tag:blogger.com,1999:blog-6555460465813582847.post1409841096918178648..comments2023-02-07T10:24:13.796+02:00Comments on MTF Mapper: Nikon D40 and D7000 AA filter MTF revisitedfvdberghhttp://www.blogger.com/profile/06566624298120266140noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-6555460465813582847.post-60895743648316187512021-08-09T01:58:34.039+02:002021-08-09T01:58:34.039+02:00Optical Coating filters<a href="https://www.nano-optic.com/blog/how-optical-filter-work/" rel="nofollow">Optical Coating filters</a><br />amanda josephhttps://www.blogger.com/profile/07513850076484832480noreply@blogger.comtag:blogger.com,1999:blog-6555460465813582847.post-4047270687897910102017-11-30T23:27:24.600+02:002017-11-30T23:27:24.600+02:00That will not be a 'circular polarizer' be...That will not be a 'circular polarizer' between the niobate crystals, but a quarter wave plate. A 'circular polarizer' actually is a normal polarizer with a quarter wave plate on the camera side, so circularly polarized light hits the camera.<br />This also means one could influence the AA filter by using a polarizer.Oh wat mooihttps://www.blogger.com/profile/03727570712905579862noreply@blogger.comtag:blogger.com,1999:blog-6555460465813582847.post-26958223617722977872017-02-23T03:09:24.091+02:002017-02-23T03:09:24.091+02:00In microscopy, the numerical aperture of the conde...In microscopy, the numerical aperture of the condenser has an effect on resolution (https://en.wikipedia.org/wiki/Angular_resolution).<br /><br />Here you were going for even illumination, but I wonder if illuminating the edge with light from the integrating sphere (‘death star’) might improve the observed MTF due to a wide range of light angles, as provided by a microscope condenser?<br /><br />If so, I wonder if illumination factors (eg., angle) would also affect results obtained using conventional paper-based MTF targets. (Though paper probably acts more like a diffuser than a mirror.)<br /><br />ps. thanks for all your postingsCWU 452 397 855https://www.blogger.com/profile/02243951245587840329noreply@blogger.comtag:blogger.com,1999:blog-6555460465813582847.post-70020616266939786452012-12-28T18:13:52.240+02:002012-12-28T18:13:52.240+02:00Very interesting. Is it possible to identify the c...Very interesting. Is it possible to identify the contribution of the OLPF to the MTF50? I.e., how much does the OLPF reduce ( in %) the sensor resolution (assuming a perfect lens and no post-processing/sharpening)?kilianhttps://www.blogger.com/profile/00420391024798365089noreply@blogger.comtag:blogger.com,1999:blog-6555460465813582847.post-26074706536410225042012-11-01T09:38:00.006+02:002012-11-01T09:38:00.006+02:00Thanks you for the valuable input! I have very lit...Thanks you for the valuable input! I have very little information on actual microlens designs (perhaps I have not looked hard enough?), so your comment on the near-circular shape is news to me.<br /><br />I have another blog post in the wings on a new rendering algorithm for simulating combined diffraction and pixel aperture effects. That algorithm allows me to specify the pixel aperture as an arbitrary polygon, so I hope to post some more results soon, taking into account both smaller pixel apertures and non-square shapes.<br />fvdberghhttps://www.blogger.com/profile/06566624298120266140noreply@blogger.comtag:blogger.com,1999:blog-6555460465813582847.post-45920863458697410002012-11-01T09:12:29.211+02:002012-11-01T09:12:29.211+02:00Thanks Jack!
I'll put a up a short post on tho...Thanks Jack!<br />I'll put a up a short post on those deconvolution kernels (hopefully soon :)fvdberghhttps://www.blogger.com/profile/06566624298120266140noreply@blogger.comtag:blogger.com,1999:blog-6555460465813582847.post-38213921893696850362012-10-29T18:36:10.018+02:002012-10-29T18:36:10.018+02:00Nice demonstration !!.
One question, as i underst...Nice demonstration !!.<br /><br />One question, as i understand it you use as aperture the full pixel dimensions while in practice it should be a bit smaller, there is always dead area at the periphery. <br />The percentage of this dead area depends on the pixels structure and the microlences's efficiency (so for the old D40 with not gappless microlences and not optimized structure the apperture can be much smaller). But even with today's "gappless" microlences there are dead areas at the corners making the apperture almost circular.<br /><br /> IliasGhttps://www.blogger.com/profile/16634176593485972197noreply@blogger.comtag:blogger.com,1999:blog-6555460465813582847.post-23569008748209523622012-10-14T16:58:08.984+02:002012-10-14T16:58:08.984+02:00This is just brilliant. One should create a decon...This is just brilliant. One should create a deconvolved image with your PSF and choose when/how much to overwrite the original raw based on noise. Can you suggest PSF kernels for deconvolution for a few of the more common apertures (i.e. 4, 5.6, 8)?Anonymoushttps://www.blogger.com/profile/06552465819763513232noreply@blogger.com