Mouse Blood

Mitch640 · Post by **Mitch640** » Sun Nov 21, 2010 12:21 pm

Caught a mouse today and got some blood to look at. First time I have seen any blood. It still moves around after more than 2 hours under a coverslip.

Here's the video of the blood.

The green is obviously CA from the E 40 Nikon objective.

As you can imagine, I am really looking forward to some better quality objectives.

Cactusdave · Post by **Cactusdave** » Sun Nov 21, 2010 2:07 pm

Is that green and purple fringing visible through the eyepieces as well as in the camera image? I've had that kind of chromatic aberration when there has been a mismatch in compensation for chromatic aberration between the objective and the photoeyepiece used to couple the camera. I don't think the objectives are entirely to blame. They may be plain vanilla, but they are decent enough quality. What lens are you using for camera coupling?

Mitch640 · Post by **Mitch640** » Sun Nov 21, 2010 2:20 pm

Dave, I was using a 10x CF Photo relay eyepiece dropped down inside an adapter I bought for the EOS mount. So, everything was Nikon, however, the 40x objective is not CF, it's an E designation, which means nothing to me. It's not a CF Plan Acromat though. Which I hope to be buying soon.

I also have another costlier adapter with a 2x lens built into it, and I get the same CA from it as your seeing here. And something that makes no sense, about the same magnification. Go figure.

I do not see any purple or green fringe through the eyepiece though. And in fact, this particular shoot today was to check the fringeing from both adapters. Now I have my answer.

Mitch640 · Post by **Mitch640** » Sun Nov 21, 2010 5:56 pm

Is that green and purple fringing visible through the eyepieces as well as in the camera image?

Dave. I must correct my statement. I just went back to check that smear, and under the 40x objective, yes, I see the green and purple fringing. It looks exactly like the third image above. Now I am confused.

Also, the blood is still alive. Still moving on it's own. I can see I will have to find a very sharp pin soon.

Cactusdave · Post by **Cactusdave** » Mon Nov 22, 2010 1:44 am

The movement of the blood corpuscles will be due to tiny currents of fluid under the coverslip caused by heating from the light source and evaporation at the coverslip edge. Movement of really small particles in fluid can also be caused by Brownian motion (http://en.wikipedia.org/wiki/Brownian_motion) . The red corpuscles (erythrocytes) don't have any method of movement in themselves, though the rarer white cells (leucocytes) are able to move slowly by the same method as amoebae.

The classic subject for setting up objectives and attached cameras, as well as being intrinsically attractive, are mounted diatoms. I thoroughly recommend them. They certainly won't go anywhere while you are trying to focus on them.

The fact that you can see fringing through the eyepieces as well as photo lens raises the question as to what eyepieces you are using? The X40 E plan probably expects Nikon compensating eyepieces such as the HKW 10X.

rjlittlefield · Post by **rjlittlefield** » Mon Nov 22, 2010 2:01 am

This does not look at all like the form of CA that requires a compensating eyepiece. That form manifests as color fringes that are radial with respect to the center of the image. These are radial with respect to each blood cell. What I see here looks more like longitudinal CA in which different colors focus at slightly different depths. Unfortunately it is quite common.

The "E" objectives that I know do come from the CF series. There may have been older E's that did not, but if so I don't know about those.

--Rik

Mitch640 · Post by **Mitch640** » Mon Nov 22, 2010 4:16 am

The Oculars are CFW 10x. It appears that that E 40x is the only lens that shows the green and purple cast, for whatever reason. I have just checked the other two Nikon lenses and the three Chinese Plan lenses I got with that other scope and the E 40 [it does not say Plan on it] is the only one that shows fringing in green and purple.

Dave, are you saying mounted diatom slides are used like a tool, to check optics? That makes sense as they are a known quantity. I have only seen a few diatoms in my most recent river water samples here, and they were showing much more detail through the Fluophot than through my other scope.

Cactusdave · Post by **Cactusdave** » Mon Nov 22, 2010 4:18 am

Thanks Rik, I stand corrected about the E plan X40, I didn't know it was part of Nikon's CF objective programme. As has been noted elsewhere on this site, the whole question of what Nikon objectives belong to what series, what tube length and what system of correction of CA if any they are designed to work with, is complicated and confusing. The designation on the objectives themselves is hardly helpful either.

Nevertheless I am surprised to see this degree of chromatic aberration in a quality microscope properly set up if objective and eyepiece are also correctly matched. I believe CA can also arise if a compensating eyepiece is used with an objective such as a CF that does not require such an eyepiece and also if eyepieces from another manufacturer are used which provide greater compensation for CA (over compensation) or less compensation (under compensation) than the objective manufacturer's own matched eyepieces. Is that a correct understanding?

I appreciate this may not be the souce of the CA Mitch is seeing in his particular case.

David

Cactusdave · Post by **Cactusdave** » Mon Nov 22, 2010 4:32 am

Just seen your latest post Mitch. The eyepieces are CF and should match CF series objectives. Maybe there is an issue with your X40. Have you checked the front element for cleanliness, especially a film of immersion oil from a previous careless user. Immersion oil smears on a non-immersion lens is a frequent cause of problems. A reversed eyepiece makes a handy 'magnifying glass' for critical examination of objective front elements.

Yes mounted diatom slides make good 'test objects' to check that your optics are all working well together and as a practise target for photography and stacking technique. Their use as tests for the setting up of the microscope and checking its resolving power go back to the early days of Victorian microscopy.

David

Mitch640 · Post by **Mitch640** » Mon Nov 22, 2010 5:01 am

I can't thank you guys enough for all this help and time your giving my problem. Just wanted to say thanks.

The reversed eyepiece is a great trick, and it appears to be in need of a cleaning itself, but it did show me that all the lenses that came with the Fluophot are either filthy or scratched, or both. I have just spent the last 15 minutes cleaning them all with a camera lens microfiber cloth with a spray of anti static lens cleaning fluid on the cloth, then dry wipe. One of the objective rear lenses, the 10x is so deep in there I can't get to it. The 4x looks like someone cleaned it with sandpaper in a swirling motion. I had planned on replacing all of them anyway. Now it looks like I will need to.

I had read somewhere that a certain diatom has holes in the shell that are always a certain size and is used as a standard for measuring light in some way. To me, that is one of the most amazing things I have heard of. I love this hobby. Where can I get prepared slides for this?

NikonUser · Post by **NikonUser** » Mon Nov 22, 2010 5:30 am

Mitch:
Diatom slides are the classical lens testers.
Not sure how readily available they now are.
Years ago, 1950s, prepared slides could be readily bought from Brunel Microscopes in London.
Plenty of live ones in your local ponds/rivers but these live guys move really fast when seen at 500x.
Other readily available good test subjects are moth/butterfly scales. For reflected light look at the entire wing, for transmitted light simply brush a few scales onto a a slide.
Several images of such scales on PMG.net

Mitch640 · Post by **Mitch640** » Mon Nov 22, 2010 5:40 am

I have seen the scale pics by Charles and others. Fantastic natural art. If I could take picutres half as good, my printing bill would be through the roof. LOL

I did a Google search a few minutes ago and did find a place that sells prepared Diatom slides, here. It's near the bottom of the page under Test Diatoms. Just from the web pictures though, they are no better than what I have seen in my scope. LOL

Cactusdave · Post by **Cactusdave** » Mon Nov 22, 2010 5:41 am

Be wary when cleaning objectives. Generally less is more. I use lens tissue rather than cloth myself which I think is better left for camera lenses and binoculars. I never try to do more than the front element There shouldn't be much more than dust on the rear element which can be disloged with a hand blower, not one of those compressed gas things that spatter propellant liquid everywhere. Don't try any disassembly on objectives, it invariably leads to tears unless you really really know what you are doing.

The classic source of modern diatom mounts is Klaus Kemp http://www.diatoms.co.uk/ He offers a mount of 8 classic test diatoms varying in size so that it is useful from about X20 up to X100. It costs £17, he ships worlwide and is a nice guy. Lots of diatom slides of varying quality appear on Ebay too. Unless you want to catch the slide collecting bug look out for things that are called diatom test slides or some similar form of words. There is no need to pay huge amounts of money. You might also have someone more local to you prepared to let you have a few slides to play with.

David

Mitch640 · Post by **Mitch640** » Mon Nov 22, 2010 5:49 am

HAHA, OK, I have heard of miniature art, but this is on a whole other level. What are you guys doing over on that side of the pond?

NikonUser · Post by **NikonUser** » Mon Nov 22, 2010 5:59 am

Mitch: I thought you were mainly interested is testing optics rather than the art.
Moth scales have a lot of useful detail and are free. Heck if you can't find a moth wing I could let you have one from my 10,000+ collection of pinned moths (hence the moniker "Mothman").