Focus stacking

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Glot
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Joined: Thu Oct 17, 2019 7:23 am

Focus stacking

#1 Post by Glot » Fri Nov 22, 2019 4:00 am

Brand new to this. Open to feedback. A LOT to learn still.
Epidote. FOV 5mm across.
5mp cam.
Picolay
Edited post processing. W10 VIEWER.
Light. LED 2700K (because it's what I had)
Comment: Found Picolay very easy and great for a beginner to try out (me).
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75RR
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Location: Estepona, Spain

Re: Focus stacking

#2 Post by 75RR » Fri Nov 22, 2019 4:59 am

Great start. You might try diffusing the light source - cut in half ping-pong balls are a popular method.
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

MicroBob
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Re: Focus stacking

#3 Post by MicroBob » Fri Nov 22, 2019 6:57 am

Hi,
that looks very promising!
I use Picolay too. While I don't have experience withother stacking software I'm happy with the performance.
You might try an increased number of steps to improve image quality further. White single use plastic cups without bottom are a good diffuser too.

Bob

Glot
Posts: 76
Joined: Thu Oct 17, 2019 7:23 am

Re: Focus stacking

#4 Post by Glot » Fri Nov 22, 2019 7:46 am

Yes, lighting was on my mind too. Thanks for the suggestions. So many variables to play with.
One issue I have is the image creeps sideways on the monitor. It has to be a mis alignment of a prism or what ever they use to split the image. I use the align image option but that could also reduce results a bit. I a, also thinking for this type of work, multiple light sources would help from different angles.

MicroBob
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Re: Focus stacking

#5 Post by MicroBob » Fri Nov 22, 2019 8:22 am

Did you take the pictures with a stereo microscope?

Glot
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Re: Focus stacking

#6 Post by Glot » Fri Nov 22, 2019 8:49 pm

Yes Bob and I am finding the focus too coarse. Going to try lower magnification, process then enlarge and crop. Also work on the lighting. Thanks to everyone in here I am learning so much. The image is stable through the eye pieces but creeps in the camera as I focus

MichaelG.
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Re: Focus stacking

#7 Post by MichaelG. » Fri Nov 22, 2019 10:01 pm

Glot wrote:
Fri Nov 22, 2019 7:46 am
... One issue I have is the image creeps sideways on the monitor. It has to be a mis alignment of a prism or what ever they use to split the image. ...
I think that is probably what Bob had in mind when he asked whether you were using a stereo microscope.
If the subject is flat on the stage then stacks taken down one tube will inevitably show some creep.

MichaelG.
.

Edit: Just found this discussion from 2015
viewtopic.php?t=1628
Too many 'projects'

MicroBob
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Re: Focus stacking

#8 Post by MicroBob » Sat Nov 23, 2019 8:13 am

Stereo microscopes generally only give a so-so quality. They barely resolve enough detail for the eye and can't offer what a sensor can resolve. In the places where your imahe is sharp you probably have already reached what is possible.
At least Greenough stereo microscopes have an image shift when focussing. I don't have a CMO stereo microscope so I can't comment on this.
Picolay offer a function "align images". So it may be able to cope whith this automatically. Perhaps the stepping has to be fine to make this function work.

Bob

MichaelG.
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Re: Focus stacking

#9 Post by MichaelG. » Sat Nov 23, 2019 9:39 am

Glot wrote:
Fri Nov 22, 2019 8:49 pm
... The image is stable through the eye pieces but creeps in the camera as I focus
You posted that reply whilst I was composing mine, so [sorry] I missed it.
The apparent stability of the visual image is a nice demonstration of the fact that ‘seeing’ is not a purely optical function, but a complex system involving the brain.
If you try photographing via the other tube, you should find that the stack creeps in the opposite direction.
[unless, of course, your ‘scope is trinocular ... in which case the manufacturer has chosen]

MichaelG.
.

What make/model of stereo are you using; and how is the camera attached ?
.
Edit: I have just looked back to your very first post on the forum:
Just bought a szm zoomable stereo microscope with trinoccular port. Just for home hobby use. I want to fit a usb compatible camera.
... so you can ignore my suggestion about swapping sides.
Too many 'projects'

Glot
Posts: 76
Joined: Thu Oct 17, 2019 7:23 am

Re: Focus stacking

#10 Post by Glot » Sat Nov 23, 2019 12:24 pm

Still interesting info. It makes perfect sense. As you say, the camera port is only through one objective so will creep. I'm learning.
Last edited by Glot on Sun Nov 24, 2019 1:19 am, edited 1 time in total.

Glot
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Re: Focus stacking

#11 Post by Glot » Sat Nov 23, 2019 12:27 pm

Ideally, I would love three microscopes. This stereo, a petroscope and a biological with darkfield capabilities, camera and long distance objective. However, I have other priorities at the moment such as food etc. So far, I have been happy with this unit. Would like finer focus adjustment and rack and pinion height adjustment.

Glot
Posts: 76
Joined: Thu Oct 17, 2019 7:23 am

Re: Focus stacking

#12 Post by Glot » Sun Nov 24, 2019 7:39 am

Fun learning. Finer steps needed.Colour correction is an issue still. I think a cooler coloured light will help. Might also have to move to better editing software. Using W10 which is okay but limited.
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MicroBob
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Re: Focus stacking

#13 Post by MicroBob » Sun Nov 24, 2019 9:16 am

Probably you could use even finer steps to further improve quality. Not that easy with a typical stereo microscope coarse focus.
I picked a white point in GIMP - here is the result:

Bob
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MichaelG.
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Re: Focus stacking

#14 Post by MichaelG. » Sun Nov 24, 2019 10:48 am

Glot wrote:
Sun Nov 24, 2019 7:39 am
Fun learning. Finer steps needed.
Keep up the good work, and keep enjoying it

One suggestion ... Instead of modifying/replacing the main focus, consider using a fine-focus stage for the specimen.

MichaelG.
Too many 'projects'

MicroBob
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Re: Focus stacking

#15 Post by MicroBob » Sun Nov 24, 2019 2:45 pm

MichaelG. wrote:
Sun Nov 24, 2019 10:48 am
consider using a fine-focus stage for the specimen
A wide angle camera objective with its focus helix migth be a quick solution for a fine(r) focus stage

MichaelG.
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Re: Focus stacking

#16 Post by MichaelG. » Sun Nov 24, 2019 2:53 pm

Exactly what I had in mind, Bob
... I was just waiting to see if friend Glot would spot that opportunity.

MichaelG.
Too many 'projects'

Glot
Posts: 76
Joined: Thu Oct 17, 2019 7:23 am

Re: Focus stacking

#17 Post by Glot » Wed Jan 15, 2020 10:45 am

Thanks. Will look in to both options. At this point, I know nothing.

einman
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Re: Focus stacking

#18 Post by einman » Thu Jan 16, 2020 2:57 pm

Actually you can focus stack images quite well with a stereo scope. Assuming you have a good quality stereoscope lighting is the key. There is some compensation required due to the design of steresocopes greenough or CMO. This results in a less than perfect resolution but good enough.These are 2 of my first stacks. I have not played around with stacking since but plan on doing so later this year. I have seen some really impressive stacks.

Image[/URL]
Image[/URL]

einman
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Re: Focus stacking

#19 Post by einman » Thu Jan 16, 2020 3:35 pm

This is a non stacked image. If the specimen is situated in a relatively single plane such as the case with thss specimen stereoscopes do very well without stacking. This was a single shot non optimized lighting and my camera is not positioned as to minimize movement. I am not an expert obviously and rarely photograph. So in short you are doing well and a few tweaks can make a huge difference.

Image[/URL]

Glot
Posts: 76
Joined: Thu Oct 17, 2019 7:23 am

Re: Focus stacking

#20 Post by Glot » Sat Jan 18, 2020 7:12 am

Thanks for the suggestions. I am enjoying it immensely. Ken Walker used to post images on Bowerbird. Amazing detail

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