First attempts with a microscope objective

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DrLazer
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First attempts with a microscope objective

Post by DrLazer »

Well I didn't expect it to go well. But I thought I would show my results as I iron out the creases. Well I say creases, they are more like big holes. I say big but they are more like huge :S

I have an Edmund Optics Nikon 10x Achromat, it's attached to the flat style adapter not the conical one. All adapters and rings including the brass ring on the objective are lined with protostar.

An earwig was knocking around in my front room, so I tried to gas it with nail polish remover. It almost certainly put him to sleep, but indefinately was a little longer than intended, whoops. Oh well, I have a stationary subject for sure now.

Here is the result straight out of Zerene Stacker (not like me at all, I photoshop the life out of all my images).

Image
http://flickr.com/gp/51782392@N06/L84nE1
(I hope that works, it's one of those guest pass thingies)

The first problem I have encountered .... the vertical on my sensor is 13mm, I mounted the objective and got a tape measure in focus. 13mm sensor at 10x should mean I see 1.3mm on the viewfinder. However, I can see exactly 1mm. My magnification is a little higher than I wanted it to be. (Does anybody know how to work out what that magnification is, I suck at maths?) but this is with my bellows fully closed ... is that normal? How would I get down to 8x for example?

The image is stacked with 0.02mm steps. I thought that would be enough but the banding at full resolution is obvious. I think doubling that will be safe.

The earwig has hairs all over him. I couldn't believe that. Hairs just get finer and finer and never seem to stop being a problem for me. I need to figure out someway of removing those hairs which I cant even see with my naked eye. Anybody have any good techniques for this?

The flash is placed on the wrong side and I diffused it through a yoghurt pot, I think I need a ping pong ball, I'll pop out for one tomorrow.

Last thing I noticed was the streaking on the edges :shock:
I thought I would have eliminated them with the linear stage but I cannot figure out why I am getting them.

lauriek
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Post by lauriek »

What body are you shooting with, and what else except the bellows is in-between it and the lens?

Re hairs, the best thing is to use a stereoscope or a magnifying glass at least to view the critter and dust-em off... I use a fine artists sable brush for this, I tweak a couple of hairs to stick out sideways and try to pick off individual bits of gunk with the end of a single hair.

Having said that I quite often start off just gripping the bug very well by a leg or two in some tweezers and blowing at it really hard!

Buy more than one ping pong ball, cutting them up can go wrong...

lauriek
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Post by lauriek »

Okay I just read your other thread, I see you're shooting the Lumix so you've a 4/3 sized sensor.

One way to work out the magnification you're achieving - does your camera body have some mark which tells you where the sensor plane is? Sometimes on the top, sometimes on the bottom. Measure from this line to the shoulder of the objective. Then compare that to the designated extension for the lens. (If it's not marked you can try to estimate where the sensor is by looking in the front and then estimate some top of body feature which you think is in about the right place!)

So for instance if the objective is designed for 160mm and you have 200mm of total extension then you'll be achieving 200/160x10 =12.5x

I notice you have a chunky adapter between the camera and bellows, suspect that's what's pushing up your magnification. Is that a micro4/3->OM adapter? I'm still surprised you can't get down to 10x though...

Of course if your sensor is 13mm high and you see 1mm exactly on that axis then you're shooting at 13x mag.

DrLazer
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Post by DrLazer »

What body are you shooting with, and what else except the bellows is in-between it and the lens?
Lumix G10. M42 adapter, then bellows, then the lens. I'm thinking of taking the bellows out of the equation to see if it maybe goes down to 8x or something.
Re hairs, the best thing is to use a stereoscope or a magnifying glass at least to view the critter and dust-em off... I use a fine artists sable brush for this, I tweak a couple of hairs to stick out sideways and try to pick off individual bits of gunk with the end of a single hair.

Having said that I quite often start off just gripping the bug very well by a leg or two in some tweezers and blowing at it really hard!

Hehe, I thought about doing that before but was worries about spitting on it. I'll give it a good old mega drive cartridge fix.
Buy more than one ping pong ball, cutting them up can go wrong...
What am I ... rich? :) I'll pick a pack up from Decathlon. I guess you just cut a hole at the back for the bg (some plasticine) and a hole at the front for the lens to poke through, and then blast the flash from above/to the side.
[/quote]

DrLazer
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Joined: Wed Feb 16, 2011 4:45 am

Post by DrLazer »

I notice you have a chunky adapter between the camera and bellows, suspect that's what's pushing up your magnification. Is that a micro4/3->OM adapter? I'm still surprised you can't get down to 10x though...
u4/3 -> m42, I think it's chunky to maintain infinity on old lens. Doesn't help me out in this situation though.
Of course if your sensor is 13mm high and you see 1mm exactly on that axis then you're shooting at 13x mag.
Duhhhhhhhhhh, god I'm crap at obvious.

Cheers Laurie.

rjlittlefield
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Re: First attempts with a microscope objective

Post by rjlittlefield »

DrLazer wrote:Well I didn't expect it to go well. But I thought I would show my results as I iron out the creases. Well I say creases, they are more like big holes. I say big but they are more like huge :S
I prefer to think of situations like this as "presenting some opportunities for improvement". :)
I have an Edmund Optics Nikon 10x Achromat, it's attached to the flat style adapter not the conical one. All adapters and rings including the brass ring on the objective are lined with protostar.
All good.
An earwig was knocking around in my front room, so I tried to gas it with nail polish remover. It almost certainly put him to sleep, but indefinately was a little longer than intended, whoops. Oh well, I have a stationary subject for sure now.
That happens sometimes. It's always saddening when a critter dies and you didn't intend it to. But trust me, this happens to other people too.
Here is the result straight out of Zerene Stacker (not like me at all, I photoshop the life out of all my images).
Seeing it before any treatment is helpful here.
The first problem I have encountered .... the vertical on my sensor is 13mm, I mounted the objective and got a tape measure in focus. 13mm sensor at 10x should mean I see 1.3mm on the viewfinder. However, I can see exactly 1mm. My magnification is a little higher than I wanted it to be. (Does anybody know how to work out what that magnification is, I suck at maths?) but this is with my bellows fully closed ... is that normal? How would I get down to 8x for example?
The objective delivers 10X when the shoulder of its mounting threads is 150 mm away from the camera sensor. See HERE, image #1. If that distance is less than 150 mm, and still you're seeing a field that's only 1 mm high, then I'd bet that one or the other measurement is messed up. It's awfully easy to forget about thickness of the lines on a ruler, for example. (Been there, done that.)
The image is stacked with 0.02mm steps. I thought that would be enough but the banding at full resolution is obvious. I think doubling that will be safe.
Microscopyu lists a DOF of of 8.5 µm = 0.0085 mm for 10X NA 0.25. Or maybe it's 14.4 µm, which is a different figure that microscopyu also lists on a different page for the same 10X NA 0.25. Yes, 0.010 mm sounds like a good next try.
The earwig has hairs all over him. I couldn't believe that. Hairs just get finer and finer and never seem to stop being a problem for me. I need to figure out someway of removing those hairs which I cant even see with my naked eye. Anybody have any good techniques for this?
There's a product called "Nair" that addresses this issue for humans. Probably doesn't work on insects, though -- different chemistry. ;)

Oh, I see! You're probably talking about those things that look to me like long skinny moth scales. That forked one on the very right reminds me ever so much of the thorax scales of certain moths. See HERE for an amusing story about one of those.

If you have a low-power dissecting scope available, using that to examine the subject before photographing it would help a lot. Something around 10-20X.

Also, for non-fuzzy critters like this earwig one effective approach is to just wash them. A little soap in the water will help wet the cuticle and debris so it comes off better. Alcohol also works, and that dries faster. Washing an earwig is notably simpler once it's dead. They wiggle something awful if submerged while alive.
The flash is placed on the wrong side and I diffused it through a yoghurt pot, I think I need a ping pong ball, I'll pop out for one tomorrow.
Try thin paper. I get a lot of mileage from Kleenex tissue. It's often simpler to work with than a ping pong ball.
Last thing I noticed was the streaking on the edges :shock:
I thought I would have eliminated them with the linear stage but I cannot figure out why I am getting them.
This is almost certainly a misalignment problem. The optical axis is not lining up with the axis of physical movement. See HERE on the Zerene Stacker website for some explanations and suggestions.

--Rik

DrLazer
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Post by DrLazer »

I prefer to think of situations like this as "presenting some opportunities for improvement"
That's a nice way of viewing it. :)
The objective delivers 10X when the shoulder of its mounting threads is 150 mm away from the camera sensor. See HERE, image #1. If that distance is less than 150 mm, and still you're seeing a field that's only 1 mm high, then I'd bet that one or the other measurement is messed up. It's awfully easy to forget about thickness of the lines on a ruler, for example. (Been there, done that.)
Spot on Rik, the increments on my ruler are 2mm. Who made this ruler!
Recalculating my magnification now, I am only at 6.5X, and this earwig's head fills the frame! I have the El-Nik50mm and the Edmund 10x, I have a distinctive gap at around 6x - 8x where I will be outside the quality range of both lenses. The earwig gets his revenge!
Microscopyu lists a DOF of of 8.5 µm = 0.0085 mm for 10X NA 0.25. Or maybe it's 14.4 µm, which is a different figure that microscopyu also lists on a different page for the same 10X NA 0.25. Yes, 0.010 mm sounds like a good next try.
I hope it is 14um, I am pretty sure my micrometer moves in notches of 10um (50 notches moves half a mm). The notches are 1mm in size though so I could eyeball half notches. It is interesting that Newport say that standard resolution micrometers offer movements of 1um. I thought I had the standard resolution micrometer. Obviously not. It also states that with a differential micrometer I can get movements of 0.1um, nice to know I can upgrade in the future.
Oh, I see! You're probably talking about those things that look to me like long skinny moth scales. That forked one on the very right reminds me ever so much of the thorax scales of certain moths. See HERE for an amusing story about one of those.
Not much gets past you does it. Those are definitely moth scales. I think I had a Quaker in the same pot I stored Mr. Earwig in after his humane gassing. (I like to tell myself it was humane).
They wiggle something awful if submerged while alive.
Speaking from experience Rik?

Thanks for the response. I will get back to it and show some progress once I have got these bugs fixed at work.

DrLazer
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Post by DrLazer »

once I have got these bugs fixed at work.
Software bugs, not wiggly ones.

rjlittlefield
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Post by rjlittlefield »

DrLazer wrote:It is interesting that Newport say that standard resolution micrometers offer movements of 1um. I thought I had the standard resolution micrometer. Obviously not. It also states that with a differential micrometer I can get movements of 0.1um, nice to know I can upgrade in the future.
I'm guessing that Newport's spec of "1 µm sensitivity" comes from exploiting a vernier scale on the micrometer. See HERE for example.
I have the El-Nik50mm and the Edmund 10x, I have a distinctive gap at around 6x - 8x where I will be outside the quality range of both lenses.
Yes, that range is a bit awkward. Consider combining a Nikon CFI60 Plan 10X NA 0.25 objective with a ~100 mm tube lens to yield ~5X as illustrated HERE. That objective covers a 5 mm field with high quality image. At 5X, perhaps its biggest problem is that the resolution may exceed the camera sensor while the DOF is shallower than you'd like due to the wide aperture.
They wiggle something awful if submerged while alive.
Speaking from experience Rik?
Sure 'nuf. We grow grapes, and the bunches often harbor earwigs. It's quite common to find them rinsed out into the sink. They wiggle something awful!

--Rik

DrLazer
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Post by DrLazer »

Thanks Rik. I'm not sure I understand entirely though. I thought my micrometer was marked up in 0.5mm notches. It may not be, I'm just confused really.

So .... I got a bag of ping pong balls. I needed to make a nice clean hole in one for the lens. I thought "ill burn it .. thats a good idea". A took a lighter to it and got the fright of my life. A blazing ball just fired around my front room, eventually settling and burning the dining table. Whoops.

I cut the second one! Placing Mr. Earwig inside on a pin, a more front on angle this time. I overexposed this one too. I found the mark on the body as Laurie suggested and I believe I have 80mm of total extension.

Here is a quick stack straight out of zerene. I know it has transparency issues and such but it's just a demonstration, no retouching just yet. Still a bit dirty but nothing I couldn't photoshop away.

Image
http://flickr.com/gp/51782392@N06/X38Y0V

I think 10um is ok. I don't think I can see any banding but let me know if you can see some.

I extended the bellows to 150mm and shot a stack which I think will be much better (even though its got a lot less earwig in) and adjusted the lighting too. It's running now, I'll post it when it pops out.

lauriek
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Post by lauriek »

Celluloid is really quite highly flammable!!

Sorry still laughing can't comment any further yet!

DrLazer
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Post by DrLazer »

Aaaaarggghhh what happened to this! :shock:
Image
http://flickr.com/gp/51782392@N06/w4YCZ0

ChrisR
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Post by ChrisR »

The starry highlights? Light's not diffuse enough. It's an effect I don't think we've seen a good explanation for. If you rack the focus in and out you can often see the lens seem to focus on rays of light in the air as they bounce off the subject. Which makes no sense to me!

The general haziness of the earlier ones often seems to come from light getting into the lens other than from the subject. Try a duller background and make sure the front glass is shaded. Also, as I'm sure you know, if you have a lot of out-of-focus stuff in the image it'll effectively cause a fogging haziness. Enter substacks...

I'm always surprised at how a diffuse light can look much more direct at 10x than it does at 3x. I don't know why it does that!

rjlittlefield
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Post by rjlittlefield »

About the starry highlights, be on the lookout for ways that the light can reach your subject without going through the diffuser. Especially with pingpong balls, it's pretty common for there to be slits that the light can get through straight from the flash, or sometimes it goes around the diffuser via a reflection off some nearby shiny surface, or direct to a corner of the flash you didn't think about.

This is less of a problem with diffusers like facial tissue that can be draped clear around the subject and lens.

--Rik

DrLazer
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Post by DrLazer »

Cheers for the replies guys. I'm going to look for another subject I think, maybe something a bit smaller. I'm going to try out a Kleenex as a diffuser too. I feel like Rik is being friendly but is one step away from throttling me and force feeding me Kleenex :)

slight tangent but a couple of interesting links with ping pong balls in them.

http://www.youtube.com/watch?v=Vw7psWrzHH8
http://www.youtube.com/watch?v=s0uX7DIkT3E

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