Ion pairs are called excitons and are indeed still currently investigated; Cal Tech recently reported evidence of Hubbard Excitons, with magnetic instead of electrostatic binding. Another consideration: ions are randomly generated in air e.g. by photon collisions. Most of those probably stay paired ...

That's a finite one. In its 100% photo position, does the head impose optics between objectives and photo port? The optiphot 100 equivalent is a little chunkier and all the infinity ones only have two positions (100/0 and 20/80). I saw this Optiphot 100 with 3 position slider: https://i.ebayimg.com...

Optiphot-2_trinoc.jpg Another trinocular head that I have seen only online attached to Optiphot-2; set screws in photo tube suggest a 38mm port adaptable to mirrorless camera bodies. That may be an Optiphot-100 head used without the vertical illuminator, which would then presumably require infinity...

trinocular heads which work with the Optiphot Common trinocular heads for Optiphot/Labophot are F, T and UW. Only F enables direct projection, but switches 100% of beam. T and UW heads designs are similar, with a lens at their entry port converting finite objective rays to infinity for prisms. Both...

on https://www.ebay.com/itm/274696367794 there are two options; 38mm, if your trinocular F has this style photo port: trinocF.jpg Otherwise, for trinocular F with one-piece chimney for photo relay lens, it can be unscrewed, exposing a 42mm thread recessed into the head for this adaptation: https://...

Bruce wrote: ↑

Mon Sep 04, 2023 3:33 am

visualising the way sharpness is compared,

A sharpening filter amplifies single pixel differences:
https://en.wikipedia.org/wiki/Unsharp_m ... ementation
.. then apply thresholding to taste.

what i need to do next need? Only a guess : That macro tube with pentax k.bajonet probably has M42 or T2 threads. here is one kind of 42mm adapter for RMS objectives: https://i.ebayimg.com/images/g/WsAAAOSwygJXhEuc/s-l500.jpg https://www.ebay.com/itm/165634678455 another adapter style: https://i.eb...

I'm surprised that the grooves, in cross section, appear to have structure that appears stratified. Are LP blanks built up in layers? According to "Handbook for Sound Engineers", LP vinyl grooves literally melt while styli are dragged thru them; striations may be from debris that was dragged along ...

Lou Jost wrote: ↑

Sun May 07, 2023 7:11 am

the light source has to be as nearly monochromatic as possible. The easiest way to do this is with a laser.

An expedient is separately processing red, green and blue color channels.
E.g., in IrfanView:
Image->Show Channel
.. then File -> Save as

And yet the camera itself interprets this particular situation correctly -- the JPEG created in camera does not contain the dark band. Camera's JPEG Yuv implementation could be tuned for its hardware artifacts. Note that reviewers are often constrained to JPEG for preproduction cameras. Perhaps thi...

I'm quite sure that by calibrating at enough points on the spectrum, you could create a custom profile that would do a great job of handling spectral colors on a black background. That's just a lookup table driven by the R:G:B ratios in the input. It would be no great trick to turn that D800E's raw...

Beatsy wrote: ↑

Sun Apr 09, 2023 3:02 am

I wonder if generating custom profiles for each of the cameras would smooth out the differences in this case.

A surprising amount of that lack of smoothing arises from algorithms used for creating and applying those profiles.

I have not worked in the field for over a decade, when so-called color science was quite competitive. Considered in that light (pun intended), why would one expect competitors to have identical solutions? To start, there are some practical considerations. traditionally, CMOS image sensors were based...

So it could even be the case that the ocular is responsible for CA correction with these objectives. Yes, and Reichert expertise is available at microbehunter.com, e.g.: When the merger between Wild-Leitz and Cambridge Instruments took place, there were at least 4 infinity corrected optical systems...

assumption is that this and similar programs are looking for an edge and then count the pixels which form that edge and their color/contrast values. With long enough edge it can be sampled many times and then calculate the MTF for this part of the picture based on the pixel pitch. The slanted edge ...