DrewE

The "green button" is a button on the Pentax DSLRs that's used for various things in different exposure modes.  In manual exposure mode, which is all that the DSLRs support for the older pre-'A'...

Yes, it's possible to use the old lenses with new DSLRs (and get good results, depending on the lenses).  The 50mm lens is capable of producing excellent results, assuming it's in good working...

I think it largely boils down to "people use what they're most comfortable and familiar with."  Center-weighted average metering has been around for eons, so lots of people are familiar with it and...

...snip snip... I believe this can be adjusted by shimming the focus screen.  Pentax service should be able to do that.  (Also note that some lenses have some focus shift when stopping down; what...

A few of thoughts and questions... 1.  You are aware, I presume, that the AF sensors are considerably larger than the little squares in the viewfinder, and will sometimes lock onto a bit that's...

That wouldn't work for a normal PK lens as the lens is always wide open when composing (and metering and focusing) the shot, due to the camera holding the stop-down lever in the open position. ...

Personally, I'd go for the newer one because it supports automatic exposure, which IMHO makes it a lot more versatile on the DSLR.  Autofocus is nice, but the full range of exposure modes is nearly...

Flash tubes have a long life--anywhere from 10s of thousands of flashes up to 10s of millions of flashes, depending on the design and usage.  Other components in the flash are at least as likely to...

Registration distance; an adapter needs to take up some nonzero space in front of the bayonet mount's plane.  Nikon lenses have the mounting plane at essentially the same distance from the sensor...

For macro work (well, actually for all photography, but it mainly comes up in macro photography), the depth of field is only dependent on the magnification ratio and the relative aperture.  A 1:1...

That was my thought, too; in the case of unit focusing lenses (quite a few primes), this is essentially asking for a longer focusing helical.  I don't know why that's not so common; perhaps because...

If it is a stuck pixel, it should appear in the same spot in every photograph. To me, this looks quite like lens flare, possibly from a filter (if you're using one).  There appears to be quite a...

Cars do not get anywhere near hot enough to melt solder joints from sitting in the sun; if they did, you would get very bad burns when buckling the seat belt, and car radios and similar electronics...

Many, many things cannot be set in green mode.  Autofocus point selection is one of these things, I believe. Probably what you actually want to be shooting in is P mode; this sets the exposure...

This is true; .AVI (and .mov, for that matter) are container formats, and can hold video and audio encoded using a variety of codecs.  You need to find out more specifically what formats Registax...

KEH is offering them (in their EX condition) for about $200, and buying for about $100.  Based on that, I might aim for $150 as a fair price for a private sale, assuming it's in good condition (as...

Depending upon the software you're using, you could very well be looking at the embedded JPEG in the RAW file rather than a processing of the RAW data itself.  I'm pretty sure that's what is going...

Put it in green mode and loan it to a kid, preferably the youngest one you can find who is sufficiently trustworthy and careful.  You'll get pictures of things and angles you would never have...

Sigma has put a price of $200 for putting a PK mount on a lens once the necessary design and engineering work has been done.  It's obvious to me why they won't retrofit lenses with mounts they...

No, they quite specifically exclude combinations they do not offer new.  That only makes sense—there's more to the conversion than just screwing a new mounting ring onto the lens for modern lenses...