Thread: Compound magnification

I spent a night a week for about 8 weeks when i worked for a major multi just learning a tiny bit about lenses. Focal length is the key and inter lens spacing is the answer, but, even with those things right, there may only be a little sweet spot in the middle of the lens at that magnification. A lot of things happen as light is diffracted and diffused through glass and different colors behave differently in a given lens.
~Richard

Originally Posted by Geezer

Whatever you use, It is the angle at which the light consistently strikes the bevel and edge which is most valuable. an angle somewhat 45º to the length of the blade and a bit higher will tell you a lot. A dark background helps for lighted loupe work and a neutral or black background may help to assure the bevel is to the edge fully along the length of the edge.
A bright light source across a room and looking from the spine side of the horizontal blade as it is rotated slightly around its long axis to see bevel reflections along an edge will tell a lot when you get to know what you are looking at.
~Richard

Got it thanks Richard

Originally Posted by Geezer

I spent a night a week for about 8 weeks when i worked for a major multi just learning a tiny bit about lenses. Focal length is the key and inter lens spacing is the answer, but, even with those things right, there may only be a little sweet spot in the middle of the lens at that magnification. A lot of things happen as light is diffracted and diffused through glass and different colors behave differently in a given lens.
~Richard

So true.

You really see it more with telescopes than microscopes. The eyepiece objective can come in all types of configurations Symmetrical, Plossl, Erfle, Orthoscopic, Konig, Nagler,Huygen, Ramsden and achromatic and non achromatic to name a few-har har.

Each configuration has different qualities depending on if you are using low or high power and want good eye relief and color correction and wide angle or not.

There's nothing like looking into a 2mm eyepiece which is smaller than the pupil of your eye.

Thanks everyone for your suggestions and knowledge base. I'm waiting for my set of loupes to come in. The set contains 2-10x, 1-20x, an 1-30x so that if anything and I am not going to be able to work I'll at least have more than I need. They should be in by Thursday so it will be interesting to see what happens and maybe to come up with a way to stabilize the loupes at their relative focal lengths to get the most out of this experiment without a lot of overhead.

Originally Posted by rlmnshvstr8

Thanks everyone for your suggestions and knowledge base. I'm waiting for my set of loupes to come in. The set contains 2-10x, 1-20x, an 1-30x so that if anything and I am not going to be able to work I'll at least have more than I need. They should be in by Thursday so it will be interesting to see what happens and maybe to come up with a way to stabilize the loupes at their relative focal lengths to get the most out of this experiment without a lot of overhead.

What you will be looking for is anything but a clean line of bevel from the spine side of it to the very cutting edge. Use reflection to see if there is any secondary bevel near the edge. That is all. Just a matter of training yourself to watch for deviation of colors / brightness across any particular length of the bevel.
Now...To save many hours!!!
One other thing, before you even start to hone...Find a really flat item larger than your razor. Pick up it and your razor with the light coming toward you from some bright source. Check that the edge is perfectly straight or slightly smiling and another check to see it the spine is straight by laying the edge each side flat onto a perfectly flat plate, or sheet of glass or a previously lapped hone. Any light from behind means you will know where to start your work.
Above all, have fun and quit when you start to get frustrated. It does come relatively easy after some seemingly eternal time period.
~Richard

I received my loupes in the mail. And after a day of playing around and doing a little bit more research on focal length, I can say it works. Adding two jeweler's loupes in series once placed in correct distances will produce a decent magnified image that is more than either loupe by itself. Issues that I noticed is getting the lighting at the right angle to the blade to see the scratch pattern clearly, ambient light can make the image brighter and harder to see and some light distortion as the reflected light from the blade goes through the lenses. The hardest thing was getting the lenses at the correct distances. If those are overcome this can work.

Note: it is obviously better to have a loupe or microscope with better mag if they are on hand for better optics and control. This was only for me to see if I was just wanting a little closer look and I only had two loupes to use can it be done not must it be done. And as a final note because of quality and that this is not an actual microscope you will not get to the exact multiplied value of the two loupes but at least when done right at leat 50+%

Oh I forgot to mention because of some of the reflected light distortion the magnified image puts me in remembrance more of a phase contrast microscope rather than a compound light but the image can be clear enough to see if the bevel is set.

They sell them like that. I have a Zeiss which has two lens ganged together so you can use either of the two apart or swing them together and use both.

Could you send a link. I would love to look at it.

~Richard