have the same "modern" performance, it's Canon that keeps falling further and further behind.

If you are looking for a "one shot" camera for nightscapes, fixed tripod, than it's impossible to find a better camera than the Sony A7s . It's a "one of a kind" camera optimized for low light photography, and shooting on fixed tripod and it's short exposure limitations will make the "star eater" a moot point.

elgol20
elgol20 Contributing Member • Posts: 653
Re: Best DSLR or ILC for Night Sky Imaging?

rnclark wrote:

..

anxiously awaiting start tests of the new Canon 85 f/1.4.

Roger

I am very pleased with the Sigma Art 135 at 1.8!

 elgol20's gear list:elgol20's gear list
Nikon D800E Nikon D750 Nikon D810A Carl Zeiss Apo Sonnar T* 2/135 Nikkor AF-S 300mm f/4E PF ED VR +4 more
sharkmelley
sharkmelley Senior Member • Posts: 2,173
Sony A7S
3

If you don't mind the large pixels then the Sony A7S is the best out there in terms of sensitivity in low light for two reasons:

1) The low read noise in each (large) pixel means it has the lowest read noise per unit area of sensor than any other camera I know of.

2) The camera is very effective at keeping sensor heat low during continuous use. This gives it the lowest thermal noise per unit area of sensor than any other camera I know of. Take a look at this graph of how dark current (which translates into thermal noise) rises during continuous 5 minute exposures:

These low noise levels give you far greater flexibility when choosing shutter speed and F-ratio.

The big downside with the Sony A7S is the star eater issue but that only happens in bulb mode and you are unlikely to use bulb mode for astro-landscapes. Many people don't notice the star eater issue in any case.

The A7SII uses the same sensor but because the sensor is image stabilised it is much more difficult to conduct the heat away, so the dark current and thermal noise rise faster. Also the star eater kicks in for exposures longer than 4 seconds. The latest firmware (FW 4.0) reduces some of the star eater effects in the green channel but it still kicks in at 4seconds and above.

In addition, if you set it to video mode you can see the Milky Way, aurorae and the brighter galaxies and nebulae in real time - especially if you reduce the frame rate to the slowest setting of 4 frames/sec.

Mark

 sharkmelley's gear list:sharkmelley's gear list
Sony a7S Nikon Z6 +1 more
RustierOne
RustierOne Veteran Member • Posts: 4,314
Re: Best DSLR or ILC for Night Sky Imaging?

swimswithtrout wrote:

rnclark wrote:

landscaper1 wrote:

Let's suppose someone is interested in doing night sky photography (sky plus landscape foreground) and he/she is not predisposed or otherwise committed to using any specific brand of camera or lenses.

Which make/model of DSLR or mirrorless camera body would provide "the Best" image capture with a minimum of noise?

Which make/model of DSLR or mirrorless camera body would be "2nd Best," and why is it only 2nd Best?

Please submit your recommendations and the reason(s) for them.

As we've seen in past discussions, the lens is far more important, given a relatively modern sensor. Nightscapes do not push a sensor unless you cripple it with a tiny aperture. Except for some models that eat stars, any recent camera, paired with a good lens, like 35 mm f/1.4 or24 f/1.4 will do a great job.

.

Roger

+1,

Though if you can shoot at ISO 12,800-100,000 for 29 sec., with very low noise before the star eater even shows up at 30 sec, using one of your preferred f1.4 lens',there is a very strong point to push the Sony A7s !

Nikon/Pentax buy their chips from Sony and have the same "modern" performance, it's Canon that keeps falling further and further behind.

If you are looking for a "one shot" camera for nightscapes, fixed tripod, than it's impossible to find a better camera than the Sony A7s . It's a "one of a kind" camera optimized for low light photography, and shooting on fixed tripod and it's short exposure limitations will make the "star eater" a moot point.

Swims, I have a question regarding the A7S. While I lust after one, with its price and my old NEX cameras not dying, it won't be gotten soon.

My question:

The star eater began kicking in at Bulb = 30 seconds. But a later firmware upgrade lowered that to a shorter exposure. Do you know what the limit is on current new A7S cameras?

Seems like some of the discussion including (Sharkmelley's comments) mentioned holes being punched in the brighter star images. Sounds like your suggestion of keeping exposure less than 30 seconds is the way to go. I sure hope Sony can provide an ON/OFF switch for that effect. They have it enabled because it works best for regular non-astro photographers.

-- hide signature --

Best Regards,
Russ

 RustierOne's gear list:RustierOne's gear list
Sony Alpha NEX-5N Sony Alpha NEX-7 Sigma 19mm F2.8 EX DN Samyang 8mm F2.8 UMC Fisheye Sony E 35mm F1.8 OSS +4 more
sharkmelley
sharkmelley Senior Member • Posts: 2,173
Re: Best DSLR or ILC for Night Sky Imaging?

RustierOne wrote:

My question:

The star eater began kicking in at Bulb = 30 seconds. But a later firmware upgrade lowered that to a shorter exposure. Do you know what the limit is on current new A7S cameras?

The A7S star eater still only happens in bulb mode. So all exposures longer than 30sec are affected (because they have to be done in bulb mode) as well as short exposures done in bulb mode.

The expansion of the star eater issue to all exposures 4sec and longer was done only to the Mark 2 models i.e. the image stabilised models, because of the complaints about increased noise in long exposures compared to the Mark 1 models. The increased noise was probably thermal noise caused by the fact that the sensor has to free to move around and so it can no longer be in contact with heat sinks.

I can't see Sony ever going back to fixed sensors because photographers love image stabilisation, so the Sony A7S will probably remain the best ever Sony camera for low thermal noise.

Mark

 sharkmelley's gear list:sharkmelley's gear list
Sony a7S Nikon Z6 +1 more
RustierOne
RustierOne Veteran Member • Posts: 4,314
Re: Best DSLR or ILC for Night Sky Imaging?

sharkmelley wrote:

RustierOne wrote:

My question:

The star eater began kicking in at Bulb = 30 seconds. But a later firmware upgrade lowered that to a shorter exposure. Do you know what the limit is on current new A7S cameras?

The A7S star eater still only happens in bulb mode. So all exposures longer than 30sec are affected (because they have to be done in bulb mode) as well as short exposures done in bulb mode.

The expansion of the star eater issue to all exposures 4sec and longer was done only to the Mark 2 models i.e. the image stabilised models, because of the complaints about increased noise in long exposures compared to the Mark 1 models. The increased noise was probably thermal noise caused by the fact that the sensor has to free to move around and so it can no longer be in contact with heat sinks.

I can't see Sony ever going back to fixed sensors because photographers love image stabilisation, so the Sony A7S will probably remain the best ever Sony camera for low thermal noise.

Thanks for your informative reply, Mark. In your opinion, when star-eater is not initiated, are the Soy A7S cameras worthwhile for astrophotography. Seems like you reported some manipulation of RAW files in a way you didn't like. I know this has been discussed at length. But my interest in a replacement camera still points toward the A7S.

-- hide signature --

Best Regards,
Russ

 RustierOne's gear list:RustierOne's gear list
Sony Alpha NEX-5N Sony Alpha NEX-7 Sigma 19mm F2.8 EX DN Samyang 8mm F2.8 UMC Fisheye Sony E 35mm F1.8 OSS +4 more
sharkmelley
sharkmelley Senior Member • Posts: 2,173
Re: Best DSLR or ILC for Night Sky Imaging?

RustierOne wrote:

sharkmelley wrote:

RustierOne wrote:

My question:

The star eater began kicking in at Bulb = 30 seconds. But a later firmware upgrade lowered that to a shorter exposure. Do you know what the limit is on current new A7S cameras?

The A7S star eater still only happens in bulb mode. So all exposures longer than 30sec are affected (because they have to be done in bulb mode) as well as short exposures done in bulb mode.

The expansion of the star eater issue to all exposures 4sec and longer was done only to the Mark 2 models i.e. the image stabilised models, because of the complaints about increased noise in long exposures compared to the Mark 1 models. The increased noise was probably thermal noise caused by the fact that the sensor has to free to move around and so it can no longer be in contact with heat sinks.

I can't see Sony ever going back to fixed sensors because photographers love image stabilisation, so the Sony A7S will probably remain the best ever Sony camera for low thermal noise.

Thanks for your informative reply, Mark. In your opinion, when star-eater is not initiated, are the Soy A7S cameras worthwhile for astrophotography. Seems like you reported some manipulation of RAW files in a way you didn't like. I know this has been discussed at length. But my interest in a replacement camera still points toward the A7S.

There is another A7S issue that won't be noticed when doing astro landscapes but will start to become noticeable when performing deep-sky astrophotography where you need to perform vignetting corrections, skyglow subtraction and stretching. The Sony A7S appears to perform a digital scaling of the raw data which leads to regular gaps (or dips) in the histogram and produces coloured concentric rings. It's all explained here:

https://www.dpreview.com/forums/post/59378650

However this can be prevented by shooting with a high enough ISO to make sure the histogram is approximately in the centre of the back of camera display and not over to the left.  This strategy does of course eat into the available dynamic range.

The Sony A7S remains my main deep sky astrophotography camera - I just have to restrict exposures to 30seconds to avoid star eater and expose well to the right to avoid concentric coloured bands.

Mark

 sharkmelley's gear list:sharkmelley's gear list
Sony a7S Nikon Z6 +1 more
elgol20
elgol20 Contributing Member • Posts: 653
Re: Sony A7S

sharkmelley wrote:

If you don't mind the large pixels then the Sony A7S is the best out there in terms of sensitivity in low light for two reasons:

1) The low read noise in each (large) pixel means it has the lowest read noise per unit area of sensor than any other camera I know of.

2) The camera is very effective at keeping sensor heat low during continuous use. This gives it the lowest thermal noise per unit area of sensor than any other camera I know of. Take a look at this graph of how dark current (which translates into thermal noise) rises during continuous 5 minute exposures:

These low noise levels give you far greater flexibility when choosing shutter speed and F-ratio.

The big downside with the Sony A7S is the star eater issue but that only happens in bulb mode and you are unlikely to use bulb mode for astro-landscapes. Many people don't notice the star eater issue in any case.

The A7SII uses the same sensor but because the sensor is image stabilised it is much more difficult to conduct the heat away, so the dark current and thermal noise rise faster. Also the star eater kicks in for exposures longer than 4 seconds. The latest firmware (FW 4.0) reduces some of the star eater effects in the green channel but it still kicks in at 4seconds and above.

In addition, if you set it to video mode you can see the Milky Way, aurorae and the brighter galaxies and nebulae in real time - especially if you reduce the frame rate to the slowest setting of 4 frames/sec.

Mark

Hi Mark, is there a website with this data, different Cameras still?

 elgol20's gear list:elgol20's gear list
Nikon D800E Nikon D750 Nikon D810A Carl Zeiss Apo Sonnar T* 2/135 Nikkor AF-S 300mm f/4E PF ED VR +4 more
sharkmelley
sharkmelley Senior Member • Posts: 2,173
Re: Sony A7S
1

elgol20 wrote:

sharkmelley wrote:

If you don't mind the large pixels then the Sony A7S is the best out there in terms of sensitivity in low light for two reasons:

1) The low read noise in each (large) pixel means it has the lowest read noise per unit area of sensor than any other camera I know of.

2) The camera is very effective at keeping sensor heat low during continuous use. This gives it the lowest thermal noise per unit area of sensor than any other camera I know of. Take a look at this graph of how dark current (which translates into thermal noise) rises during continuous 5 minute exposures:

These low noise levels give you far greater flexibility when choosing shutter speed and F-ratio.

The big downside with the Sony A7S is the star eater issue but that only happens in bulb mode and you are unlikely to use bulb mode for astro-landscapes. Many people don't notice the star eater issue in any case.

The A7SII uses the same sensor but because the sensor is image stabilised it is much more difficult to conduct the heat away, so the dark current and thermal noise rise faster. Also the star eater kicks in for exposures longer than 4 seconds. The latest firmware (FW 4.0) reduces some of the star eater effects in the green channel but it still kicks in at 4seconds and above.

In addition, if you set it to video mode you can see the Milky Way, aurorae and the brighter galaxies and nebulae in real time - especially if you reduce the frame rate to the slowest setting of 4 frames/sec.

Mark

Hi Mark, is there a website with this data, different Cameras still?

Unfortunately not.

Bill Claff's site http://www.photonstophotos.net/ has the widest range of camera testing but has no estimates of thermal noise.

Roger Clark has some thermal noise estimates scattered around his site e.g. http://www.clarkvision.com/reviews/evaluation-canon-7dii/

Brendan Davey has a sensor noise database http://www.brendandaveyphotography.com/more/long-exposure-sensor-testing/ but it is not always obvious how to interpret the results nor whether heat build up may have been a factor during the testing.

I don't of anyone who systematically tests thermal noise increase during a continuous  run of exposures. I've only tested the cameras I own or have borrowed.

Mark

 sharkmelley's gear list:sharkmelley's gear list
Sony a7S Nikon Z6 +1 more
agukha Regular Member • Posts: 211
Re: Sony A7S
1

If you don't want to drag heavy equatorial mounts, but would like to have longer exposures, you can look at the astrotracer function on Pentax cameras ; once calibrated, the sensor is moving to follow the stars.

The Full Frame K1 has the GPS embedded so it's easy to use it anywhere.

On the aps-c cameras, the K3ii has it also, but just now the KP may be a better choice, even if you have to add an external GPS module (O-GPS1) to activate it, as it has very good iso capabilities (like the Nikon D500).

rnclark Senior Member • Posts: 3,793
Re: Best DSLR or ILC for Night Sky Imaging?
2

swimswithtrout wrote:

rnclark wrote:

As we've seen in past discussions, the lens is far more important, given a relatively modern sensor. Nightscapes do not push a sensor unless you cripple it with a tiny aperture. Except for some models that eat stars, any recent camera, paired with a good lens, like 35 mm f/1.4 or24 f/1.4 will do a great job

Roger

+1,

Though if you can shoot at ISO 12,800-100,000 for 29 sec., with very low noise before the star eater even shows up at 30 sec, using one of your preferred f1.4 lens',there is a very strong point to push the Sony A7s !

Nikon/Pentax buy their chips from Sony and have the same "modern" performance, it's Canon that keeps falling further and further behind.

If you are looking for a "one shot" camera for nightscapes, fixed tripod, than it's impossible to find a better camera than the Sony A7s . It's a "one of a kind" camera optimized for low light photography, and shooting on fixed tripod and it's short exposure limitations will make the "star eater" a moot point.

sharkmelley wrote:

If you don't mind the large pixels then the Sony A7S is the best out there in terms of sensitivity in low light

There is another factor being overlooked here. In nightscape photography, we are using relatively fast lenses, and really fast if using f/1.4 lenses. That means collecting a lot of light from the sky very quickly. And modern lenses are quite sharp wide open. If the lens limited resolution one would not see much difference in star star size as sensor pixel pitch decreases. So the signal we get from stars and other small detail in the night sky is a combination of signal from the star, nebula, galaxy, etc plus the signal from the sky.

Large pixels collect more light from the sky reducing contrast with faint stars and other small detail. Thus large pixels in this situation produce lower contrast which becomes a significant loss (of contrast) on small faint objects. Thus noise from the sky will swamp faint signals on small objects, like stars, and other small details.

This effect is shown in Figure 9 here: http://www.clarkvision.com/articles/characteristics-of-best-cameras-and-lenses-for-nightscape-astro-photography/ where pixel sizes of 6.54 microns is on the left, and 4.09 micron pixels is on the right.  (The Sony A7S has 8.4 micron pixels.)

Again, with fast lenses, noise from the sky is far greater than read noise and dark current (unless imaging in a really hot environment, like Phoenix in August).

And you can synthesize any size pixel you want by binning. For example, bin 7D2 4.09 micron pixels 2x2 and get 8.18 micron pixels, or 3x3 and get 12.3 micron pixels.  Watch your image quality degrade.

Optimum pixel size for the sharpness of current fast lenses is 4 to 5 microns.

Roger

sharkmelley
sharkmelley Senior Member • Posts: 2,173
Re: Best DSLR or ILC for Night Sky Imaging?

rnclark wrote:

There is another factor being overlooked here. In nightscape photography, we are using relatively fast lenses, and really fast if using f/1.4 lenses. That means collecting a lot of light from the sky very quickly. And modern lenses are quite sharp wide open. If the lens limited resolution one would not see much difference in star star size as sensor pixel pitch decreases. So the signal we get from stars and other small detail in the night sky is a combination of signal from the star, nebula, galaxy, etc plus the signal from the sky.

Large pixels collect more light from the sky reducing contrast with faint stars and other small detail. Thus large pixels in this situation produce lower contrast which becomes a significant loss (of contrast) on small faint objects. Thus noise from the sky will swamp faint signals on small objects, like stars, and other small details.

This effect is shown in Figure 9 here: http://www.clarkvision.com/articles/characteristics-of-best-cameras-and-lenses-for-nightscape-astro-photography/ where pixel sizes of 6.54 microns is on the left, and 4.09 micron pixels is on the right. (The Sony A7S has 8.4 micron pixels.)

Again, with fast lenses, noise from the sky is far greater than read noise and dark current (unless imaging in a really hot environment, like Phoenix in August).

And you can synthesize any size pixel you want by binning. For example, bin 7D2 4.09 micron pixels 2x2 and get 8.18 micron pixels, or 3x3 and get 12.3 micron pixels. Watch your image quality degrade.

Optimum pixel size for the sharpness of current fast lenses is 4 to 5 microns.

Roger

That's a very interesting point you make about star detectability with large pixels.  I need to go away and think that through ...

Mark

 sharkmelley's gear list:sharkmelley's gear list
Sony a7S Nikon Z6 +1 more
landscaper1
OP landscaper1 Veteran Member • Posts: 3,562
Re: Best DSLR or ILC for Night Sky Imaging?

I want to thank everyone who responded to my initial post.  I've learned a few things (well, maybe more than a few) that I didn't know before.  I posted this query because I really didn't know whether my Canon 5Div was an optimum performer when it came to minimal noise at higher ISOs.

The information about the Sony A7s was news to me and very interesting.  In principal, I can afford to buy an A7s (plus a Metabones adapter so my EF mount lenses will work on the A7s).  However, while my budget may be capable of absorbing that expense, my 40 years of managing other peoples' money still governs my instincts.  That's not to say "economy at any cost," but rather "evaluate whether the additional cost is justified by the performance gains."

That led me to check DPR's review of the A7s and compare noise levels at ISO 6400 for both the A7s and the 5Div.  I'll concede the A7s has the edge, but it seems to me that it's an almost imperceptible edge over the 5Div.  However, the 5Div's edge is, based on Rogers comments, its 5.35 micron pixel size despite being a FF sensor.

On that basis, it seems to me there is really no point in acquiring the Sony A7s no matter how affordable it might be.  Does anyone disagree with that assessment?  If so, please explain.

-- hide signature --

Landscaper

 landscaper1's gear list:landscaper1's gear list
Sony Cyber-shot DSC-RX10 Canon EOS 5DS R Canon EF 16-35mm F4L IS USM Canon EOS 5D Mark IV Canon EF 50mm F1.8 II +10 more
Trollmannx Senior Member • Posts: 5,532
Re: Best DSLR or ILC for Night Sky Imaging?

Just to add confusion:

In my case the Canon 60Da, astromodded 6D and unmodded 7DII is what look at the stars from my location. Use Sony cameras for my ordinary photography.

Use my Canon cameras at ISO1600 (the sweet spot) and typical exposures are 30sek, 1min or 2min depending upon the target and local conditions.

Typically at f/2 (one lens), f/4 (most lenses) and f/5 (astrograph).

My workflow is light plus flats (to reduce vignetting and to kill dust motes), stacking, and some tweaking in AstroArt. Add a final tweak in Photoshop. That is all.

The weather have been extremely lousy here this autumn and I have not had much time to use the Sony A7 in the dark - but have noticed that getting good results from the Sony is much harder than getting good results from my Canon cameras. Might be my workflow.

So in my case I cling to Canon for capturing the night sky. Know my cameras and my workflow - and know what the final result will look like when the exposures are done.

Guess that establishing a good workflow is more important than which camera to use.

Have seen good results from all brands - especially FF cameras, but also APS-C cameras and even smaller formats.

The lens is key - smaller image sensors only limit the field of view, not sensitivity.

rnclark Senior Member • Posts: 3,793
Re: Best DSLR or ILC for Night Sky Imaging?

landscaper1 wrote:

I want to thank everyone who responded to my initial post. I've learned a few things (well, maybe more than a few) that I didn't know before. I posted this query because I really didn't know whether my Canon 5Div was an optimum performer when it came to minimal noise at higher ISOs.

The information about the Sony A7s was news to me and very interesting. In principal, I can afford to buy an A7s (plus a Metabones adapter so my EF mount lenses will work on the A7s). However, while my budget may be capable of absorbing that expense, my 40 years of managing other peoples' money still governs my instincts. That's not to say "economy at any cost," but rather "evaluate whether the additional cost is justified by the performance gains."

That led me to check DPR's review of the A7s and compare noise levels at ISO 6400 for both the A7s and the 5Div. I'll concede the A7s has the edge, but it seems to me that it's an almost imperceptible edge over the 5Div. However, the 5Div's edge is, based on Rogers comments, its 5.35 micron pixel size despite being a FF sensor.

On that basis, it seems to me there is really no point in acquiring the Sony A7s no matter how affordable it might be. Does anyone disagree with that assessment? If so, please explain.

A significant factor you need to consider in comparing cameras on review sites like dpreview is to put the two cameras on equal footing.  Equal ISO is not equal footing.  Equal footing is to put them on the same absolute range in photons.  If the gains between the two cameras are different, then the signal and noise levels between the cameras can't be compared.  For example, does that noise spike you see might in one camera indicate 3 electrons or 15 electrons, translating to 3 or 15 photon noise?  Knowing that is the key to understanding which camera has better sensitivity.

Gains are set by the manufacturer, but to first order scale with pixel area.  So in the case of a Sony A7s with 8.4 micron pixels versus 5D4 with 5.35 micron pixels, ISO 6400 on the 5D4 digitizes the same scale as ISO 6400 * (8.4/5.35)^2 = 15,800, so best would be the closest (e.g. 12,800 on the A7s) in dpreview's comparison except that they change exposure time with iso, so one can't make a real comparison.  So you just have to note that the noise would appear higher in the large pixel camera than in the smaller pixel camera.  Then also remember noise in an astrophoto will not be the noise you see in such review sites, but noise from the sky.

landscaper1
OP landscaper1 Veteran Member • Posts: 3,562
Re: Best DSLR or ILC for Night Sky Imaging?

rnclark wrote:

A significant factor you need to consider in comparing cameras on review sites like dpreview is to put the two cameras on equal footing. Equal ISO is not equal footing. Equal footing is to put them on the same absolute range in photons. If the gains between the two cameras are different, then the signal and noise levels between the cameras can't be compared. For example, does that noise spike you see might in one camera indicate 3 electrons or 15 electrons, translating to 3 or 15 photon noise? Knowing that is the key to understanding which camera has better sensitivity.

Gains are set by the manufacturer, but to first order scale with pixel area. So in the case of a Sony A7s with 8.4 micron pixels versus 5D4 with 5.35 micron pixels, ISO 6400 on the 5D4 digitizes the same scale as ISO 6400 * (8.4/5.35)^2 = 15,800, so best would be the closest (e.g. 12,800 on the A7s) in dpreview's comparison except that they change exposure time with iso, so one can't make a real comparison. So you just have to note that the noise would appear higher in the large pixel camera than in the smaller pixel camera. Then also remember noise in an astrophoto will not be the noise you see in such review sites, but noise from the sky.

Roger, I'm sure you know what you're talking about, but I have my doubts that I do.  So, if you could make it simple for me, "Am I or am I not correct in my judgment that the A7s is only marginally better than the 5Div?"

-- hide signature --

Landscaper

 landscaper1's gear list:landscaper1's gear list
Sony Cyber-shot DSC-RX10 Canon EOS 5DS R Canon EF 16-35mm F4L IS USM Canon EOS 5D Mark IV Canon EF 50mm F1.8 II +10 more
Keyboard shortcuts:
FForum MMy threads