I'll let everyone know how it all looks when it comes in - I bought 2 lens sets in wooden boxes, 4 lense holders, and a diffraction grating ![/quote]
Hi Senkat,
Thanks for listing this site, I've bookmarked it and will visit it again when I get my son an electronics kit.
I checked out thier lenses and prisms and do have a few comments in general.
The prices on the educational sets of lenses are really good. The quality is not too bad, but...there's always a big butt...right?
They are good for primary and secondary school experiments in light. They are not well suited for laser work though. I found this out by getting a large variety of lenses to test. Yes, some where these same ones. It's not the quality thats the main problem, it's the lens diameter. With laser work the lens diameter needs to be smaller than 38mm, the smaller the better. This is becasue to use the lens to magnify, the beam diameter needs to be near the same size as the lens. By near I mean the beam diameter should be no less than ~1/3 the diameter of the lens. There's no fixed rule for this, just my experience. The closer they are matched, the better. Of course if you put the lens far enough in front of the laser so that the beam fills the 38 or 50mm, then all is well; but that can take lots of room. I think for the price they are a pretty good deal though.
The prisms are another matter. The $5.00 equilateral prims are made with plain glass as they are not listed as BK7 or other high refractive index material, they are probably not very flat either. It's the high refractive index that seperates the color of light well, the higher the better. Same goes for the right angle prisms, just plain glass with no mention of the quality. With these you really get what you paid for and for $5.00 for something of that size, your not getting much.
The larger equilateral prism marked as crown material is the exception. The ~30-35 cost is pretty much in line and the material is good. It does not mention the flatness or scratch/dig quality, so there are still some risks.
The lens holders, I haven't researched these, but hey they just hold the lens, so it'll perform it's function. The diffraction gratings looked pretty good...or at least there prices where in line with quality ones.
Give them a review when they arrive and post it here.
I know my kits have some of the larger lenses, but I think I'll be fading them out unless there is a requst for them...at least for laser customers.
If you get a chance, check out my optics kit page, I've just added lots of cool stuff and have many dozens of more lenses and prisms I haven't had time to add, but will try and add 2-3 each day or so until they're all online.
btw, thanks for the comments about the laser discussion eariler today, I felt the same way...great exchange of information...
Jack
