Vorticella (with the new Sony A9)

hkv · Post by **hkv** » Mon Sep 04, 2017 2:12 pm

I have had the opportunity to evaluate the Sony Alpha A9 for microscopy use. The Sony A9 mainly target sports photography which in many aspects are similar to microscopy when chasing a subject to be in focus and keeping it inside the frame. I tried the burst mode with 20fps and captured a moving Vorticella. All but one are single exposures and no stacks. In one occasion, the Vorticella moved through the focus planes and the camera managed to capture it as it glided through the Z-axis. This is the first time I have shot a focus stack where the subject handles the focus adjustments by itself without me moving the objective (!).

I have also included a link to a movie showing the actual capture bursts in action.

https://youtu.be/BGPhCnaCRtY

Here are a selection of the captured images. The last image is a stack of 7 images.

Vorticella by
, on Flickr

Vorticella

micro_pix · Post by **micro_pix** » Mon Sep 04, 2017 5:28 pm

Wow! That's very impressive.

Do you use special lighting or is that the standard lighting for the microscope?

Marek Mis · Post by **Marek Mis** » Tue Sep 05, 2017 12:57 am

Nice and interesting !

Marek

Beatsy · Post by **Beatsy** » Tue Sep 05, 2017 5:15 am

Great set! The A9 is pretty special. Stacking on the scope is a breeze if you can get enough light on the subject. Given the dynamic range, brightfield is usually good enough anyway - so light levels aren't a problem. Just fire the A9 at 20fps on full electronic shutter while cranking the fine focus control. Very similar to video stacking but you get 24mp RAW files to stack instead of lower resolution (medium quality) jpgs.

Jacek · Post by **Jacek** » Tue Sep 05, 2017 8:17 am

Wow !

fpelectronica · Post by **fpelectronica** » Tue Sep 05, 2017 8:37 am

Very very nice. Very good results.

hkv · Post by **hkv** » Tue Sep 05, 2017 11:04 am

Thanks!

Beatsy, yes the advantage of getting raw images is really great as all of the dynamic range is preserved.

pwnell · Post by **pwnell** » Thu Oct 05, 2017 9:19 pm

Really nice. What software are you using to control the A9 if I may ask?

hkv · Post by **hkv** » Fri Oct 06, 2017 2:05 am

micro_pix wrote:Wow! That's very impressive.

Do you use special lighting or is that the standard lighting for the microscope?

micro_pix, sorry, but I missed your question. No, this is no special lightning. Just the normal 100w halogen lamp.

harisA · Post by **harisA** » Fri Oct 06, 2017 2:17 am

Excellent images but I 'm very curious to know how the camera is focusing by itself.Are you using an af telephoto lens as tube lens? A photo of your setup will be very explanatory. Also do u use A9 in crop mode?

hkv · Post by **hkv** » Fri Oct 06, 2017 2:22 am

pwnell wrote:Really nice. What software are you using to control the A9 if I may ask?

Waldo, I use Capture One Pro. I find it very good. Perhaps it has evolved the last two years, but the new version is really good. The learning curve is rather steep, but they have excellent webinars which are free. And it is only $50 for Sony cameras. I have made a customised "Session template" that allow me to automatically tag all images with magnification and all other relevant metadata in the EXIF. For every "Session", I name the session with the current date and the sample ID. Then these gets stored in a directory with the same name, E.g. "Royal_Castle_Pond_2017-10-06". Then all images are named like "Sample_Name_Magnification_Sequence_Number" (Royal_Castle_Pond_60X_0001.ARW). The EXIF then tell all the rest, DarkField, DIC, EPI, Immersion method, etc. The keywords are in a custom keyword library that automatically gets loaded during session creation.

Also, I use an external trigger cable, so I do not use the mouse or keyboard to trigger the camera. Capture One is poor in this respect and there is a lag in the key press. Not so much for single images, but for continuous shooting. With a trigger cable the triggering is instant and stops instantly when the button is released. I have a foot pedal trigger to fire when I chase fast moving subjects. Then I can handle the X-Y movement with the right hand and focus with the left hand and I fire the camera with the foot. Images are automatically downloaded by Capture One Pro and stored in the correct place and following my file naming conventions. The camera has a 240 images buffer, so rapid fire is possible and then Capture One can work and catch up (download) in the background. I only use the capture one interface to set shutter speed and ISO and to click on the right metadata button. Normally I set ISO to "Auto" and only decide on shutter speed depending on the subject. This does not work for darkfield and fluo, when I normally need to force a certain ISO. I have buttons for setting the lightning and contrast method used, the objectives series and magnification. That gets into the EXIF automatically. I must say it is a huge improvement in my workflow compared to the Canon EOS utility I used to rely upon.

hkv · Post by **hkv** » Fri Oct 06, 2017 3:22 am

harisA wrote:Excellent images but I 'm very curious to know how the camera is focusing by itself.Are you using an af telephoto lens as tube lens? A photo of your setup will be very explanatory. Also do u use A9 in crop mode?

Hi, no I need to manually focus using my left hand. Xy with right. Fire with foot. No crop, i use the full full-frame sensor area. I use a 2.5x photo eyepiece before projecting on the sensor.

carlos.uruguay · Post by **carlos.uruguay** » Fri Oct 06, 2017 9:26 am

WOOOOWWW

pwnell · Post by **pwnell** » Fri Oct 06, 2017 9:53 am

hkv wrote:I must say it is a huge improvement in my workflow compared to the Canon EOS utility I used to rely upon.

Thanks for this info. I used to try Capture One Pro too with my A7RII, but the lag, the limited magnification in live view (if I recall correctly) and the horrible support for capturing my comment with the microscope settings in to Exif caused me to abandon ship.

I use DSLR Remote Pro for my Canon system and it is fantastic. Perhaps I'll take another look at C1 Pro, but I sold my Sony gear.

Sumguy01 · Post by **Sumguy01** » Sun Oct 08, 2017 8:15 am

Very nice set.
Thanks for sharing.