Help with picture technique

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

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bs0604
Posts: 40
Joined: Tue Feb 19, 2013 8:09 am
Location: Sarasota FL

Help with picture technique

Post by bs0604 »

this is my first attempt with using a Mitutoyo 10x objective and my extension tubing. I have not yet put flocking in the extension tubes but it seems that I am having an issue regardless, regarding clarity of the image. This was using a stackshot at 6 um & I had the same results when I first used it at 20 um. Processed with Helicon Focus. I set the settle time on the stackshot at 6 seconds to hopefully take care of settling issue. Any suggestions?

Image

lonepal
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Post by lonepal »

Hi;

What is the exposure time that you use?
Regards.
Omer

Pau
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Post by Pau »

I clearly see unsharpness due to movement.
It can be due to camera induced vibration (shutter or shutter + mirror) or to external vibrations (transit, wash machine...)

What camera model and camera settings do you use?
How stable is your setup? (pictures would clarify)
...a Mitutoyo 10x objective and my extension tubing
Be aware that the Mitu is an infinite corrected objective and it needs to be used with the adequate "tube lens" focused to infinite, do you use it just with extension?
Pau

ChrisR
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Post by ChrisR »

It does look like movement - try well diffused flash with rear curtain sync in a dull room, 2 second exposure (allows shutter wobbles to settle) mirror lockup.
Chris R

bs0604
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Joined: Tue Feb 19, 2013 8:09 am
Location: Sarasota FL

good point lineal

Post by bs0604 »

I am embarrassed to admit I simply set the exposure to "A". So I reshot increasing the ISO to 320 and setting exposure to 125th. I immediately noticed that my present lighting set up is insufficient, even when I moved the lights closer to the subject you can see it is still too dark. But at least it is looking a little sharper. I guess I need more lights. Is 125th of sec considered ok for these types of shots?Image

bs0604
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Joined: Tue Feb 19, 2013 8:09 am
Location: Sarasota FL

picture of my set up

Post by bs0604 »

Image

Using a mirrorless camera--fuji xpro2

bs0604
Posts: 40
Joined: Tue Feb 19, 2013 8:09 am
Location: Sarasota FL

my set up includes....

Post by bs0604 »

When I built the extension tubes I used two Raynox DCR-15 with reverse mounting. I tried to mimic a post elsewhere in this forum by rjlittlefield but don't know how exact my replica is.

Pau
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Post by Pau »

Yes, a big improvement but not good enough

1/125 is not a good speed for preventing camera induced movement at this magnification, in my experience between 1/15 and 1/125 are the worst scenario for camera induced vibration.

Not sure but likely your camera may have some sort of electronic shutter, if so it would be great to avoid vibration

If you don't have external vibrations test in a darkened room with 2s or longer exposure or with electronic flash as Chris suggests.
Pau

hero
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Location: California

Post by hero »

If at all possible I would avoid having your rig positioned diagonally on a tripod.

I have found that the simplest approach is to set the whole thing down on a table, horizontally. Clamp it down if you want. Then adjust the position of the subject accordingly. It's not ideal, but will easily beat your current configuration for stability. I've done exposures at 10x on FF around 1/20 - 1/50 s with a single Ikea Jansjo light this way without problems.

More light is better, not just for shortening the exposure time, but also for improving the quality of light as it becomes easier to achieve more even diffusion.

If all else fails, use a strobe. I have never had issues with motion blur when I use my flash.

bs0604
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Joined: Tue Feb 19, 2013 8:09 am
Location: Sarasota FL

Post by bs0604 »

My actual utilization was with the camera and extension tube close to horizontal and not as diagonal as shown in the setup photo. However, I did notice severe vibration of the extension tube with movement on the rail - the 6 seconds of rest before the subsequent picture appeared to allow the vibration to die out. I will try moving the whole set up off a tripod and on to a table top as you suggest. I am also working on rigging the set up so it stands vertically on the rack and pinion of a cannabalized dissecting microscope. Perhaps that will help.

bs0604
Posts: 40
Joined: Tue Feb 19, 2013 8:09 am
Location: Sarasota FL

any more suggestions.

Post by bs0604 »

This is the tip of a flower pistil using the microscope objective. 1/500 sec with iso 640. Still does not look quite right but I don't know if it is motion blur, inappropriate tube set up, lack of flocking (which I have not yet inserted) or simply need more refinement of my technique.

Image

hero
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Post by hero »

At 1/500 seconds, there shouldn't be substantial motion blur. However, subject movement during a stack can cause problems. A flower can move quite a lot as it wilts, so proper mounting is needed to mitigate this effect.

Flocking is more important than you might think, so I recommend that as your next step. Seeing your current tube lens setup, I would say it is a high likelihood that you are getting stray reflections somewhere in the optical path.

The other thing to consider is your stacking and retouching technique. You may be getting a lot of artifacts this way. I would recommend that you do some test shots of a flat subject, limiting the stack to only a few images.

rjlittlefield
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Post by rjlittlefield »

With a very shiny subject like this, you will probably get a cleaner result if you diffuse your light a lot more.

Directional light tends to produce hard bright reflections, which appear to move around in strange ways as you change focus.

The bright smears around some of the spikes could be from this effect, as well as from subject motion.

--Rik

ChrisRaper
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Post by ChrisRaper »

With the weevil photo, I'd say the problems are definitely to do with movement. Try using flash from a few directions, diffused through foam cups, but also shield the equipment from external light sources such as windows and ceiling lights.

Also remember that your camera has a huge lever on it (the lens+tube) and so they will be amplifying any vibration in the system. I'd try hanging it vertically or use a clamp to hold the lens steady. You can also introduce a longer wait between rail movements to allow the system to settle between shots or just use flash to freeze movement.

GrayPlayer
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Joined: Sat Nov 14, 2009 5:44 pm

Post by GrayPlayer »

Take a giant step backwards. Many images on this site are the results of hours and hours of concentrated work. I suffered from a similar fate, trying to capture a miniature world where I was a stranger. This is not a walk in the park shooting family. We delved into a world the size of a pin head or smaller. After you have your rig positioned and a subject in focus, bang on the table, jump up and down on the floor to observe any movement. Frustration is common but do not let it interfere with success!
Fred H.

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