The Pentax 1.4x DA AF converter yields excellent results on my K3 with the DFA 150 -450 or on the K-1 cropped. On the K3 I get the reach of a 960mm lens, razor sharp. Paul
> On Jul 28, 2025, at 3:20 PM, Larry Colen <[email protected]> wrote: > > > >> On 2025-07-28 09:51, John Francis wrote: >>> On Sun, Jul 27, 2025 at 06:25:56PM -0400, Sandy Harris wrote: >>> Is the text on teleconverters here reasonable? Or, for that matter, >>> the rest of the article? >>> https://en.wikivoyage.org/wiki/Travel_photography/Full_systems#Telephoto_lenses >> Most of the article is reasonable (although there's nothing really >> said there that any experienced photographer wouldn't already know). > > It pretty much matches my experience. > >> But there is one 'suggestion' there that I find totally ridiculous; that >> one way to get a narrower field of view is to purchase a small-sensor >> body (with the same lens mount) to use alongside your full-frame body. >> Almost all the small-sensor bodies I know have no more pixels in total >> than the same area of the larger sensors in the full-frame body, so all >> you get by adding a different body is more weight to carry around; >> simply cropping the full-frame image to the area of interest will yield >> an image at least as good as the one you would get from a smaller sensor. > > The per pixel resolution of the K-3 is a little higher than the K-1, but not > dramatically so. I.e. the K-3 III will have more pixels than the K-1 in crop > mode. > > Here are my thoughts: > > Note what the diffraction limit is on different sensors. TL;DR for the > most part it seems that most modern sensors are pretty close to out-resolving > most lenses. This is the reason that anti-aliasing filters are going away. > > At one end of the spectrum, you have people doing things like > astrophotography, > where the absolute resolution of the final image is critical. If they are > already > using a high resolution sensor (as opposed to Tri-X film), and processing the > raw files using a teleconverter doesn't seem to improve final image quality, > and could degrade it. > > On the other hand, if someone is just taking the jpegs out of their camera, > and not doing any post processing, or they are using film, or a low resolution > sensor, then a teleconverter could help. > > A lot of image quality does come down to how many photons hit the image area > of the sensor, or the pixel. Adding a TC can't put any photons there that > weren't > there with the base lens. > > -- > Larry Colen [email protected] http://red4est.com/lrc > -- > %(real_name)s Pentax-Discuss Mail List > To unsubscribe send an email to [email protected] > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- %(real_name)s Pentax-Discuss Mail List To unsubscribe send an email to [email protected] to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
