Phase contrast for a Microstar

What equipment do you use? Post pictures and descriptions of your microscope(s) here!
Post Reply
Message
Author
Plasmid
Posts: 10
Joined: Mon Sep 28, 2020 5:34 am
Location: United States

Phase contrast for a Microstar

#1 Post by Plasmid » Thu Oct 01, 2020 3:01 pm

Hello, Im very new to microscopy and so would like to know what would be the best way to dive into phase constrast with my current set up. I purchased a Microstart IV with a broken focus cam... Apparently something that is very common for this scope, I found the broken pieces at the bottom, glued them back in place and sand them and I'm getting very smooth transition during the focus. Would that being said I would like to jump into face contrast microscopy and I know there is multiple ways to do so, what would be the easiest way since most of parts for the microstar are rare?
Thank you
A Bacterial Plasmid

apochronaut
Posts: 3539
Joined: Fri May 15, 2015 12:15 am

Re: Phase contrast for a Microstar

#2 Post by apochronaut » Thu Oct 01, 2020 5:02 pm

I wouldn't describe the parts for a Microstar IV as rare, just maybe as , well utilized. The optical quality of the series is still within range of what would be called excellent, so many examples of the Microscope are still in use . It would be hard for many labs or institutions to upgrade from one without spending a bundle, and it seems to be increasingly recognized that the Microstar IV and Diastar are THE deals in picking up a used microscope.
Member wabutter apparently has, or recently had a phase system available if someone has picked it up. If that fails, I have most of a system. The condenser sans any diaphragms, and a set of the 3 Neoplans, they made; 10, 40 and 100. I may have a 20X planachro too but I have to check it over.
The diaphragms are available from some dealers who formerly sold AO.

PeteM
Posts: 1234
Joined: Tue Dec 06, 2016 6:22 am
Location: N. California

Re: Phase contrast for a Microstar

#3 Post by PeteM » Thu Oct 01, 2020 6:04 pm

Congratulations on the focus cam repair - that's more than most are willing to take on.

If you happen to have machining capability, I've had some luck re-machining Series 10,20,110,120 condensers to fit the 410,420 series. Phil might know if the annuli are still a good match. My recollection is that they work, as long as the LWD (long working distance) types aren't in the mix.

With patience the right set will come along; though perhaps married to a complete scope. Like trinocular heads, more and more hobbyists want phase contrast and the prices seem to be inching up. But there are still deals to be had.

If you don't have simple polarization, that's something that can provide some contrast (and open up another world of viewing petrographic samples, fibers, chemical crystals, etc.). That's easier and cheaper to find (or make) and fit. As little as $30 for a couple camera polarizers; one for the field aperture and one to insert under the head. Likely under $100 to find the OEM intermediate analyzer piece or (with a 3D printer) make one as shown in a recent and ingenious post here.
Last edited by PeteM on Thu Oct 01, 2020 6:18 pm, edited 1 time in total.

Plasmid
Posts: 10
Joined: Mon Sep 28, 2020 5:34 am
Location: United States

Re: Phase contrast for a Microstar

#4 Post by Plasmid » Thu Oct 01, 2020 6:15 pm

Thats encouraging, do you happen to know or recommend some of the sites or stores where said extras can be purchased? So far I purchased a Abbe 0.9 1201 condenser from ebay to replace the 1970 abbe 1.25 that came with my Microstar, since the 1201 has a slot for darkfield filters. To be honest ebay is a hit or miss, the first used Microscope I bought from ebay a Carlsam CS700 arrived with the plastic tray where the electronics are held completely destroyed.
Question, mine came with 4 objectives 4,10,40 and 100 oil. The markings have worn out with time i guess, but it appears to be Neoplan from what i gathered, Im looking to add a (50x Reichert) or a dry 60x , the 60x being the preferable choice being a dry objective, which brand is compatible with the ones I have already to maintain parfocality? Does it have to be neoplan, infinity, achro?

PeteM
Posts: 1234
Joined: Tue Dec 06, 2016 6:22 am
Location: N. California

Re: Phase contrast for a Microstar

#5 Post by PeteM » Thu Oct 01, 2020 6:21 pm

Plan achro is likely the best you'll find. Neoplan a slight step below. Plain achro (no "plan") meant for lower end scopes. Higher end versions are very rare; though I've had some Reichert branded infinity objectives in 40x and 100x and with higher numerical apertures (likely some fluorite glass) that look very good.

The 50x plan oil iris objectives are very good - and suitable for darkfield as well. I'm not aware of an OEM 60x dry objective for the Series 410 -- and generally don't recommend them. The image will be so much better with the 50x plan oil (or 100x plan oil) objective, it's worth the minor annoyance to use immersion oil.

I'd look for a 20x plan achro long barrel AO/Reichert/Cambridge/Leica objective to fit your scope. It's an excellent objective in a very useful magnification.

Plasmid
Posts: 10
Joined: Mon Sep 28, 2020 5:34 am
Location: United States

Re: Phase contrast for a Microstar

#6 Post by Plasmid » Thu Oct 01, 2020 6:26 pm

Thabk you .Some JB weld then sanding using a dremel and finally fine grid by hand, all done without disassembly.Had to make sure to mask and cover the parts below. One day I hope to take it apart and replace the cam itself, but theres very little info out there on how to take apart the fine and coarse focus. Anyone ever taken one of those apart?
Attachments
From what I gather this is very common righ?, I'm guessing you usually happens when people lift or try to move the microscope not realizing that the objective assembly is the one that moves and not the stage.
From what I gather this is very common righ?, I'm guessing you usually happens when people lift or try to move the microscope not realizing that the objective assembly is the one that moves and not the stage.
IMG_20200924_144007046.jpg (98.77 KiB) Viewed 267 times

PeteM
Posts: 1234
Joined: Tue Dec 06, 2016 6:22 am
Location: N. California

Re: Phase contrast for a Microstar

#7 Post by PeteM » Thu Oct 01, 2020 6:28 pm

I've described the same repair as well. Glad you took the time to take a picture. It's a hassle to get the cam out, so an in situ repair can make good sense - with the precautions against dust taken.

If it's still rough at the point of close focus, you may be able to adjust the stage height one way or the other to move the final focus to a different part of the cam.

jjcook
Posts: 30
Joined: Wed Jul 29, 2020 4:23 am
Location: Portland, OR, USA

Re: Phase contrast for a Microstar

#8 Post by jjcook » Thu Oct 01, 2020 11:00 pm

Plasmid wrote:
Thu Oct 01, 2020 6:26 pm
Thabk you .Some JB weld then sanding using a dremel and finally fine grid by hand, all done without disassembly.Had to make sure to mask and cover the parts below. One day I hope to take it apart and replace the cam itself, but theres very little info out there on how to take apart the fine and coarse focus. Anyone ever taken one of those apart?
I just took apart the fine and coarse focus on my Diastar to repair a coarse focus issue, you can find my thread here: viewtopic.php?f=5&t=10490
- Jeff

apochronaut
Posts: 3539
Joined: Fri May 15, 2015 12:15 am

Re: Phase contrast for a Microstar

#9 Post by apochronaut » Fri Oct 02, 2020 1:24 am

Plasmid wrote:
Thu Oct 01, 2020 6:15 pm
Thats encouraging, do you happen to know or recommend some of the sites or stores where said extras can be purchased? So far I purchased a Abbe 0.9 1201 condenser from ebay to replace the 1970 abbe 1.25 that came with my Microstar, since the 1201 has a slot for darkfield filters. To be honest ebay is a hit or miss, the first used Microscope I bought from ebay a Carlsam CS700 arrived with the plastic tray where the electronics are held completely destroyed.
Question, mine came with 4 objectives 4,10,40 and 100 oil. The markings have worn out with time i guess, but it appears to be Neoplan from what i gathered, Im looking to add a (50x Reichert) or a dry 60x , the 60x being the preferable choice being a dry objective, which brand is compatible with the ones I have already to maintain parfocality? Does it have to be neoplan, infinity, achro?
The 1970 is actually an abbe aspheric and it is a wide field condenser too. For covering the field of a broad range of objective's, it is slightly superior to the 1201. It also offers the possibility of oil immersion to maxmize the potential of oil immersion objectives. The filter carrier is a separate device from the condenser body and is added onto the bottom of it. A 1970 condenser is just as likely to have one as the 1201.
There is no 50X planachro oil objective for the series 400. There is a 50X .80 oil immersion Neoplan, however. You may find it cumbersome to use, if you idealize a higher power dry objective but it does do nicely as a support objective to a100X oil immersion.
There are 60X .80 dry infinity corrected objectives from China that will work well in a Microstar IV. Around 80.00. They are just o.k., and the contrast is a little low.
Best bet is to get a pair of cat. # 182 15X eyepieces. They will essentially add a 6X, 15X and 60X objective to your system. If you can find a 20X .50 planachro as Pete mentioned, to add to your system , you would also be adding a 30X objective. All those objectives can handle the extra 5X from the eyepiece.
To refine your 60X dry magnification further, a 40X .70 planfluor would be an improvement .

Plasmid
Posts: 10
Joined: Mon Sep 28, 2020 5:34 am
Location: United States

Re: Phase contrast for a Microstar

#10 Post by Plasmid » Fri Oct 02, 2020 3:36 am

@Apochronaut, when you say that the 1970 could be used with oil immersion, does that mean oil on top of the condenser below the slide or just objective immersion with the 100x?

Zuul
Posts: 212
Joined: Fri May 01, 2020 9:01 pm
Location: California

Re: Phase contrast for a Microstar

#11 Post by Zuul » Fri Oct 02, 2020 5:55 am

Plasmid wrote:
Fri Oct 02, 2020 3:36 am
@Apochronaut, when you say that the 1970 could be used with oil immersion, does that mean oil on top of the condenser below the slide or just objective immersion with the 100x?
It means oil between the condenser and the bottom of the slide. You cannot achieve the maximum n.a. of an oil objective without the oiling the condenser, too.

hans
Posts: 327
Joined: Thu May 28, 2020 11:10 pm
Location: Southern California

Re: Phase contrast for a Microstar

#12 Post by hans » Fri Oct 02, 2020 4:29 pm

apochronaut wrote:
Thu Oct 01, 2020 5:02 pm
The diaphragms are available from some dealers who formerly sold AO.
What is dealer pricing like for individual diaphragms?

Post Reply