USB Hand-held microscopes cost less than $200 but turn out very useful in all those cases where you cannot take samples to put under a compound microscope. A USB microscope is essentially a macro lens, the magnification is restricted and is not comparable to a standard compound light microscope but features such as grain size for mineral pigments and retouches crossing craquelure can be documented. I blog here on the images I took using a Veho VMS 2 Mega pixel.
Hand Held microscope Veho VMS 2 Mega pixel. I used this microscope for the images presented in this blog.
Calibration. I strongly suggest to buy a Stage Micrometer Calibration Slide. You find it on eBay for about $30. They are mandatory in order to calibrate your microscope so that you know exactly the size of what you are measuring. They have divisions up to 0.01 mm so that you can calibrate your microscope until 10 microns.
Stage Micrometer Calibration Slide with 0,01 mm (10 microns) divisions.Veho VMS has two magnifications. Looking at the Calibration Slide with the lower magnification we can just observe the 1 mm line.
Calibration slide seen at lower magnification with Veho microscope. Only the 1 mm line inside a circle is distinguishable.At the higher magnification we can distinguish the 0,01 mm (10 microns) divisions inside the 1 mm line. Not bad for a less than $100 microscope.
Calibration slide seen at higher magnification with Veho microscope. The 0.01 mm (10 microns) divisions are distinguishable.Software. These microscopes come with a bundled software. Though, I prefer a free software, MICAM, download here.It works with any of these USB microscope and let you calibrate your microscope with a calibration slide.
Pigments. I tried Veho VMS hand-held microscope on my collection of gum Arabic painted swatches of historical pigments.
Yellow Pigments swatches observed with a USB microscopeI also have microscope mounted slides of the same pigments, so it is useful to compare how pigments look both painted and dry on a prepared slide of dry pigments and Cargile meltmount.
Pigments microscopy slides prepared with Cargile meltmount.Below are some observations.
Reds
Cadmium red. Synthetic pigments have grains smaller than 1 micron and cannot be detected. Red ochre (gum Arabic swatch). Natural mineral pigments such as red ochre are characterized by grains of different size and colors. Red ochre (mounted slide) is heterogeneous in both size and color of grains. Vermilion (gum Arabic swatch) shows many dispersed black grains. Indeed, vermilion is known for degradation and blackening.Greens
Green earth (gum Arabic swatch) looks heterogeneous both in color and size of the grains. Green earth (mounted slide). It’s characterized by heterogeneous distribution of minerals in size and colors.Greens
A mineral pigment such as malachite (gum Arabic swatch) exhibits a richer texture than industrial pigments such as cobalt green (below). Malachite (mounted slide). Its crystals are well defined and well compares with the image of the malachite on gum Arabic swatch. Industrial pigments such as cobalt green (gum Arabic swatch) are perfectly homogeneous and do not show any texture. Verdigris (gum Arabic swatch) is characterized by well defined crystals. This variety was pretty course.Blues
Azurite (gum Arabic swatch) has defined crystals homogeneous in size and color. Ultramarine natural (gum Arabic swatch) has characteristic white inclusions. Ultramarine natural (mounted slide). It has characteristic white inclusions.Observation on early 1900 paintings.
Hand-held microscope can be used to check the size, color and shape of pigments grains directly on the surface of a painting. Retouches are clearly over original craquelure. Observation on the painting. The blue pigment in the sky is a ground mineral since it exhibits large blue grains. Probably ultramarine as suggested by the infrared false color.This video shows that you can take great video with an hand-held microscope which give a 3D feeling of the surface texture. details on this video are in this blog.
Canvases and textiles
An Hand-held microscope is a perfect tool for thread counting. Once calibrated to shot a 10×10 mm image it allows to characterize the canvas in terms of thread count (in this image 14/12 cm).Inks and pencils.
This image – taken from a written canvas – shows the characteristic flakes of a pencil. Ink writing. Compare this image with the one above to tell the difference between a pen writing with a fluid ink and a pencil.
This is really useful – thanks for posting!
Hi, thanks a lot! I wish i could know about other USB microscope on the market, if anybody has pictures to share. I know DINO USB microscope is 4 times more expensive. I really would like have pictures to compare and see if it’s worth that extra cost.
Thanks for this blog! I’ve used both Dino USB and Veho USB at work and I own a Veho. In my opinion the extra cost for the Dino is not worth. I’ve got satisfactory pictures and videos with VEHO USB and done research and very good visual documentation as well. I’ve chosen Veho mainly because of its compatibility with my Mac Book Pro – though unfortunately, with the latest upgrade of the OS, the “old” software from Veho microscope doesn’t work any more. I’m not sure, but it could be a disadvantage using Veho, because it’s software doesn’t seem to be updated very often.
Hi Elisabetta, thanks for your useful information. I actually was myself curious if Dino was worth its cost and other colleagues were asking me the same thing.
Regarding the software’s issue: if you were using windows I would have suggested you to use freeware MICAM (there is a link on the blog). Unfortunately, I don’t know of any other alternative for Mac. MICAM is a little piece of software, so it will work also on an old pc/laptop that you could dedicate to your USB microscope.
You’re right Antonino. I’ve made the same conclusion: I should have a laptop(with windows) for the use of my USB microscope. I’ve marked the link of the software you recommend in your blog. Thank you for sharing your knowledge!
eheh..knowledge is that think that doesn’t make you more poor when you share it!!!
Indeed!
Hi, great post that really has me seriously thinking about getting a USB microscope for looking at paintings…I was doing a bit of research and came across Firefly microscopes, which offer wireless function – this seems to be a really clever idea and I wonder if you have any experience with them? They are more expensive, like the Dino-lite. It also has a button on the microscope you press to take the picture, perhaps easier to use?
Hi Bettina, I would suggest you to buy the Veho model I showcase in my post or a similar model.
1. I don’t feel wIreless function is that useful, at least for my workflow. The cable has not been a big problem. You need the laptop close to you to see the images and check the focus before you shoot, and furthermore even if some USB microscopes have their own little monitor, it is very little and you are not really sure the pic is actually on focus.
2. All the other USB microscopes have a shooting button on their body.
So, my suggestion is buying one of the cheap models, practise with it and hopefully something better will come on the market later on.
Read the comments, some readers suggested other cheap models.
I did contact Veho company to suggest them to develop a model with functionality useful for art examination but i seems it is a small market for them to think about investing in it. But I’m keeping looking for somebody interested. It would be an instrument also useful in general for forensic science. Ciao!
Thanks for the suggestions, very helpful. I am curious if you’ve ever tried the ViTiny which has a screen like a small digital camera, that seems to give more flexibility of working without a laptop, not sure though if its easy to focus on the small screen. And it is very expensive. I think I will follow your recommendation and try one of the cheap models first.
Keep up the great work with your blog, I regularly read your posts and find them very helpful.
Bettina, thanks for your appreciation of my blog! Yes, just go for a cheap one and as soon as I know of something better, I’ll post about it. Overall, by the comments I got on that post, it seems that the expensive ones don’t give more quality.
In my opinion the Dinolites, thogh good in principle, are not worth the extra price.
I’ve used several Dinolite models costing hundreds of Dollars and found them not much better than the Celestron 44302 , 2MP , which cost me $40.
I also got the same experience from another colleague. Let’s go then for budget USB microscope!
[…] if this autofocus microscope showcase a 5MP camera its magnification is about half that of the Veho VMS 2MP USB microscope. It has only a digital zoom, so you can magnify on its bundled software live view window until […]