Need Advice on Checking Stylus

Would appreciate some advice on how to check the condition of a stylus. My primary cartridges are the Soundsmith Zephyr and the Lyra Delos. I just bought a vintage pocket stylus magnifer (50x) for a couple of bucks. Ok, so what now?? I assume I'll need a good light source. Is a penlight flashlight enough, or shouold I buy something else?

Ok, when I get the proper light source and my stylus magnifer is delivered, what am I looking for? How can I estimate sylus condition and wear?? As I recall, the Zephyr has an elliptical stylus. The Delos is a micro-ridge contact line -- I think.

I would start by looking online at the thousands of good pictures of magnified stylus and get familiar with what the different tips look like in various conditions. Your 50x should serve you well in any preliminary examination.
Check out this video of Wally Malewicz showing and explaining cartridge wear.
I think at 50x you will not be able to come to any conclusions about your stylus, unless it is just plain broken. I have a digital microscope, cheap one, which goes up to 800x, and I use it for SRA. As far as determining wear, even at 800x, it is very hard to say conclusively that you do, or do not have wear. The best angle for wear determination is straight on, but even then, you have to know how much of the stylus is actually in the groove, and then what wear actually looks like at that magnification. I believe we are talking a out very subtle differences in the image, even at 800x. I don't think you stand a chance at 50x.
I own this Colton x 50 hand microscope and need to try for at least a half hour to get the stylus in focus. I was never able to conclude anything from what I have seen or,
better, not seen. So why I still use the thing? Well why many people burn candles in the church? Those are a kind of analog rituals. Then consider this: "you don't own even a hand microscope????''
Uuuhhmm. Captain.. and Nandric. I read your posts and get the point (pun).

The way I see it is that stylus wear occurs slowly over time. Therefore, to simply say, use your ears to tell you that if the highs become muddy, or the bass does this or that, then you know it's time to change out the stylus. Interestingly, Peter Ledermann has reported that my Zephyr stylus is x% worn and needs to be retipped, or not ... as the case may be. It would seem he has the right equipment, plus extensive experience to make such calls.

I guess that leaves me no better off than when I started this inquiry. Perhaps the 50x magnifier may have limited utility if it will tell me whether the sylus is badly chipped or worn. Other than that, perhaps the next best option is to run my #1 cartridge out for 1000 to 1500 hours, then send it to Peter Ledermann for a check. While #1 is out of commission, I'll use my #2 cartridge.

Other than that, I don't know what else to do. To wait for black vinyl shavings to peel off the records tracks to alert me that the stylus is shot is ridiculous.
I think it is worth, it is great seeing the different stylus designs at 800x. Plus with experience you might be able to detect wear. You can get a cheap digital microscope, like mine, for around $60, but you get what you page for. Getting it focused is painful, because the base is poor quality, also the software is not that great. USB interface that does stills and video. Also great for seeing how clean your stylus is and the results of cleaning it, also results after playing a dirty record. At 800x you can also look at the grooves of a record before and after cleaning to see the results. Great fun. I actually suggest you get one, but it should be a minimum of 400x and if you can splurge for the ones with a better base, it will be much easier to use.
Fremer in his review of the Anna cartridge wrote that a worn-out [extreme contact] stylus should do no damage to the vinyl unless it's chipped. His logic was that a typical wear of the stylus simply makes it duller, not sharper. I've always wondered about this. Has there actually been a study to show this damage we audiophiles are taught to fear so much?
I use a USB digital scope which magnifies up to 750x. I took a picture of my stylus when new and now I take a picture every 6 months and compare it to the "new reference". If you are patient, you can overlay the two images for comparison purposes.
I do not replace a cartridge until I notice the high frequencies start to "droop" and details in the music diminish .

A worn out stylus has rounded edges, and does not damage the groove, like a new misaligned cartridge would. Michail Fremer is right.