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Sony A7s - New Low-Light Camera - Wow!

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#1 jdbastro

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Posted 07 April 2014 - 12:12 AM

I've only had my A7 (full-frame) for a month and it's already about to become obsolete.

The A7s really has me drooling. Could be an awesome low light camera, especially for video (and for me, connection to Gen 3 image intensifiers).

Check out the hype:

A7s Link #1

A7s Link #2

#2 nytecam

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Posted 07 April 2014 - 03:35 AM

Interesting new 4K Sony DSLR camera but it looks as if they were rushed to get the product out for trade fair eg needing [for now] an attached HD harddrive to record the video output!

It's surprising how low the res is for 4K [quad] TV in camera terms [just 50% up from Mallincam Universe] and whilst very impressive in the TV stores on demo there's no broadcast possibility here in UK for the foreseeable future :(

BTW - our local TV store has a big LG OLED curved screen TV on demo for HDTV - sagitta of cylindrical screen ~4" ;)

#3 chasing photons

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Posted 07 April 2014 - 08:43 AM

Maybe the Sony A7s will help curb the pixel war insanity in digital cameras. I don’t see a need for anything greater than 16 megapixels for almost all photographic applications. The full-frame sensor in the Sony is huge and would need special and expensive glass to produce a large, fast image circle. I am hoping that Panasonic and Olympus get on the same page and drop the pixel count for 4/3 sensors. They could go down to 10 megapixels and still have plenty for 4K video (not that I have any use for 4K video in the near future). All I want is a stills camera that will excel in low light and low noise with huge pixels and relatively low pixel count in a small image sensor size with good Wi-Fi remote implementation to a tablet.

One thing is clear; low light, low noise imaging is becoming very popular. And that can only mean good things for near real time astro viewing.

#4 mpgxsvcd

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Posted 07 April 2014 - 09:57 AM

The A7s definitely looks like a beast for low light. If this thing is usable up to ISO 409600 or even ISO 102400 it might make recording real time DSO video possible without the image intensifier.

The m4/3s cameras are good for ISO 12,800 at the most. This camera could be 5 stops more! Basically objects that I am able to see in 8 seconds would appear in ¼ of a second. That also happens to be the longest shutter duration the A7s will do in video.

You really don’t need the 4K resolution for astro stuff though. With a reasonable focal length scope there simply isn’t that kind of definition in the objects we are looking at. What it might be useful for though is using a very short focal length but extremely fast focal ratio scope or even a lens.

This camera might make real time DSO observing possible with standard lenses instead of telescopes. Telephoto F2.8 lenses could be used and still get decent resolution. That could be a gigantic step forward.

I could see a 400mm F2.8 or 800mm F2.8 lens being very useful with this camera. The downside is that those lenses are crazy expensive and I seriously doubt the camera will be $1699 like the GH4 as some rumors have stated.

#5 Chris A

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Posted 07 April 2014 - 12:35 PM

Maurice, I am not surprised with the lower resolution for a 4k sensor because remember this camera is advertising for it's low light video recording. How else are you going to record in low light if Sony does not maintain larger pixels and you can only fit so many pixels within the surface area of the sensor. This is what is needed esp. for what we do DSO observing in near real-time. Yes resolution can be increase by decreasing the pixel size in order to use more pixels within the sensor but the sensitivity will decrease for sure. There is no getting around this!!

Chris

#6 Chris A

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Posted 07 April 2014 - 12:38 PM

Travis, I agree that you really do not need to have 4k sensors for DSO observing unless you plan on printing out your pretty pictures for bill board use LOL.

Chris

#7 ccs_hello

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Posted 07 April 2014 - 07:14 PM

Should be very nice. Each pixel is 8.4um x 8.4um (may be 8.5 x 8.5.)
There are 12 millions of them, as opposed to typical video resolution which is 350K pixels.

The dynamic range and noise control should also be very, very good, or it is not possible to do such extreme digital boost (final few "stops" are pure digital gain.)
This shows low-power CMOS sesnor and SONY Exmor technology is here to stay.

(Well, still patiently waiting for Canon to pump out production quantity 2K pixel 19um x 19um full-frame sized CMOS image sensor. It's awhile since the last PR spin. May be SONY took the hint.)

Clear Skies!

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#8 mpgxsvcd

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Posted 08 April 2014 - 10:46 AM

Travis, I agree that you really do not need to have 4k sensors for DSO observing unless you plan on printing out your pretty pictures for bill board use LOL.

Chris


If you are going to print then don’t do video. That and make sure the focal length of your scope is appropriate for the object you are viewing.

A lot of people think that they will see the ring in great detail with a small refractor if they just have a higher resolution camera. Sensor resolution can only go so far. For instance going from 2(1920x1080 1080p) megapixels to 8 megapixels(3840x2160 4K) is only a 2x gain optically.

Going from a 4 inch scope(Typical Refractor) to an 8 inch scope will give you the same 2x advantage. However, that 8 inch scope(Newtonian) might actually be cheaper than the 4 inch scope. Going from a 2K camera to a 4K camera will almost certainly quadruple your price if not more.

The way to correct problems with not enough resolution is to buy a longer focal length scope. Buying a higher resolution camera can only take you so far.

#9 Chris A

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Posted 08 April 2014 - 03:57 PM

Travis this is what I have been thinking and saying for a couple of years. Many people complain about the resolution of the cameras for example a Mallincam Xtreme. When we are looking at very faint objects such as galaxies and nebulas we need the pixels to be larger then what most camera sensors use. A good way to improve the resolution is to increase the focal length but that means we must also increase our aperture in order to keep the focal ratio low for near real-time observing. Since the pixels must be larger then the typical web cam or cameras made for high resolution solar system viewing, you only have enough real estate to place those larger pixels onto the sensor therefore you are limited more in resolution.

Chris

#10 Moromete

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Posted 10 April 2014 - 02:25 AM

Is it possible to take more than 30s exposures in Bulb with any Sony A7 camera via USB+PC or WiFi+Android phone? If yes, how?

What software for PC or Android enables you these features?

Are Sony A7 cameras capable to take dark frames in the background like Canon 6D does?

If Sony A7s can't do these things, it's useless for astrophotography unfortunately even if it has an excelent sensor (this remains to be seen).

#11 dtripz

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Posted 10 April 2014 - 01:16 PM

http://www.fstopacad...hooting-review/

Theres a video down at the bottom that shows the iso range, looks like image intensifiers will soon get a run for their money.

#12 jdbastro

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Posted 10 April 2014 - 02:07 PM

http://www.fstopacad...hooting-review/

Theres a video down at the bottom that shows the iso range, looks like image intensifiers will soon get a run for their money.


Impressive video.

Imagine coupling an A7s onto the back of a Gen 3 image intensifier and shooting real-time video! That's likely to produce some really nice results.

#13 mpgxsvcd

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Posted 11 April 2014 - 11:35 AM

Is it possible to take more than 30s exposures in Bulb with any Sony A7 camera via USB+PC or WiFi+Android phone? If yes, how?

What software for PC or Android enables you these features?

Are Sony A7 cameras capable to take dark frames in the background like Canon 6D does?

If Sony A7s can't do these things, it's useless for astrophotography unfortunately even if it has an excelent sensor (this remains to be seen).


Yes the camera needs a way to shoot more than 30 seconds. However, I believe it has a bulb mode that can do that. It doesn’t have to have in camera dark frames. You can easily do that by covering the scope or lens separately.

Only Canon cameras are required to use a laptop to control them. There are other ways to control the other cameras that make them suitable for AP.

#14 jdbastro

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Posted 11 April 2014 - 02:50 PM

Is it possible to take more than 30s exposures in Bulb with any Sony A7 camera via USB+PC or WiFi+Android phone? If yes, how?

What software for PC or Android enables you these features?

Are Sony A7 cameras capable to take dark frames in the background like Canon 6D does?

If Sony A7s can't do these things, it's useless for astrophotography unfortunately even if it has an excelent sensor (this remains to be seen).


Here's my answer from a recent PM:

====================================================
So far I've determined the following with my A7.

1) Yes, if you put the camera in Bulb mode, you can take exposures longer than 30 sec. I just tried a 64 sec exposure and it worked, AND, it was followed by about 64 sec of processing, which implies that this was noise reduction, I think.

2) The A7 does not have an internal intervalometer. There is a smartphone / iPad app available but BULB is not available with this app which is called 'Smart Remote Control'. I don't know if there is some other s/w for control.

3) I think that the camera has internal noise reduction for longer exposures based on my 64 sec BULB attempt.
========================================================

Additionally, one can shoot with BULB via a wired remote control. The control has a lock to hold the exposure easily for as long as desired. I have this remote and it works great.

#15 PEterW

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Posted 12 April 2014 - 09:56 AM

Be interesting to see live speed Milky Way shots, most time lapse Milky Way vids are using reasonable exposures for each frame. With high quantum efficiency and noise reduction it ought to nail intensifiers, we will have to see:... Different spectral bandwidth.
Always good to see new toys emerging.

Peter

#16 tim53

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Posted 12 April 2014 - 03:28 PM

This just might be the full frame mirrorless camera I've been waiting for...

-Tim.

#17 Moromete

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Posted 13 April 2014 - 06:04 AM

Don't get too excited yet.

According to this link http://www.eoshd.com...ng-shutter-test it seems Sony is not aiming for a "decent" price (up to 2000$) and a 4000$ price appeared on the Sony UK site shortly.

That's a crazy price. It's not worth more $ than A7R.

#18 chasing photons

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Posted 13 April 2014 - 10:45 AM

I have also seen rumors placing the A7s camera body around $3500. I guess it's the price you pay for a 'specialty' camera (fewer and bigger pixels and 4K video).

I think the major astro imaging camera companies and the major optical tube manufacturers need to pool together and come up with a standard for a latest technology, high QE, low noise, 2-4 megapixel sensor around 4/3" size or less (big pixels) in a cooled body that will work well with fast < f5 optical tubes with the specific intention of near real time viewing. I think the potential market would be huge once amateur astronomers see what fantastic views could be had with little work in relatively short time (under a few minutes) assuming automatic aligning and stacking of shorter exposures on the fly. Shorter integration times (less than 60 seconds) would eliminate the need for guiding equipment and only require a decent tracking mount in equatorial or alt-az mode. We are still talking $4K - $5K for a good, complete system of optical tube, tracking mount, camera, integrated software that runs everything and a laptop/tablet. At that price point, I still think the market would be huge. By huge, I mean larger than the astro imaging market. This near real time viewing market would be a NEW market in between the visual eyepiece and the imaging markets. Lots of imagers would drop down to this new market and lots of eyepiece users would climb up and throw away their eyepieces.

#19 Moromete

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Posted 13 April 2014 - 11:00 AM

If someone accepts to pay $3-4000 for a Sony A7S maybe it's better to wait for a Nikon with the same sensor and a better all around dslr. Just a thought.

Considering the rumored prices till now it seems Sony hunts for a big and unjustified price premium for A7S. I'm not sure that will be a wise management decision.

Besides the exciting sensor the A7S as a whole has many minuses like lack of phase detection AF, inability to record 4k video on memory cards, lack of flash, no touchscreen, a poor PC app lacking LiveView, tiny battery (especially for video recording->stupid decision), probably still a very loud shutter, etc.

#20 tim53

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Posted 13 April 2014 - 11:52 AM

Well, if it really is over $3000, I'll probably look at other options. An astrocamera capable of binning comes to mind.

Come to think of it, why don't DSLRs allow binning? Astro IIDC can bin color camera pixels (firewire and USB machine vision).

-Tim.

#21 nytecam

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Posted 13 April 2014 - 01:10 PM

Checked out Sony and Jessops stores in Horsham Sussex today and 7Sbody £2500 and 7R body £1750 but no news of when :-) Talk of an astro market for these camera is optimistic - this market is minute in photo sales much as it is in the astroCCD market:-)
ps: returned to the Currys TV megastore now with two curved 4K TVs on display in foyer by LG and Samsung :grin:

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#22 nytecam

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Posted 13 April 2014 - 01:12 PM

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#23 Moromete

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Posted 13 April 2014 - 02:07 PM

£2500 for the A7S?! :tonofbricks:

That's intangible for me. That's also almost twice more expensive than a Canon 6D.

Nytecam, I hope your price is very exagerated! :cool:

#24 tim53

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Posted 13 April 2014 - 02:08 PM

Sadly, it's probably not...

The Canon 6D is looking more attractive all the time.

-Tim.

#25 Relativist

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Posted 14 April 2014 - 12:27 AM

So, is there a chance that the sensor will be available in a dedicated astro camera?






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