How sensitive are objectives to slide or stage crashes?

[snik]

I came across an affordable Leica 100x/1.30 PL Fluotar, but the front has a lot of scratch marks from collisions. What are the chances that the optics are compromised? I don't think this objective has a spring loaded core.

Another question is whether this is a good upgrade from my 100x C Plan PH3. I don't have a trinocular, so for now I just use my scope for direct observation. More contrast and less distortion would be nice, and one day I'll get a trinocular for sure.

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[PeteM]

Good 100x lenses are often designed with some protection for the central portion of the glass. With oil immersion, a 100x may yield an OK image with a slight scratch. Yours, however, was repeatedly entered into a demolition derby. In addition to scratches, there's a good chance the oil seal has been compromised. Personally, I wonder about the mental competence and care of whoever was using it.

However much you would like a bargain, this probably isn't it. It sounds like you already have a perfectly serviceable 100x. Instead of a trinocular head, for now you can use a cell phone camera, a holder, and a spare eyepiece to take images. If you don't already have a phase condenser, you may likely have the type of Leica condenser that can insert a single phase ring - making full use of the 100x objective you have.

FWIW, most Leica 100x Pl Fluotar objectives have the entire front end retracting - there's a large shroud - and it doesn't look like the typical 100x where only a central portion retracts.

[apochronaut]

It is hard to see how that degree of abrasion and scoring over such a wide area could take place as a result of contact with a glass cover slip, especially when lubricated with oil. That looks like it is damage caused by something harder than the metals used for the front bezel and lens mount.
Sometimes, when there is an odd mix of objective lengths, the longer objective can hit the stage or slide carrier components with careless rotation or is it possible that objective was used for metallurgical samples?
I would beware of that one unless it is under 150.00 and it is absolutely clear that it can be returned if it under performs, no questions asked.

[snik]

Thanks for the input guys. There seller accepts returns, but with $100 shipping both ways I'll pass on this one.

My 100x is in good condition, and I do have a phase slider for it. One thing I've found though is that I prefer staining specimens instead of using phase contrast, and comparing a 40x phase with a 40x non-phase, I see there's a reduction in BF contrast with the phase objective. I'm using a phone for photos at the moment. It's a bit of a hassle setting up inbetween viewing and images are noticeably worse than what I see with my eyes.

[apochronaut]

Returns are getting trickier but an objective that doesn't achieve a level of performance that matches the description is supposed to be returnable on the sellers coin. They have to send you a trackable shipping label : if that is an ebay purchase?

Here is my worst ebay return experience for general into. It does show that the system works in the face of seller manipulation.

I bought a 40X planapo a while ago described as fully functional and works as intended. Seemed like a good bet, since I had already bought one that didn't and the seller was very good about it and issued a refund, not even expecting a return. What's the point?
Well this one didn't work either. You could see through the objective clearly with your eye but the image through it was very low contrast and foggy, with some ca. The seller insisted that the optics were clear when he shipped it and that I had just changed my mind or had dropped it and damaged it. It seems he might not have ever looked through it, just had gone by the clarity looking at a window through it with his eye but the rear setting ring had scratches ; evidence of prior disassembly. Under examination with a stereo microscope , I could see slight de-lamination internally.
I took photos of it and through it , as well as through a different 40X planapo up to spec.and included images of the scratches on the setting ring. The seller claimed that my photos were doctored or fake and that I had made those scratches disassembling it myself and he fought like crazy to not have to accept a return. He knew he was paying to receive back trash. He finally issued a label, just before a weekend extended holiday but immediately cancelled it, saying it was the wrong one, attempting to stall on issuing another to eke out time until it was too late to return it because there was a timeframe and a certain amount of it was already gone. Ultimately, ebay stepped in and issued me the refund. I guess they will extract it from his account.
The sad thing is : I already had a poor version of that objective and was going to suggest to the seller that I attempt to make one out of the two and if successfull I would cancel the return and he could keep his 150.00. I would have been content with that and he seemed a bit desperate. However, when the antics started and continued, I avoided anything that might resemble me tampering with it, especially since he tried to claim that the disassembly marks had been caused by me. It seemed to escape him that the suggestion of that was an admission that the objective was defective.
Ultimately, I did make 1 planapo objective out of the two and it cost $0 : just 1 1/2 hours of time. I have considered sending him some money but I'm not feeling too generous right now.
Although ebay is having problems and clearly trying to keep their merchant base, they still do honour their buyer protection policies if all the ducks are in a row. That is the key. In this case, it was described as works as intended. That is one key. I wouldn't have bought it otherwise. The other key is, providing good photographic documentation for the return. It doesn't matter if , as was the case here, the seller says they won't accept returns. That is only if you want to return the item for a reason other than if it doesn't match the description. The seller is obliged to accept a return if the item does not match the description.

[PeteM]

A way to eliminate most of the hassle with a cell phone as a microscope camera is to buy or use a spare phone. For example, you can buy a new-old-stock iPhone 6 for around $60 on eBay, a holder for about $20, a remote release for about $15, and a third properly corrected Leica eyepiece for perhaps $55. $150 total even if you don't have a spare earlier generation phone. Having the dedicated phone eliminates the hassle of lining things up each time.

Once you have the phone clamped to the eyepiece, you have a fully corrected system that only requires a couple seconds to take out one eyepiece and insert the camera-connected eyepiece.

If your microscope requires eyepiece corrections - and the Leica infinity ones do - a regular cheap (say $500 USB camera) has three problems regardless of whether it's sitting on a binocular or trinocular tube. First, the 2x relay optics to get the right size image are mediocre. Second, it doesn't have corrections. Third, the sensor quality is often poorer than the cell phone camera you may already have or can buy at a fraction of the cost.

You can run your microscope-specific cell phone on WiFi - saving pictures as you go - with no need for a second phone plan.

It's somewhat counter-intuitive but you don't need super high pixel counts to resolve higher magnification. The size and quality of those pixels often matters more. USB, HDMI, and some C-mount microscope cameras toward the lower end often have many millions of tiny, crappy pixels in their small sensor sizes - and if USB 2.0 no way or recording them fast enough for satisfactory videos. Even an older version cell phone will often have a higher quality sensor - and of a lens size that matches well to afocal viewing through a corrected eyepiece - and with a zoom function to match images sizes.

It's also worth noting that most everyone finds that the image they see through the eyepieces is better than they record with a camera - even a $300 (to $3000) mirrorless full frame or APS-C camera body sitting on top of a $500 trinocular head. It's a perennial unhappy surprise as we add cameras to microscopes. There are several reasons for this:

- binocular vision gives a sort of immersive effect
- our eyes' rods and cones have an incredible dynamic and color range
- specimens are typically too thick and rarely fully in focus at higher magnifications - a camera can only pick one focus point at a time while our eyes dynamically adjust focus somewhat as we peer through a microscope
- other issues of eyepiece corrections, relay lens quality, matching image sizes, shutter shake, and vibration

The main way to get spectacular still photo images is to use focus stacking in a setup with carefully prepared specimens, proper corrections, good optics from top to bottom, and all sources of vibration eliminated as nearly as possible. You may find you can get a long way down that path with the equipment at hand.

As you know, the phase ring does rob a small fraction of ultimate resolution and contrast. The plus, of course, is that it adds contrast for somewhat transparent living cells. However, it may be that careful setting of Kohler illumination and centering and adjustment of the field and condenser irises will improve contrast. In general, Leica infinite objectives have excellent contrast. If you eventually get a better 100x, you might consider one with an iris to allow darkfield imaging.

[apochronaut]

That is a very good synopsis. To add about phase annuli. The visual effect that occurs when phase objectives are used for BF seems like a loss of contrast and very slightly resolution. The annuli cause phase retardation in either the area of the annulus or it's surround depending on whether the objective is positive phase or negative phase. This causes a small but noticeable amount of spherical aberration. A similar effect can be produced by using an off spec. cover slip thickness.

[snik]

That's a horrible experience apo, sorry man. I didn't know the seller would pay for returns. The seller of this objective sent me that picture on request since the image in the listing was blurry. Seller also stated via messaging that "it's all good" and he would accept returns, but this is not stated in the listing. I wonder if I have the same protection from ebay based on messages.. The listing only says "used condition".

Regarding spherical aberration, I guess I can get measurements that are slightly off across the frame. Is that correct? I've used a calibration slide and calculated µm/pixels over the horizontal central portion of the image.

The phone setup I have is not half bad. I printed a holder that the phone slides into, and it's a tight fit around one eyepiece while resting on the other.

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This phone has two wide-angle sensors; wide and ultra wide. I have to do a 2x digital zoom to get a tight square crop. Then I set manual focus, same distance as used for calibration, and tweak exposure. The app (Halide) remembers the last settings, so it's not that bad altogether. It spits out 12mp images, but I can resize to 2mp and not loose any detail.

The explanation for why binocular viewing is so much better makes a lot of sense, especially that part about eyes adjusting continuously. I just figured a camera on a trinocular would be vastly better. Fitting a given camera to a microscope is also daunting in itself - seems like manufacturers really didn't want to make it easy. Leica has this MPS32 system that ends up on 35mm film, with a 10x photo ocular (I think), possibly with a 0.32x converter.. Not quite sure.

So yeah, for now I'm stuck with a phone, and the only upgrade I have in mind is a 3-sensor iphone with a longer focal length. I just bought a cheap wireless bluetooth trigger, which is nice to limit vibrations. I also have an idea about hooking it up to an arduino timer to make timelapse videos. Automatic photo stacking could be cool as well, but manually turning the focus isn't that hard..

[apochronaut]

Whether the seller has to bear the cost of shipping is entirely based on how the item is described. Used condition is pretty vague because there is no condition report. What you really want to see are words like fully functional, works as intended etc If there is a dispute , ebay will read correspondence and weigh it as much as the listing info. but the listing must give you a reason to expect that the objective works up to spec.