alanr0

Agreed. The "effective aperture" meaning is generally obvious to the regulars posting and reading this forum.  We are mostly concerned with the optical aspects of how the sensor samples the image, ...

<snip> Not only that, but there is a good chance it won't follow Poisson statistics.  Leakage currents often exhibit substantial 1/f or flicker noise.

An important point which many (including myself) often overlook. The conventional shot noise formula applies when the current is generated via random events at a potential barrier such as a PN ...

Another vote for Spectralon - I used it to support test pieces inside an integrating sphere about 30 years ago, and found it did what was required - though we were not looking for ultra-precise ...

<snip> I think it comes down to a question of degree. I am sure the smaller aperture lens can be somewhat smaller and lighter for the same IQ.  At the crudest level, one could take an f/1.4 design ...

How cheap? How large? How flat? Respected sources for optical kit are Thorlabs and Edmund Optics . You can often buy cheaper elsewhere, but they are a good starting point. Comar in the UK are often ...

<snip> Jack, Agreed - Joofa may have a case that use of lw/ph and lp/ph to describe spatial frequency is undesirable. However, it is clear that Imatest in particular use (0.5 x lw/ph) = lp/ph = cyc ...

Good point, and particularly useful for macro photography, where one is more likely to be thinking in terms of magnification (and worried about DoF). Working F-number is a useful concept here, and ...

Agreed - provided that you measure distance to the entrance pupil.  The angle subtended at the subject by the entrance pupil is what matters. Useful discussion - thanks for posting.

Not so, as it happens.  For macro work, it also makes a difference where the entrance and exit pupils are located with respect to the front and rear principal surfaces. Toothwalker has a derivation ...

Have you tried to contact Horiba? http://www.horiba.com/scientific/products/diffraction-gratings/catalog/flat-field/ Or these guys: https://ssioptics.com/cart/index.php?dispatch=categories.view&cat ...

Are you looking for filters or a complete instrument? For filters, just Google "edge filter". https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=999 http://comarnew.realnet2000.co.uk/filter- ...

For broad band UV/IR operation, won't you need an order sorting filter (higher order blocking filter) to prevent, e.g. 800 nm detector responding to 400 nm light? https://www.newport.com/t/grating- ...

Pentax K-01 had no EVF, but otherwise much of what you are asking for. https://www.dpreview.com/products/pentax/slrs/pentax_k01 It didn't catch on in a big way - was that a problem with the concept ...

That changes the drag and drop behaviour. Not a problem if you use it from the command line. For my Pentax, the tags are -PentaxModelID and -ShutterCount. These are in the proprietary MakerNotes ...

No problems here with exiftool 10.49 under Windows 7. What is your operating system? Are you able to read the documentation when you double-click on the executable? Is the executable still called ...

That's exactly what a telephoto lens is. A lens with a physical length shorter than the focal length. Otherwise, strictly speaking, it is just a long focal length lens. https://en.wikipedia.org/wik ...

Thanks for chipping in Jack - a useful reset of the discussion. As far as I can tell, this Wikipedia page explains the most important focal lengths pretty well. Strictly speaking, the object and ...

Agreed, and not what I was implying. FFL and BFL are different for a plano-convex or other asymmetric singlet.  Effective focal length is the same when measured to respective principal planes in ...

Not as far as I can tell with respect to FFL (see below). <> Judging by the ray diagrams AiryDiscus linked , Code V actually reports FFL as distance from focus to vertex of first glass surface, and ...