Sony A9, full frame RAW "video" stacking...

Beatsy · Post by **Beatsy** » Wed Jul 19, 2017 3:01 pm

OK, not really video, but a quick test of something I've been meaning to try for a while. The Sony A9 can capture 240 full frame, compressed RAW images at 20 fps before the buffer fills and frame rate slows. This uses a fully electronic shutter too (so no vibrations). Here's some diatoms - a stack of 120 images taken by racking through focus while shooting at the aforementioned 20 fps.

Not bad! Much higher resolution than 4k video and a larger field of view (frame height drops for video aspect ratio). It's 12 bit RAW rather than mid quality, 8-bit jpg too (using continuous drive drops dynamic range from 14-bit as used for single-shot stills - but it doesn't cause any noticeable image degradation).

I included a 50% crop for pixel peepers but it's into diffraction-limited territory as it was only shot with a 40/0.9 water immersion objective. The field of view of the first image is 200 microns and settings for each frame were 1/500th, ISO 100, custom white balance.

Another tool in the box.

zzffnn · Post by **zzffnn** » Wed Jul 19, 2017 3:35 pm

Very nice and helpful, thank you for sharing! I did not know A9 can do that.

240 frames per stack at 20 fps should be more than enough for most of my live protists.

I wonder if a micro four thirds camera, such as Olympus Pen F, can do the same at such high resolution? If so, that will be my next camera purchase. I already have a few m4/3 lenses and don't want to change sensor or lens (afocal) mounts.

Choronzon · Post by **Choronzon** » Wed Jul 19, 2017 4:14 pm

Hi Beatsy,
That looks pretty impressive. Do you own this camera, and if so, what , if any, other than the price, do you see as a drawback? Im holding out on full frame and still limping along with a cheapo Canon APS. This Sony is as expensive as a dedicated Nikon FF microscope camera ( with my employee discount) and as a bonus can be used with any lens or microscope. Im leaning towards Sony or Canon for full frame digital
Regards, Steve

Beatsy · Post by **Beatsy** » Wed Jul 19, 2017 5:04 pm

Choronzon wrote:Hi Beatsy,
That looks pretty impressive. Do you own this camera, and if so, what , if any, other than the price, do you see as a drawback? Im holding out on full frame and still limping along with a cheapo Canon APS. This Sony is as expensive as a dedicated Nikon FF microscope camera ( with my employee discount) and as a bonus can be used with any lens or microscope. Im leaning towards Sony or Canon for full frame digital
Regards, Steve

Thanks.

After a decade shooting Canon cameras, I switched to Sony mirrorless last year. I started with A7rii, soon added another (backup) and recently added the A9 too. Never looked back.

I use my cameras for a lot of "normal" photography (including weddings, events and portraiture) as well as for macro and micro. Given this, I find the Sony's are just amazingly versatile with the short flange distance making it trivial to adapt just about any lens (or microscope) you can imagine.

That aside, image quality, low light performance and in-body image stabilisation (IBIS) are superb - the best I've ever experienced. I still have my Canon bodies, but haven't touched them since that first A7rii arrived. I really should get rid. So needless to say, I would strongly recommend Sony over Canon. A9 if you want speed, great AF (693 phase detect points over 93% of the sensor!!!) and "only" 24mpix. A7rii if you want high resolution and a stop of extra dynamic range. I kind of want/need both, depending on what I'm doing, hence not trading in my A7rii's when I got the A9.

For photomicrography specifically, I prefer the A9. I know others may disagree on this point, but I find that 24 mpix (A9) is on the sweet spot with 42 mpix (A7rii) being far too much. More often than not, 42mpix way outresolves the objectives and the image files really slug my PC when processing.

In summary, if it were my money, I'd not even consider a dedicated FF microscope camera (unless doing super-sensitive fluorescence work). It would be an A9 - bringing all the "bonus benefits" you mention for use off the microscope. If budget were tighter and raw speed didn't matter, then A7rii would be OK too (just downsize microscope images before pushing into the processing pipeline).

That's all just IMO of course and switching systems is more than just buying a different body. Support may be an issue for you (Canon is still better - but Sony are improving). And legacy glass is a consideration (it can be adapted to Sony but native generally works far better). Etc...

Hope that helps.

Beatsy · Post by **Beatsy** » Wed Jul 19, 2017 5:21 pm

zzffnn wrote:Very nice and helpful, thank you for sharing! I did not know A9 can do that.

240 frames per stack at 20 fps should be more than enough for most of my live protists.

I wonder if a micro four thirds camera, such as Olympus Pen F, can do the same at such high resolution? If so, that will be my next camera purchase. I already have a few m4/3 lenses and don't want to change sensor or lens (afocal) mounts.

Pen F can do 10fps RAW with a buffer of 39 frames. Faster (20fps) and more for jpg.

zzffnn · Post by **zzffnn** » Wed Jul 19, 2017 5:38 pm

Thank you very much, Beatsy. Hmmm. 39 frames buffer vs 240 frames buffer.......that is quite a lot of difference. Though 39 frames is likely about good enough for my soft bodied protists.

Edit: Panasonic GH4 seems to shoot at 12 fps RAW and 40 RAW frames max as well. So Sony A9 is much faster there. A7 II seems to shoot at 5 fps only (maybe resolution needs to be reduced to get fast burst rate, in that case)?

Choronzon · Post by **Choronzon** » Thu Jul 20, 2017 11:44 am

Beatsy, thank you for the insight. I agree that a microscope specific camera is too limiting for the price. Sony has kind of progressively upped their imaging game, as far as I have seen. I love the Canon software, but I think going forward, competing with a giant like Sony, who obviously has the resources to research and develop sensors like few other companies can, will be an increasingly serious problem for other camera makers. The price of the A9 is high, but it would seem to be the perfect dual purpose microscope camera. And you can use Leica M lenses. Software can improve, the basic hardware can only be solved with more money spent.

concon · Post by **concon** » Fri Jul 21, 2017 7:16 am

Super appreciate this post. I've been a Sony fan for a year now (only been shooting for about a year and started with them), and was ecstatic when I heard what the a9 was capable of doing- innovation and pushing the bounds! I definitely had seen a few examples of stacking via 4k video, but was beyond curious what their latest camera could squeeze out. I'm crossing my fingers that this same technology will be in their a7riii- my money will be flying at them.