Zeiss 4X objective

[keithstout]

I need some help. I need a 4X objective for my Zeiss Standard model 18 scope. I need an achromat, which, I believe, will give me maximum working distance for diatom picking and glass needle positioning/centering. My Zeiss has the 160mm objective specification. I see objective model names on Ebay like Epiplan, Primo, LOMO. But I don't know what they mean. I don't even know if Zeiss even made 4X objective for my standard. Can a Zeiss maestro teach me what I need? I'd also love to hear from anybody who would like to sell their 4X, assuming they exist.

Thanks so much, Keith.

[PeteM]

No Zeiss Maestro here, but I've seen lots of 2.5x and 6.3x finite Zeiss objectives, but don't recalling seeing a 4x. The 2.5x offers a very nice wide view and might suit your needs. You could use higher powered eyepieces or a mag changer with it as well.

Zeiss is also somewhat unique in supporting DIC all the way down to 6.3x (many other finite brands/models stop at 10x or even 20x).

[BramHuntingNematodes]

The plan 2.5x 160mm is a good lens. I have it on a little field scope and it's.quite.sharp. A bit low for.diatom picking though.

[Sabatini]

I have the opportunity to use the Zeiss 6*5 phv in conjunction with the Leitz Heine condenser and although it does not cover the entire field of view it is a very nice and fun objetive with very clear and contrasting images.....lts a very interesting objetive

[Sabatini]

Now I have a question and that is which phase contrast condenser cover the intare fov of this objetive...y

[Hobbyst46]

Not an expert here.
The Zeiss Optical Systems catalog shows that Zeiss made a 4x0.16 Planapochromat, 2.5mm working distance. Never seen or used one, but there are potential points against it for your case:
1. Short WD
2. Possible delamination
3. High price
I agree with PeteM and Bram about the 2.5x. For diatom picking, I would also find it a little bit too weak.
I pick diatoms on a stereo microscope, usually magnifications of 60-80x. I align the "mechanical finger" under 10-40x.

On a much higher level: AFAIK, the late great master Klaus Kemp picked diatoms with a LOMO compound microscope,
and a 10x objective, perhaps the 10x Lomo objective has a long WD.

Back to earth: a couple of years ago I purchased and tried a no-name Chinese 4x0.10 Planachromat for ~17 $. Of course, on the Zeiss it produced noticeable aberrations (mainly chromatic). An inexpensive 4x Nikon E achromat performed better. I can try and find the working distances of those objectives. Neither of those two was parfocal with other Zeiss objectives though.

EDIT: That no-name 4x objective is marked "0.17" so designed for use with a coverslip, again not so good for diatom picking...

One more point: Zeiss also made a simple short-barrel achromat 3.2x objective which I did not like, can't remember why... no parfocality I guess.

[MichaelG.]

I need some help. I need a 4X objective for my Zeiss Standard model 18 scope. I need an achromat, […]

I have a Zeiss PlanApo 4x / 0.14 which is one of my favourite objectives

46 02 40-9903

… probably extravagant for your stated purpose, but definitely worth grabbing if you ever see one at a reasonable price

[ noting, of course, the potential for delamination problems ]

MichaelG.

[Phill Brown]

There are a couple Watson 4x .13 on eBay.
Marked as Para and intended to be parfocal on the microsystem 70, which they are not.
Easy to clean and service.
RMS 160.
Good working distance.
I have 2 Nikon 4x also but they are not optically better.
Not had delamination on any Watson objective yet.

[keithstout]

Thanks, folks. Any low mag from 2.5-4X would work. I was hoping to get a low mag parfocal achromat that had a short barrel, affording plenty of working distance. When setting up for diatom picking, I need to skillfully position my glass needle over the slide and in the optical path with the diatoms. The low mag lets me quickly find the needle tip and get it in place. The generous working distance lets me move around the needle without breaking it. It's much more difficult to do with the 10X, and I'm breaking needles.Once I get my needle in place with the low mag, I switch to the 10X objective and pick diatoms there.

I am currently picking diatoms on my Leitz BK, which has a 3.5 achromat. I pick and arrange with the Leitz and enjoy the view with my Zeiss phase contrast. But I'd like to move the picking/arrangement operation to the Zeiss, which can do everything the Leitz can. The Zeiss has superior X,Y stage movements; that's what I'm after.

I have seen some Zeiss plan and planapo 2.5X, but the objective barrels look pretty long, reducing the working distance. I could be fooled by the photos. I sent some requests to the sellers to measure the barrel length, but no response yet.

[keithstout]

Oh, hey. I can't believe I didn't think to ask. Can somebody measure the barrel length in mm of the Zeiss 2.5X plan objective for me? Do not include the threads in the measurement. I'd like to know the barrel length of the 2.5X plan apo as well. I'd be so grateful. Thank you.

[Hobbyst46]

Thanks, folks. Any low mag from 2.5-4X would work. I was hoping to get a low mag parfocal achromat that had a short barrel, affording plenty of working distance. When setting up for diatom picking, I need to skillfully position my glass needle over the slide and in the optical path with the diatoms. The low mag lets me quickly find the needle tip and get it in place. The generous working distance lets me move around the needle without breaking it. It's much more difficult to do with the 10X, and I'm breaking needles.Once I get my needle in place with the low mag, I switch to the 10X objective and pick diatoms there.

I am currently picking diatoms on my Leitz BK, which has a 3.5 achromat. I pick and arrange with the Leitz and enjoy the view with my Zeiss phase contrast. But I'd like to move the picking/arrangement operation to the Zeiss, which can do everything the Leitz can. The Zeiss has superior X,Y stage movements; that's what I'm after.

I have seen some Zeiss plan and planapo 2.5X, but the objective barrels look pretty long, reducing the working distance. I could be fooled by the photos. I sent some requests to the sellers to measure the barrel length, but no response yet.

The barrel length of the Zeiss Planachro 2.5x is 35mm (excluding the thread of course). Its WD is 8.7mm.
The barrel length of the Zeiss Planachro 6.3x is 44mm (excluding the thread of course). Its WD is 4.9mm. Almost the same
as the WD of the 10x0.22 unfortunately.
Interestingly however, both the plain Zeiss 6.3x achromat and the Zeiss 6.3x neofluar have WDs of 10.3 and 10.8mm, respectively !and both will very likely be parfocal with the 10x.
I once owned an Olympus SPlan 10x0.30 objective, a great objective with a relatively long WD of ~7.5mm, but again it was not exactly parfocal with the other Zeiss objectives.
In terms of WD, nothing matches a stereo; since the vertical movement range of the tip of my picking "mechanical finger"
is ~30mm, I leave it attached to the (very old) microscope base all the time; and place a protecting flat "table" over it, so the objective can be raised further, and any specimen that is not related to diatom picking can be placed on the table and observed, while the mechanical finger is kept safe and sound below the surface of the table.

EDIT: note that there are at least two slightly different barrel forms of the Plan 2.5x/0.08.

[Hobbyst46]

Just one more thought. To fill the FOV of the 2.5x with light, the condenser must be removed (at least so it is with my phase contrast turret condenser). To use the 10x (especially if phase contrast), a condenser must be installed and aligned.

[keithstout]

Thank you so much hobbyst46. This is very valuable information for me. The 2.5X plan achro is exactly what I need.

On my Leitz, the 3.5x achro barrel is very short, like a snub nosed .38 is to a rifle barrel. I can drive a truck through its working distance. The Zeiss objectives are quite different, I see. Nevertheless, the 2.5X plan will give me the elbow room I need. What a relief. You folks are so great.

[Scarodactyl]

Any particular reason not to move the leitz objective over to the zeiss?

[keithstout]

Yeah, I tried that, but it didn't work. I couldn't get the image to focus despite racking out the focus knob.

[keithstout]

Just smashing!!! I scooped up a 2.5X plan and got it on my Zeiss Standard minutes ago. It's gorgeous. It's physically twice as long than I'd like it to be. I have be very careful where I position my diatom picking needle so the 2.5 doesn't bump it. But it's manageable. The added working distance was exactly what I needed and made all the difference. The black half of the optic is a hidden benefit, though it doesn't match my other Neofluar objectives in appearance. It serves as a handy indicator for objective selection. When I see the black at the 6:00 turret position, I know it's safe to position my needle into the optical path.
I couldn't have done it without your help, guys. A big thank you to everybody.
Keith

[keithstout]

The new Zeiss 2.5X objective is really great. It has allowed me to move my diatom picking and arranging operation to the Standard 18. Thanks again to all who chipped in their two cents. Keith.

[Hobbyst46]

The new Zeiss 2.5X objective is really great. It has allowed me to move my diatom picking and arranging operation to the Standard 18. Thanks again to all who chipped in their two cents. Keith.

Great !

[MicroBob]

Hi Keith,
a good and very short objective that fits well to your Zeiss West Standard would be the Leitz EF 4. It is shorter than the Zeiss Plan 2,5.
You might already be aware of this but there were two Zeiss companies between 1945 and 1990: Zeiss Jena and Zeiss West (Oberkochen and Göttingen). There are certain compatabilities but in general they have to be kept apart. Leitz 170 and 160mm tube lenght objectives with 45mm parfocality fit well to a Zeiss (West) Standard. But only eyepieces with stated field number like 10x18 will fit well.

Bob

[keithstout]

Thanks for the Leitz objective tip, Bob. But I already bought Zeiss' 2.5X Plan. It gives me just enough elbow room to get my needle in position. I looked it up and the Leitz would indeed give me more working room. I'll file this info away in case my needs change. I really appreciate it. My eyepieces are KPL W 10X goggle. Will they work with the Leitz EF?

[Adam Long]

I have the Zeiss 2.5x (modern version), the 6.3x Neofluar and the 4x Planapo (older version).

The 6.3x NF has by far the most working distance, and unlike the 2.5x the objective is tapered which gives even more room. The older 2.5x looks a little narrower than mine, but not as much as the 6.3x. I would look out for one of these NFs, it is one of my favourites. It also seems that Zeiss matched the illuminated circle of their 0.9 condensers to the 6.3x field of view.

My 4x Planapo has very little working distance - less than a typical 10x - but I have seen pictures of a newer version that looks more like the 6.3x NF, like this one on ebay: https://www.ebay.co.uk/itm/204072542518 - I would like to upgrade but not at that price.