how to do cutting edges ?

Lothar-Gutjahr · Post by **Lothar-Gutjahr** » Tue Jun 04, 2013 3:19 pm

Hi,

i would like to ask, if someone did microfotos of edges from cutting devices. I find it one of the most difficult matter. Today i used the B + L 50 U.L.W.D. with B + L 10 x ocular projection. Ilumination two ledlights and diffusor.
The object was a new rasor blade of a oneway rasor.

The foto was stacked with Zerene in Dmap mode using 28 Fotos 1 µm apart. The object was allmoust paralell in plane not to need much fotos. After sharping a little it undervent a short visit in the new Clarity from DxO labs
I realy would like to know if one could do this much better ?

Thank you

Lothar

ChrisR · Post by **ChrisR** » Tue Jun 04, 2013 3:37 pm

I'm not sure what I'm seeing..

There's a band of grinding lines, coloured by what looks like speckles. (More diffusion might change the appearance of that?)

Then above, after the dark part (different angle?) there's a pale band lighter than the background, with a "tooth" projecting into it. Is that the polished edge?

I've noticed a couple of different constructions ( therefore alloys, I assume) of disposable razor blades.
Sometimes there's a hard strip spot-welded to a stronger L shape, for rigidity.
Sometimes there's evidence of high-frequency induction hardening, right at the edge of a blade.
I believe they're sometimes heat treated on the edge by laser.

They're sharper and thinner than scalpels. With care they can be used to cut finer things!

Lothar-Gutjahr · Post by **Lothar-Gutjahr** » Tue Jun 04, 2013 11:17 pm

Hi Chris,

thanks for looking ! This 500 x fold enlarged foto on a redish background shows a stripe of halo from stacking. What you call the dark part ( diferent angle) is the polished edge an everything on top of it is background including the pale band.

I´ll give it another try with more diffusion and also try Pmax mode while stacking.

have a nice day

Lothar

rjlittlefield · Post by **rjlittlefield** » Tue Jun 04, 2013 11:29 pm

DMap should be the best method for stacking this sort of subject, because it has simple geometry with no overlaps and no sudden changes in depth.

The halo we see here will not be produced by DMap when it is used as intended. I suggest reviewing How To Use DMap to learn about using the slider to make background "go black in preview". For this sort of subject you will need a slider setting around Percentile 50.

--Rik

Lothar-Gutjahr · Post by **Lothar-Gutjahr** » Wed Jun 05, 2013 2:12 am

Hi Rik,

thank your for your comment. The existence of that halo is amplified by my contrast enhancement methods. But i will try to play a little on that slider setting. Used was 55 %
Here for further discussion the metall edge with green background

Lothar-Gutjahr · Post by **Lothar-Gutjahr** » Wed Jun 05, 2013 3:49 am

Hi Rik,

the problem is solved thinking about the halo. This time i used Clarity only without clahe. The clahe enhancement digs out unvisible rests of halos and amplifies them.

This is 51 % im Dmap and Clarity in macro mode and a little bit unsharp mask before.

Greenfields · Post by **Greenfields** » Tue Jun 11, 2013 10:50 am

I understand that the magnification is 500x on the sensor.

Would you say what sized sensor your used and whether you have shown the entire image or a crop, please ?

Lothar-Gutjahr · Post by **Lothar-Gutjahr** » Tue Jun 11, 2013 11:52 am

Hi,

i used the B + L 50 U.L.W.D. with B + L 10 x ocular projection which calculates to 500 x fold. The camera was Canon 1000 D and full view, no crop. The CMOS sensor has a size from 22,2 x 14,8 mm and i dont know if that is same as a the so called APS-C-Sensor?

Using my "UFOMI" with M 42 bellow i have no chance to compare to a ocular view. My viewing is a 32" flat screen in lifeview mode.

I hope this helps you. Thanks for stopping by.

Lothar