Nikon objective advice

xenion · Post by **xenion** » Sat Aug 04, 2012 12:36 pm

I have a Nikon microscope with a few objectives with not too much info on them. I'm curious if these objectives can be used for macro photography or will they have too much chromatic aberration?
The Nikon ones don't have anything more on them than the picture shows. The Leitz/Olympus one only has a serial number or something like that on it: 442689.

rjlittlefield · Post by **rjlittlefield** » Sat Aug 04, 2012 1:39 pm

The two objectives on right appear to be Nikon CF N E Achromats, like HERE on pages 12 and 14.

The 10X (in the middle) is good for macro work on bellows. It has 5.2 mm working distance at 10X. That sounds short but actually it's OK for most purposes because of the conical shape of the objective.

The 40X on right should be used only through cover glass and has only 0.6 mm working distance. It requires a microscope with a condenser or some optically equivalent setup.

I'm not familiar with the Leitz/Olympus objective, but based on reputation it will show CA and based on overall length it will have only around 3 mm of working distance. I suspect you won't be happy with that one but since you already have it, you might as well try it and see.

--Rik

ChrisR · Post by **ChrisR** » Sun Aug 05, 2012 3:22 am

Being the "E"conomy range will mean the corners go off a bit, but the 10x will be more than good enough to get your technique nailed down before pondering more expense.

g4lab · Post by **g4lab** » Sun Aug 05, 2012 6:04 am

The objective on the far left is an Olympus objective mounted on a Leitz "PLEZY" adapter which is a spacer designed to make older objectives parfocal with newer DIN compliant objectives. The PLEZY has a slight negative lens in in it to correct the change in tube length it causes. The Oly objective wants to be used with a cover slip of 0.17mm thickness.

You can see that if the lenses are close to parfocal that the working distance of the Olympus 20x is closer to that of the 40x than to the 10x.
What Rik said about chromatic correction still applies. The 20x would be looking for a contemporaneous Olympus ocular to correct its built in chromatic difference of magnification.

Litonotus · Post by **Litonotus** » Sun Aug 05, 2012 7:53 am

I once compared the Nikon E achromat and PZO achromat objectives - I noticed almost no difference in image quality. PZO 40x achromat objective cost is about $10.

xenion · Post by **xenion** » Sun Aug 05, 2012 2:50 pm

Thanks for the information! So, briefly, these are good starter objectives.
Besides the ones on the picture i also have a Nikon 4x of the same type as the other Nikons.
I already have some extension tubes (Canon mount, 68mm in total), so regarding this topic I would need a RMS to M42 adapter like this one and a M42 to Canon EF adapter like this one to get started. Or would bellows be a better choice?

rjlittlefield · Post by **rjlittlefield** » Sun Aug 05, 2012 3:12 pm

Working with the extension tubes is fine and it's a cheaper way to start.

The cone adapter provides about 53 mm of extension. Add to that 68 mm from a typical set of extension tubes, plus the 44 mm of flange distance for Canon EF and EF-S mounts, and you have potential 165 mm total extension. That will work fine at a bit higher than nominal magnification, or take out a tube, if you like, to get closer to the 150 mm spec.

Bellows would give you more ability to adjust the extension, but there's certainly no need for that to get started.

--Rik

xenion · Post by **xenion** » Tue Aug 07, 2012 10:40 am

Thanks, I'll order some stuff and will try it out.

xenion · Post by **xenion** » Sat Sep 01, 2012 12:12 pm

In the meanwhile I've received the stuff I had ordered and have shot my first pictures with the 4x and 10x Nikon objectives using the Stackshot focus rail.
It's great to see the world at such high magnification

I'm using 56 mm of extension rings in total, so I should have about 153 mm of total extension. I'm using a continuous light source from some LED lights.

I'm not yet fully satisfied with the sharpness so far, is this due to the objective or can there be another cause?

Single shot:

And a 100% crop of that picture:

(Subject is the slime mold Diachea leucopodia)

rjlittlefield · Post by **rjlittlefield** » Sat Sep 01, 2012 1:54 pm

You definitely have motion blur. Notice that all the smallest highlights show as elongated streaks instead of small symmetric blurs like you should be getting from point sources. EXIF shows 1.6 seconds exposure time. This is very vulnerable to environmental vibration, and somewhat sensitive to mirror/shutter vibration. Try illuminating with electronic flash, and use shutter lockup if possible.

--Rik

xenion · Post by **xenion** » Sun Sep 02, 2012 2:29 pm

Thanks for your comment Rik, I don't have a decent external flash (yet).

Today I've added some more light to my setup and tried to find the cause of the vibrations. Most of the vibration was from the shutter, switching to live view using silent mode 2 (Canon 40D) kills most of the vibration.
But when in live view and zooming in to 10x there is still a very little bit of continuous vibration which I can't seem to get rid of, I guess this is caused by some external factor(s).

The results are better already (100% crop of the same subject again):

Martin

rjlittlefield · Post by **rjlittlefield** » Sun Sep 02, 2012 3:53 pm

Yes, this is much better. You could stack this, sharpen with USM in Photoshop, and it would look very nice.

--Rik

xenion · Post by **xenion** » Mon Sep 03, 2012 12:45 pm

Thanks for you help Rik, going to post my results.
Any further picture quality improvements will come from getting rid of the remaining (very little) vibration and a better objective?

Charles Krebs · Post by **Charles Krebs** » Tue Sep 04, 2012 11:31 am

But when in live view and zooming in to 10x there is still a very little bit of continuous vibration which I can't seem to get rid of, I guess this is caused by some external factor(s).

You should try to find the source and eliminate it if possible. It is always frustrating (but usually also interesting) to track down the source(s) of such external vibration. Sometimes you can solve it, sometimes it is difficult.

I live in a typical wood framed house in a suburban area. Some of the things I have come across over the years...

Vehicular traffic passing by outside the residence (primarily trucks). A cloths washing machine or dryer operating in the house. Music from an audio system (particularly strong bass). People walking about in another part of the house (amazing how some people walk "softly" while others just seem to have heavy feet

) . Air currents from a forced air heating/cooling system or a cooling fan, even when barely discernible on your "skin". Fiber optic illuminators that have cooling fans... not necessarily from the air currents, but some seem to have a slight imbalance in the fan/motor mechanism and can be problematic.

Although I am working on a lower level concrete floor (good) my workbench is connected to a frame wall (bad). This is why I need to be more mindful of various household potential causes. In a previous location I was set up on a framed floor and that was perhaps even more prone to certain household vibrations.

I have also done some work in a high-rise building in an urban environment. It was nearly impossible to get things "dead calm". In this instance I think is was primarily caused by the buildings (constantly on) heating/cooling equipment, but I seemed to notice that the elevator operation and heavy street traffic added to it at times.

xenion · Post by **xenion** » Thu Sep 06, 2012 9:51 am

I live in a concrete house, the only source I can think of right now is my PC which is in the same room. I will have a look if it makes a difference if I switch off my PC.