Jump to content


Photo

New Sony full-frame...

  • Please log in to reply
44 replies to this topic

#26 Jon Rista

Jon Rista

    Vanguard

  • -----
  • Posts: 2372
  • Joined: 10 Jan 2014
  • Loc: Colorado

Posted 13 April 2014 - 01:47 PM

Moromete, Sony applies a lot of these things to their RAW images as well. Same goes for Nikon. Black-point-clipping definitely occurs in hardware, and that makes use of "standard" AP noise reduction routines difficult. Even Canon does a little bit to their RAW files when they save them, but at least they use a bias offset rather than black point clipping. When it comes to DSLRs, it's pretty much impossible to get away from in-camera frame manipulation...however Canon seems to be the least of the offenders.

#27 james7ca

james7ca

    Viking 1

  • -----
  • Posts: 566
  • Joined: 21 May 2011
  • Loc: San Diego, CA

Posted 14 April 2014 - 02:28 AM

It may be worth remembering that just about any digital camera will support liveview over their HDMI connection. So, even if the Sony doesn't allow liveview over USB it can be done at full 1080p quality and frame rate over the HDMI connection.

This is exactly how I do scope alignment, focus, and image review with my Sony NEX cameras. I use a battery-powered, 7" HD field monitor that gives me 30fps video on a large display that also has hardware zoom capabilities. It even works without a computer, but I suppose if I wanted the display on the computer I could just add a video capture device to the PC.

#28 Moromete

Moromete

    Viking 1

  • *****
  • Posts: 665
  • Joined: 15 Feb 2012
  • Loc: Romania

Posted 14 April 2014 - 04:03 AM

LiveView over HDMI has no practical use for me because I control all my equipment over a single USB cable connected to a laptop inside the house. I can also control my mount only over Bluetooth.

I'm very curious to see how well will the A7S perform at ISO 25.600 considering the A7/A7R have much more chroma noise than Canon 6D and even Nikon D610 at ISO 12.800. In other words if Canon 6D could be usable at ISO 12.800, Sony A7/A7R are completly unsable over ISO 6400 if you compare them in RAW on DPReview.com in the low light scene.

According to DXOMark camera comparison tool, Sony A7/A7R have lower DR than Canon 6D at ISO 3200/6400.

I suppose the maximum usable ISO with Sony A7S will 25.600 for astrophotography and probably will have the noise Canon 6D has at ISO 6400.

Now considering the already crazy rumored prices I'm affraid the A7S it's not worth the big price premium for astrophotography especially when comparing it to Canon 6D. What do you think?

#29 Jon Rista

Jon Rista

    Vanguard

  • -----
  • Posts: 2372
  • Joined: 10 Jan 2014
  • Loc: Colorado

Posted 14 April 2014 - 03:08 PM

@Moromete: I am not so sure your correct about the amount of noise at ISO 25600. That is a native ISO setting, and the A7s has MUCH larger pixels than the 6D (9.7µm vs. 6.4µm). The larger pixels of the A7s should give it a dynamic range advantage, so less noise at any given native ISO. This is in contrast to the A7/A7r, both of which have smaller pixels than the 6D, so having more noise at high ISO is expected.

The real question is, why would anyone use ISO 25k anyway? Astrophotography is all about getting signal strength. You can stack to your hearts content, beyond a certain point it won't do anything to improve the signal strength itself, it will only reduce noise. The only way to capture dim dust detail that isn't visible in a short exposure is to expose for longer. ISO 25k on the A7r is likely to have somewhere between 400-500e- charge at saturation. ISO 400, on the other hand, would likely have closer to 30,000e- at saturation. I'd MUCH rather use ISO 400 than ISO 25k, simply because with only 400-500 electrons at saturation, you'll clip your white point in only a minute or two.

With say 30ke- at ISO 400, you could expose for 10 minutes easily and avoid clipping, and have a much stronger signal than any other DSLR currently on the market (except maybe the 1D X).

I don't see the value of ultra high ISO settings for astrophotography. They are limited by physics...it doesn't really matter how good your camera is, unless it's got ultra monstrous pixels (much, much larger than even the 10µm of the A7s), the saturation point at ISOs above around 3200 to 6400 are just never going to be useful...your intrinsically limiting your saturation point, which means clipped stars and galactic core occur with shorter and shorter exposures.

#30 Moromete

Moromete

    Viking 1

  • *****
  • Posts: 665
  • Joined: 15 Feb 2012
  • Loc: Romania

Posted 14 April 2014 - 11:51 PM

Guys, have a brake for a moment and look at these high ISO shots taken with Sony A7S http://www.photograp...iso-comparison/ .

Does a Canon 6D user ( or anyone else) think that ISO12800-25600 of A7S is considerably cleaner than same ISOs of 6D?

#31 Jon Rista

Jon Rista

    Vanguard

  • -----
  • Posts: 2372
  • Joined: 10 Jan 2014
  • Loc: Colorado

Posted 15 April 2014 - 03:12 AM

I'd like to see some direct comparisons between the A7s and 6D, with a black swatch and an 18% gray swatch. It's really tough to compare noise when you have complex information in the scene, so plain swatches help. It is still useful to take samples of a complex but standardized scene anyway, though, as it gives you a better idea of how the noise actually affects IQ. Still, you need some directly comparable shots. It's really, really tough to say, objectively, how the noise of one camera compares to that of another when you only have disparate samples to compare.

#32 SunBlack

SunBlack

    Viking 1

  • -----
  • Posts: 890
  • Joined: 05 May 2011
  • Loc: Rome (IT)

Posted 15 April 2014 - 06:14 AM

I'd like to see some direct comparisons between the A7s and 6D

Me too. A dark frames comparisons would be even better.

#33 Moromete

Moromete

    Viking 1

  • *****
  • Posts: 665
  • Joined: 15 Feb 2012
  • Loc: Romania

Posted 15 April 2014 - 09:31 AM

Why does the A7S have a 12Mpx sensor if it uses only 8-9Mpx for 4K video?

Going down to 8-9Mpx they could have made the pixels bigger.

#34 chasing photons

chasing photons

    Vostok 1

  • -----
  • Posts: 130
  • Joined: 19 Mar 2013
  • Loc: Minnesota

Posted 15 April 2014 - 10:10 AM

Why does the A7S have a 12Mpx sensor if it uses only 8-9Mpx for 4K video?


For the same reason the Panasonic GH4 still has 16 megapixels and shoots 4K video. These are also still cameras and the vast majority of photographers want as many pixels, and consequently, the highest resolution they can get. Low light performance is not the highest priority for the majority of photographers. But I agree that these pixel wars are ridiculous and, for most cases, 10 megapixels would be plenty.

#35 Jon Rista

Jon Rista

    Vanguard

  • -----
  • Posts: 2372
  • Joined: 10 Jan 2014
  • Loc: Colorado

Posted 15 April 2014 - 10:42 AM

Why does the A7S have a 12Mpx sensor if it uses only 8-9Mpx for 4K video?

Going down to 8-9Mpx they could have made the pixels bigger.


A video frame is 16:9 ratio, where as the sensor is 3:2 ratio. To get a 16:9 ratio image out of a 3:2 sensor, you have to crop the top and bottom. Hence the reason you lose almost 4mp.

#36 Moromete

Moromete

    Viking 1

  • *****
  • Posts: 665
  • Joined: 15 Feb 2012
  • Loc: Romania

Posted 15 April 2014 - 12:50 PM

Clear now. Thanks.

#37 Moromete

Moromete

    Viking 1

  • *****
  • Posts: 665
  • Joined: 15 Feb 2012
  • Loc: Romania

Posted 16 April 2014 - 03:28 AM

Here is a very nice comparison of Canon 6D, Sony A7/A7R and Nikon DF for astrophotography purposes: http://www.davidking...ightweight-c... .


Talking about noise at ISO6400 with NR turned On, all sensors seem to perform quite the same. Starting with ISO12800 things will change quite a bit in favour of the new Sony A7S I suppose.

It seems the Sony A7/A7R is hard to focus in LiveView on stars, unlike Canon. Probably the same dificulty, or worse, will be present with the new Sony A7S. Probably due to its 12Mpx sensor the A7S will be even harder to focus precisesly on stars (or maybe not?!). A Bahtinov mask will be a mus with Sony for focusing but this is not working with normal dslr lenses.

Also it seems the mirrorless design of A7/A7R is not usefull at all for astrophotography. Still the pentaprism of Canon 6D and Nikon DF is the way to go at night. Again, this problem will be encountered with A7S, too.

On the whole as a camera, besides the possible wonderfull sensor,I'm not sure how usefull will be the new Sony A7S for astro work and this dissapoints me besides the exagerated rumored prices.

What do you think about this flaws of Sony A7S?

#38 SunBlack

SunBlack

    Viking 1

  • -----
  • Posts: 890
  • Joined: 05 May 2011
  • Loc: Rome (IT)

Posted 16 April 2014 - 04:26 PM

Here is a very nice comparison of Canon 6D, Sony A7/A7R and Nikon DF for astrophotography purposes: http://www.davidking...ightweight-c... .

Nice.

#39 Jon Rista

Jon Rista

    Vanguard

  • -----
  • Posts: 2372
  • Joined: 10 Jan 2014
  • Loc: Colorado

Posted 16 April 2014 - 07:19 PM

Here is a very nice comparison of Canon 6D, Sony A7/A7R and Nikon DF for astrophotography purposes: http://www.davidking...ightweight-c... .


Talking about noise at ISO6400 with NR turned On, all sensors seem to perform quite the same. Starting with ISO12800 things will change quite a bit in favour of the new Sony A7S I suppose.

It seems the Sony A7/A7R is hard to focus in LiveView on stars, unlike Canon. Probably the same dificulty, or worse, will be present with the new Sony A7S. Probably due to its 12Mpx sensor the A7S will be even harder to focus precisesly on stars (or maybe not?!). A Bahtinov mask will be a mus with Sony for focusing but this is not working with normal dslr lenses.

Also it seems the mirrorless design of A7/A7R is not usefull at all for astrophotography. Still the pentaprism of Canon 6D and Nikon DF is the way to go at night. Again, this problem will be encountered with A7S, too.

On the whole as a camera, besides the possible wonderfull sensor,I'm not sure how usefull will be the new Sony A7S for astro work and this dissapoints me besides the exagerated rumored prices.

What do you think about this flaws of Sony A7S?


I think Sony is using a shotgun approach to gaining market share. Throw out as many sensor designs and camera models as possible, see which ones stick, and if/when any do, then figure out how to improve them (maybe).

I'm also honestly not sure that Sony really cares all that much about their cameras. The big business is really in their sensor fabrication business. Sony sells sensors to EVERYONE now, and they have a huge variety of them applicable in multiple market sectors.

I like the Sony Exmor sensor design for stills photography, I think it is amazing. I'm really not a fan of Sony cameras, though. They have lackluster firmware, some incomplete features, and their ergonomics are lacking.

#40 Fogboundturtle

Fogboundturtle

    Viking 1

  • -----
  • Posts: 716
  • Joined: 20 May 2009
  • Loc: Burnaby, BC

Posted 17 April 2014 - 03:32 PM

What makes the A7/A7r difficult to use for AP is that you cannot use remote live view on PC. Only on smartphone and table right now. Plus, It is noisier at ISO 1600 than my 5D3.

I think Jon nailed it. They are landscape still camera (A7/A7r) and at very low ISO they perform better than Canon. I am sure the A7s will be use mostly by videographer and not astrophographer.

#41 Hikari

Hikari

    Viking 1

  • *****
  • Posts: 940
  • Joined: 05 Jan 2011
  • Loc: Maine, USA

Posted 17 April 2014 - 05:07 PM

Sony is one of the most innovative camera companies today. Making a series of compact 35mm sensor cameras for photographers with different needs is probably good business sense for trying to create a whole new line. Considering they are also really well-made cameras surely must indicate they care about cameras. The ergonomics of the Sony cameras are fine--personal preference is irrelevant.

Canon is the one really struggling with their sensor technology. On DxO Mark scores, they don't have a camera in the top 25, that includes APS cameras. Above them is Sony, Nikon, Pentax, Phase One, and Leica.

#42 Jon Rista

Jon Rista

    Vanguard

  • -----
  • Posts: 2372
  • Joined: 10 Jan 2014
  • Loc: Colorado

Posted 17 April 2014 - 05:26 PM

You gotta take DXO Mark scores with a very healthy dose of salt. Their scores attempt to reduce the very complex notion of "Image Quality" down to a single number. There are other factors that affect IQ that DXO completely ignores (since all they do is test just the sensor). If Canon "cameras" were as bad as DXO indicates, they wouldn't have the strong sales and following they do have, and cameras like the D800 would have taken over. All you have to do is look at photos taken with the 5D III and 1D X to see that DXO's scores are missing something.

#43 mpgxsvcd

mpgxsvcd

    Surveyor 1

  • -----
  • Posts: 1951
  • Joined: 21 Dec 2011
  • Loc: Raleigh, North Carolina

Posted 22 April 2014 - 01:11 PM

If Canon "cameras" were as bad as DXO indicates, they wouldn't have the strong sales and following they do have


There are a whole lot of people out there that have no idea what makes one camera better than another one. They bought a Canon A-PSC camera simply because Andre Agassi made it look cool back in the day. Now they don't want to switch and buy their lenses again.

Canon Full frame cameras are not bad cameras. Canon A-PSC cameras lag WAY behind everything else made today but they still sell well because of Canon marketing and their reputation that was based on their full frame models.

#44 nine44

nine44

    Ranger 4

  • *****
  • Posts: 314
  • Joined: 19 Jan 2013

Posted 22 April 2014 - 02:28 PM

Canon A-PSC cameras lag WAY behind everything else made today but they still sell well because of Canon marketing and their reputation that was based on their full frame models.


I get that the herd instinct and good marketing does lead a lot of sheeple toward established brands. However, I think it is hard to argue with the sheer volume of fine astrophotography that has been taken using Canon APS-C cameras. I don't think all of the talented APers on this site using Canon APS cameras are simply deluded by good marketing and brand recognition.

#45 tazer

tazer

    Messenger

  • -----
  • Posts: 483
  • Joined: 22 Dec 2011
  • Loc: Central North Carolina

Posted 22 April 2014 - 03:21 PM

I get that the herd instinct and good marketing does lead a lot of sheeple toward established brands. However, I think it is hard to argue with the sheer volume of fine astrophotography that has been taken using Canon APS-C cameras. I don't think all of the talented APers on this site using Canon APS cameras are simply deluded by good marketing and brand recognition.


Well, the other aspect is Canon's internal CPU's and SDK's. Just look at what BackyardEOS is capable of. Sony seems to be behind the curve in that regard.

The other big problem I have with Sony, and maybe my expectations are unrealistic, is their ever-changing product line. My camera, the NEX-5, was released in May of 2010 and discontinued just 15 months later. The final firmware, essentially, came out in June of 2011 and the product has since been abandoned. I understand updating the product line with newer models, but refusing to update the firmware to provide enhancements that other similar models of Sony cameras are getting is just wrong.

My impression of Sony is, buy their top-tier product of a given product line or they'll abandon whatever it is you purchased in hopes that you'll spend the money on an upgrade. Here it is 4 years later and Sony's right, I'm going to pony up for a new camera soon. It will not, however, be a Sony.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics