40x Objectives Comparison

[75RR]

Decided to compare my 40x Objectives, mostly because I was a little disappointed with my Plan 40x.
Not only does it seem a bit washed out but it also consequently requires closing down the diaphragm that much more. Even then it does not impress much; yet I can not see any delamination to account for this.

Perhaps a more valid test would be to try to optimize each objective no matter what one had to do in terms of aperture or post processing, instead I tried to treat them all equally.

For the test I set the aperture at 1/7 of its range using a reticule (not sure if there is a standard way to measure this), apart from setting the level to what each one required in Photoshop, all other adjustments were identical.

I have four 40x objectives - I tested all of them.

They are:
F 40x/0,65 part of a semi-plan set I bought
Plan 40x/0.65 bought as part of my DIC preparations
Phase Ph2 40x/0,65 came with my Zeiss RA
Winkel 40x/0,65 came with my Zeiss Junior

I used Diatom Navicula lyra from Kemp's 8 Form Test

So, how bad is the Plan 40X?

Note: As to the dust specks - every time I try to clean the sensor I take a few away, add a few more and move the rest around a bit. Sorry.

[billbillt]

I don't see it as really "bad", I just don't see where it does much....

[75RR]

I don't see it as really "bad", I just don't see where it does much....

You must not expect it to have more depth of field, I believe Plans just extend the area in focus nearer to the edges of the field of view.
I am looking for more resolution/sharpness and a reason is washed out.

[billbillt]

It does appear to be slightly more in focus at the edge... Just slightly... Maybe Plan objectives are not worth the extra money for hobby use....

[75RR]

It does appear to be slightly more in focus at the edge... Just slightly... Maybe Plan objectives are not worth the extra money for hobby use....

This image covers a small central area of the field of view, the Plan "advantage" should not visible. Think concentric circles, a normal objective would perhaps cover from 1/2 to 3/4, the plan would cover all of it, but only on the same plane of focus. Plans are best for viewing microtome cut sections that extend over most of the field of view, i.e. very flat areas of a uniform thickness.

[billbillt]

To my eye, I can see a little more in focus or sharpness at the edge with the plan objective...

[75RR]

To my eye, I can see a little more in focus or sharpness at the edge with the plan objective...

The second enlarged image (F) looks sharper to me.
At that distance from the center of the image I do not think we should be looking for edge improvements.
All four objectives should cover that area easily.

In terms of dot (punctae) resolution I find the order from best to worst:
F, Phase, Plan, Winkel.
I suppose I should do an individual optimized test.
As far as the Plan goes it would seem that the camera picks up more than the eye does.

[billbillt]

As you wish..

[75RR]

Unprocessed F and Plan images, complete area:

[Dennis]

I got a similar story,
When I was buying Plan objectives I bought a semi set of Nikons and I use a Nikon and the seller said Excellent condition- They are fantastic!!!
OK around the same time I bought a Carl Zeiss made in Germany Plan 16X, the seller said crystal clear and it cost like 60 bucks- CRAP!
BUT....... when I look inside the eyepiece instead of using the USB camera it looks great.

In your pics I think the Plan does the edges best and inside is 2nd best (only a opinion not a fact) than first one I like the brighter look.
The 4th one is the worse.

BTW I bought a Olympus BH BHC Phase Contrast microscope for a little over 3 bills and I'll let you know if I need help on that! Looks like a really great microscope!!!

-Dennis

[75RR]

BUT....... when I look inside the eyepiece instead of using the USB camera it looks great.

That might be down to the camera.

BTW I bought a Olympus BH BHC Phase Contrast microscope for a little over 3 bills and I'll let you know if I need help on that! Looks like a really great microscope!!!

I have no personal experience with them but I have heard good things about them - is it in working order?

[Dennis]

75RR-

No question that the camera is the weak link. i can see Rotifer feelers spinning away looking in eyepiece and hard to get on film!!!!!!

It looks good in pics (Olympus microscope) , a sticker says serviced in 2007, and comes in original wood box. (good sign also)

-Dennis

[75RR]

It looks good in pics (Olympus microscope) , a sticker says serviced in 2007, and comes in original wood box. (good sign also)

Make sure you do some research on that type of microscope first (do you need it? why? how does it compare with other models, average price, price of parts you may want to get i.e. objectives, trinocular head etc... also ask the seller as many questions as you need to.
As I said, I have no experience with Olympus, any help will be very general in nature.

[Dennis]

Why do you have???-

Zeiss Standard Junior (1952 - 1957)
Zeiss Standard RA 1960's
Olympus E-p2

Oh you mean perhaps just a lens. Anyhow it has been bought and is on the way. It is exclusively for Phase Contrast use.

-Dennis

[75RR]

Why do you have???-

It is called a signature
➔ User Control Panel ➔ Profile ➔ Signature
It is just a list of my equipment.

Anyhow it has been bought and is on the way. It is exclusively for Phase Contrast use.

Good luck.

[Charles]

I think Dennis saw the Olympus E-p2 camera in your sig block and probably thought it was a microscope.

The last two shots do show quite a difference. Maybe your Plan 40 needs cleaning?

[75RR]

I think Dennis saw the Olympus E-p2 camera in your sig block and probably thought it was a microscope.

That could be it.

The last two shots do show quite a difference. Maybe your Plan 40 needs cleaning?

Will clean more carefully this time.

[Dennis]

yup I know its a signature (Geez internet since 1998!)

and everyone has their microscopes listed and I thought you were a Olympus microscope user.

Anyhow...

-Dennis

[75RR]

The last two shots do show quite a difference. Maybe your Plan 40 needs cleaning?

Will clean more carefully this time.

Had a careful look - delamination. Damn!

[Charles]

It's rare for a plan achro to be delaminated. Maybe someone used it with oil and has oil intrusion.

[75RR]

It is on the bottom lens.
Can a 40x be opened and cleaned?

[Charles]

I've never tried to fix an objective.

[billbillt]

Member Rodney here on this forum has worked on objectives... Maybe you could contact him for assistance?...

[apochronaut]

That hazy or fogged quality to the image is almost always a sign of delamination, if a film on the back or front element has been ruled out. OIl impregnation usually causes a skewed image, no image, or a change in the focal point. I have had moderate success fixing them. If it is an older lens and the cement is Canada Balsam, often the lens can be soaked in 100% ethyl alcohol ,just until the balsam resets .You never know how long it takes. They quickly dry and some have complete recovery. I am about 50% on repairing those.
If the element can be removed as a raw doublet, the success is high. If that doesn't work, at least they can be separated and recemented, either with balsam or a synthetic cement( available on ebay for a few bucks). If the lenses are furled into a setting , then soaking is more difficult and they usually cannot be separated and re-cemented, although I have pickled some of those back into shape too.
If it is a synthetic cement( used since about the 50's increasingly and now almost exclusively), they sometimes can be softened and reset with heat. Without knowing what the cement is, a solvent can't be determined.
Sometimes a damaged one can be found and 1 made out of 2, or 3, or 4...
I once had a Leitz 45X objective with a very low contrast image, that otherwise was sharp. It was almost new and I could not find anything wrong with it. It had a bit of German writing on it and a serial #, so I did some digging and found out that it was supposed to be like that because it had been made for specifically examining film emulsions.

[75RR]

Hi apochronaut,
this is the objective (same one from ebay) http://www.ebay.com/itm/Carl-Zeiss-Plan ... 3f4f80b3ca

Image taken though Optovar - Think it is on bottom lens.

[apochronaut]

On the front surface of the bottom lens?

[75RR]

Inside, covers about 3/4 of the bottom lens. You need to view it at an angle to see it.

[apochronaut]

I've never seen a de-lamination that looked like that. Usually de-lamination has either a flowing or curved wispy form. which looks almost like condensation on the lens, distinct small air bubbles or an amoeba like form , where air has crept in along one seam and the lenses have separated. Always the curvature of the lenses contributes to the form.
I have seen this sort of thing as dried crud on the front lens. Oil left to dry usually and it can be tenacious to get off. You end up getting it off in dribs and drabs from the thinnest to thickest part, so when you are half way through there are lots of jagged edges and lines where some bits have been scraped a bit. I usually use soft newsprint type paper for that job, so it has a bit of abrasive and gripping power----not enough to scratch glass but enough to grab hold of murk. I don't do this on coated optics, which brings me to this;
The other possible thing is , someone has had this apart and ineptly cleaned it, accidentally removing and scratching off the coating in the centre area of the lens. Some of the old interior coatings on European lenses were very soft and vulnerable to this kind of damage. It can have this kind of look. Often ,it doesn't really affect the lens much but It could induce enough ray scattering to cut the contrast down, depending on the location of the damage.
THis really looks like it has been rubbed at. If it was old oil that had entered and settled on the inside of the bottom lens, I would think it would have a more rounded less scratchy look to it.

[75RR]

Thanks apochronaut,
Agree it does not look like delamination so thought dry oil sounded like a good candidate.
"scratching off the coating in the centre area of the lens" sounds a lot worse.
I will have a careful look in the morning and see if I can provide more details.

[gekko]

Too bad. Clearly the contrast is shot. By taken "through the Optovar", I assume that you meant the Bertrand Lens focused on the damaged surface? I agree with apochronaut that this does not look like delamination. My (quite uninformed) guess: it could be dried oil, but I think it also could be that water with salt or other minerals has entered the objective and the water dried out leaving the deposits on the glass. What does it look like if you use polarized light and look at it with the Bertrand lens?