| Author | Message | ||
     james randolph hillard Silver Pheasant Username: hillarjr Post Number: 177 Registered: 12-2005 Posted From: 152.sub-75-198-120.myvzw.com |
There are now relatively inexpensive digital microscopes that connect to the computer and take pictures at anywhere from 10 to 100X magnification. Has anyone used one of these? If so, is there a model and brand that is recommendable? Thanks! | ||
| Giovanni Repetti White Crane Username: grepetti Post Number: 3899 Registered: 12-2003 Posted From: host254-39-dynamic.6-87-r.retail.telecomitalia.it |
Dear James, I do not suggest you to buy such devices, at least this is my opinion based on the few ones that I have seen on the net. Reasons: low resolution and, more important, poor lens design. The best solution is a regular microscope with the proper camera attachment. As a second solution, just place the camera lens against the microscope ocular. A sort of compromise but the results are much better than the USB microscopes. Anyway, I don't suggest you large magnification rates. For our use, low rate are better, 4X to 10X enlargement are enough. Giovanni | ||
| Arno Jacobs White Crane Username: jcbs Post Number: 3439 Registered: 07-2004 Posted From: ip4da26c4f.direct-adsl.nl |
Hi James, There are some threads where some members do have showd the working with such camera's, and I think that the pictures are very good. I hope to hear from those members what they use. I am looking for such camera too, but it has to be good and cheap otherwise I use the camera and zoom in. Kind regards, Arno | ||
| Garrett McCormack Silver Pheasant Username: g_mccormack Post Number: 86 Registered: 11-2009 Posted From: fl-67-237-127-186.dhcp.embarqhsd.net |
James, I have purchased two USB microscopes. One was $30 bucks and one was about $60 I think. The cheaper one was pretty much useless. The other I have spent a few hours fooling with, but not much more time. I'd love to stumble onto a deal on a nice used reflected light microscope with camera hookup, for use in analyzing metallurgical and porcelain specimens, but until I find that deal I'll have to use this and the macro lense on my camera. If you want to have fun, maybe learn something, and satisfy your curiosity, I'd say read some reviews and try one out. Giovanni is completely correct about the drawbacks of these things- poor lighting, image shake, focus challenges- but you can still have fun. Here are some shots I got. I only labeled the scale on a few pics because I had just figured out how to do it.      | ||
| Michael Anders Lesser Egret Username: miken Post Number: 9 Registered: 12-2010 Posted From: 2109ds3-vby.0.fullrate.dk |
Hi James, Buy one! It is not expensive and you'll have some good experience using it, and definitely it will come to some good use. As they say if you wait for the latest model of a laundry machine you still wash by hand! I have one of the units you mention, bought it out of Hong Kong on a major auction site for thirty something USD incl shipping. There are drawbacks as described. If you go for it: take one with buttons for both focusing and magnification. The one I got had only adjustment for focusing and the distance I hold it from the object determines the magnification. This means that if I use the clip that it came with the magnification is perhaps 100 to 200 times which is often much more than you actually need and if I need less I have to raise the microscope up by hand or using books to put it on. Needless to say this is pretty worthless. But for removing splinters or examining items with huge magnification it is pretty good. Best regards Michael | ||
| Walter Susor White Crane Username: wsus Post Number: 1930 Registered: 08-2003 Posted From: adsl-75-7-3-34.dsl.pltn13.sbcglobal.net |
Hello, I have been using a surplus laboratory model stereo dissecting microscope that is designed for biologists. It has a long focusing distance that is ideal for inspecting ceramics. The stereo viewing allows me to actually see in three dimension through the depth of the glaze. The only drawback is that stereo photos are not practical. I did try a microscope adapter for my camera but it did not work as well as the macro function of the camera alone. I have higher power oculars for the microscope but do not use them. I find that 8-15x is ideal. Greater magnification does not give useful information. The fiber optic light source is a surplused one bid ebay purchase that has proven well worthwhile. The bowl is in perfect focus at this distance.  Regards, Walter | ||
| Garrett McCormack Silver Pheasant Username: g_mccormack Post Number: 87 Registered: 11-2009 Posted From: fl-67-237-127-186.dhcp.embarqhsd.net |
Walter- very cool setup! I'll be looking into replicating it for myself. Cheers | ||
| Giovanni Repetti White Crane Username: grepetti Post Number: 3943 Registered: 12-2003 Posted From: host158-39-dynamic.6-87-r.retail.telecomitalia.it |
Dear Walter I totally agree with you, I was going to post each one of the points you have mentioned. Big enlargements are not useful. The stereo microscope has great advantages. The great distance of focus, beside allowing a big free space between the microscope and the object, will allow to look at the bottom of bowls which in many cases is not possible through monocular microscopes due to the limited space. And the stereo vision is really spectacular. It seems to see the bubbles coming up during firing. Really a pity that a single picture can’t catch that. And I too suggest fiber optic illumination which is important to avoid localized heating of the piece. Second hand stereo microscopes can be found at reasonably price on ebay and it really worth the investment. Kind regards Giovanni | ||
| Walter Susor White Crane Username: wsus Post Number: 1931 Registered: 08-2003 Posted From: adsl-75-7-3-34.dsl.pltn13.sbcglobal.net |
Hi Giovanni, Here is a challenge: In earlier posts, Nick Hopton was able to record and play back the sound of porcelains being pinged. No one has followed up on his methods, but the potential usefulness is evident. Unfortunately, Nick's sound files are no longer available. http://www.gotheborg.com/discus/read.php?file=/207/78796.html&lm=1110214841 http://www.gotheborg.com/discus/read.php?file=/11760/79222.html Within the state of existing technology it should be possible to produce and view stereo images on-line. I have seen stereo images printed in journals that can be viewed (with some difficultly) without special equipment. It would be exciting if we could view stereo images of objects in our collections. I have been thinking of buying an old stereo camera and modifying it for macrophotography and printing the images for viewing with an antique stereo viewer but viewing would be tedious and difficult to share on-line. The challenge is to devise a way to share stereo images on-line. Or has someone already done this. Viewer for stereo cards  This scene can be viewed in 3D by holding a card in line with your nose so that the right eye sees the right image and the left eye sees the left image and squinting until the two images merge. It is a lot easier if you use a stereo viewer like the one shown above.  Walter | ||
| Giovanni Repetti White Crane Username: grepetti Post Number: 3945 Registered: 12-2003 Posted From: host158-39-dynamic.6-87-r.retail.telecomitalia.it |
Dear Walter, my brother has, hided somewhere in the big mess of his house (surpassed only by my own house), an old stereo vision device like the one you posted, most important together with a series of stereo pictures took in China during the boxer rebellion. I have been crazy in trying to find them a couple of times, aiming to post the pictures here on Gotheborg but with no success. I hope to find them in the future. Years ago I made several stereo slides with a standard camera. The trick is as follow: you take one picture and you pay attention to one reference point, as for example the exact point of the image that is coincident with the focussing circle at the center of the viewfinder. Then you move your body to the right about 4-5 inches, and take a second picture trying to center again the reference point in the same position. Place the two slides in two slide projector and superpose exactly the two project images on the screen. Place a polarized filter in front of each projector lens, being one filter rotated 90 degrees respect to the other one (circular polarized filters are not suitable). Then you must wear a kind of glasses which in turn are made by two polarized filters rotated as the ones in front of the projector's lenses. In this way one eye is seeing one picture only and the other eye is seeing the other image. It gives a great tridimensional effect, you see landscapes through the screen. I suppose that the same way is not working on digital images because the light is originated by the screen and not sent to him by the projectors. I don't use photoshop either so I really don't know. Best regards Giovanni | ||
| Walter Susor White Crane Username: wsus Post Number: 1932 Registered: 08-2003 Posted From: adsl-75-7-3-34.dsl.pltn13.sbcglobal.net |
Hi Giovanni, I would love to see your china cards when you are able to locate them. I have a set of 15-20 from the Philippines depicting early 20th century scenes. The card shown above is one of them. The perception of depth is remarkable when viewed through the prismatic lenses. When I was younger, I could see the 3D effect without the lenses but my eye muscles are too weak now. As an aside-The technicians who produced topographic maps from aerial photographs were able to hold the two negatives side-by-side and see the landscape in 3D without the use of their specialized viewers but it was a learned skill now probably lost forever. Fujifilm makes a 3D digital camera that is somewhat expensive and the images must be viewed on a special 3D monitor or TV so a set-up would be costly and maybe not suitable. I found sample photos on the internet taken by 3D enthusiasts using two camera rigs but their results do not compare favorably with those of the late 19th century stereo card. I am thing that maybe by using a fixed camera and slightly rotating the object on a platform for the second photo, a pair of photos should be obtainable that would give a good three dimensional image. The use of polarizing filters or alternating right-left shuttered images used for movies work well enough but are cumbersome and require the specialized equipment. Thinking out loud. Walter | ||
| Hans Slager Dragon (Board Moderator) Username: hansenclair Post Number: 4432 Registered: 04-2003 Posted From: ipd50a7fc3.speed.planet.nl |
Walter, like you I used to look at stereo pictures in my lab days without needing those lenses. It took me a few minutes but I still can do it ! Fun thing. I needed to zoom out the screen one step (ctrl and '-' in Firefox) so they were about 8cm high on screen. If bigger I couldn't do it. You don't actually need your eye muscles; you need the opposite, relaxed eyes. The trick is to put your face 10-15cm before the screen and don't focus (just stare 'through the screen' into the far distance). Then wait until your brain creates a central image (can take seconds or a few minutes) and keep ignoring what you see left and right). Once you see the 3D image then you can slowly move your head backwards if you like; the brain will retain the image. But keep staring into the distance, your eyes remain fully relaxed then. | ||
| Walter Susor White Crane Username: wsus Post Number: 1934 Registered: 08-2003 Posted From: adsl-75-7-3-34.dsl.pltn13.sbcglobal.net |
Hans, Thanks for providing the correct method for viewing. It has been a long time since I have done this. I'll try again without the lens. Walter It works!!! | ||
| Giovanni Repetti White Crane Username: grepetti Post Number: 3948 Registered: 12-2003 Posted From: host158-39-dynamic.6-87-r.retail.telecomitalia.it |
Dear Hans, thank you, I didn't know that. It works, I can see a central stereo image plus other two images on the right and left side. If I put a piece of paper between the line dividing the two images and my nose, so that each eye is seeing only one of the images, then I only see the stereo image without the two ones on the sides. Giovanni | ||
| Hans Slager Dragon (Board Moderator) Username: hansenclair Post Number: 4433 Registered: 04-2003 Posted From: ipd50a7fc3.speed.planet.nl |
Even better Giovanni ! Walter, Giovanni, I wonder what your families were thinking when they saw you with your head stuck to the screen like that..... "he really needs new glasses"..... hahaha | ||
| Timothy Roberts White Crane Username: porcelain202 Post Number: 2742 Registered: 04-2003 Posted From: c-69-244-61-62.hsd1.az.comcast.net |
Merry Christmas to you Gotheborg addicts. I have finished baking my pumpkin pie, so just waiting while my wife does the remainder of the cooking. You can now buy a full stereo set-up for relatively cheap. The Samsung 2233RZ monitor is about $350, and the nVidia LCD shutter glasses are about $175. A good stereo graphics card with nVidia chip is about $100-$200. Just make sure it has output connectors to support both the glasses and the stereo monitor that you plan to use. Also, Fujifilm has a 3D Video and still camera for $500. http://www.nvidia.com/object/3d-vision-diy.html Tim R. |
