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 Replies: 8 / Views: 2,106 |
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New Member
United States
25 Posts |
So I searched this forum for any hits on the ZipScope from Aven and came up empty. So here goes. I just got one in the mail today with much anticipation. At $72.00 I didn't expect the world, but was fairly disappointed with it's performance for coin inspection and photography. It's a good microscope, but has one or two fatal flaws that maybe someone can help me with. One in particular that I can't seem to fix with different free software's I've tried (Debut & ProScope HR).
The ZipScope has 8 LEDs that can be adjusted to high and low settings (low is plenty). Working in a dark room, with the LEDs set on the low setting, the images were great in terms overall clarity, especially at the higher resolutions. However, the lighting was not uniform across the viewing field. More specifically, there's a "hot spot" in the center of the field. So when viewing a coin, even a low-luster copper penny, the center of the image is washed-out. It reminded me of what I'll call camera "flash-back" when taking flash photography of a reflective object (e.g. window). I can still inspect coins by working around the perimeter of the viewing field, but if I want to capture a picture of the entire coin, forget it. The center of the coin is just too overexposed. Using the ProScope HR software I can adjust the brightness. But even at the lowest setting, the affect is still there.
Is this a white balancing issue? The ZipScope is said to have an "internal" white balancing feature, whatever that means. I have lots of experience with high-end microscopes, and any white balancing feature I've used requires setting the white balance against the background, then moving your specimen into field. So whatever white balancing feature the ZipScope has, it's invisible to me.
I've tried all colors of background, external lighting, angle shots, etc. but just can't fix this problem without creating a new one. I was thinking of crafting a filter to try to balance the LED lighting. But it would have to be a MacGyver-type filter crafted out of colored plastic or mylar film, the color of which I would have to experiment. Some shade of grey-blue I suspect.
Any suggestions how to balance out the LED lighting short of purchasing high-end software would be greatly appreciated.
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Pillar of the Community
United States
7840 Posts |
I have not heard of a "ZipScope". There is usually lots of traffic on this section and someone with an inkling of a clue should be along anytime.
Success,
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New Member
 United States
25 Posts |
Thanks. I've been doing some more reading and white balance is not the issue. Apparently, USB digital microscopes like the ZipScope that have LEDs mounted around the circumference of the lens are notorious for causing lighting hot spots, and diffusing the light is the only way to fix the problem. One contributing author on ebay suggested using an external light source, or better yet a diffuser to scatter the LED light so it's not so pin-point. Searching the internet I found some "professional" diffusing materials that you can buy, but they are pricy and much larger than what I need. If I took this route, I'd have to "customize" a piece so that there is a hole in the middle so as not to block the lens. Not a problem, but again the MacGyver thing. He also suggested the material that plastic milk jugs are made of can work. Much cheaper. I might give that a try. Maybe someone else has some other ideas, or knows of a product (e.g. external light source) or diffuser that I can purchase on-line. Cheers |
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Moderator
 United States
23522 Posts |
The MacGyver thing is half the fun of coin photography.  Whit balance is not an issue because the manufacturer knows the color temperature of the lighting. That makes the adjustment easy. External lighting is a possibility - I'll recommend the usual Jansjo LED goosenecks for that application as they're infinitely adjustable for position and angle - but unless you've got ~100mm of relief from the subject, any external lighting is going to be problematic. The beauty of the McGyver solution (vellum is the weapon of choice for diffusion) is that you can tailor it exactly to the size and diameter of your specific LED's. In conjunction with tape, it becomes part of the microscope so you have nothing external to complicate your shot. Either of those choices will have a bearing on white balance, especially external lighting, so you might have to correct in postprocessing. |
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New Member
United States
25 Posts |
I'll definitely look into the Jansjo LED goosenecks; is one sufficient, or would it be better to use two coming in at opposing angles (to help make illumination more uniform). I'll also check out vellum. At first I thought you said valium, to calm my nerves trying to get the best solution. :) Thanks for the suggestions. I guess it's going to be a matter of trial and error, until I achieve the "look" I'm looking for. Cheers.
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New Member
United States
25 Posts |
Post Note: So maybe the title of the post shouldn't include "thumbs down" for the ZipScope because I think this is an issue with all low end USB microscopes. It actually is a very nice scope. Also, if you get this scope or any other, plan on purchasing a more solid stand. The ZipScope has one that custom made for that product, but I think can be used with just about any of the similar scopes out there. I think there's made by the same Chinese manufacturer! The stand that comes with the ZipScope is quite frankly a joke. It's made of nice, solid materials, and has a cool shiny color tone, but it's as wobbly as my legs after a few cold ones. :) So plan on tacking on another $40-$50 USD to your purchase.
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Pillar of the Community
United States
4038 Posts |
This thread is useless without pictures.
For diffusion, I recommend Canson Opalux, about $4 per 14"x24" sheet.
Contact me for photographic equipment or visit my home page at: http://macrocoins.com |
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Moderator
United States
23522 Posts |
If you're near an Ikea, you can get the Jansjos for $10 apiece. If not, Amazon has them for $18.25 with free shipping. How many you'll use kind of depends on what you're shooting. For details at high magnification, I generally shoot with one lamp at a pretty low oblique angle - tends to highlight the "steps" of doubling & such - occasionally with a second mounted high and straight down for full-field illumination. |
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Pillar of the Community
United States
1126 Posts |
 Yep, Best way to get around the glare and hot spot issue caused by the built in LEDs, is just shut the LEDs off and use external LED lighting.. or try a combination of both. Get the Jansjo's or any oether type of adjustable goose neck LED lamp. I picked one up at Staples for $19 it now doubles as my desk lamp  |
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Posted 10/04/2012 12:56 pm
