Originally posted by dmfw If someone upgraded to a FF from a smaller sensor, I assume they would need to invest in better (newer) glass. Would they be better off, in the long run, spending the money on Canon/Nikon vs Pentax? I like Pentax, but there are so many pro level Canon/Nikon lens options. A better resale value for Canon/Nikon due to more owners. Also, rental options for Canon/Nikon mounts.
What about Pentax's long term FF commitment. If their first FF camera undersold, would they continue in the FF market?
In
my opinion (and your mileage may definitely vary)...
As to the question about needing better/ newer glass when "upgrading"... disregarding pixel-peeping/ measurebaiting,
it depends. On 1) technique, 2) the sensor, 3) the quality of the glass (new
or old), 4) what you plan on doing with the image, and 5) whether or not the resultant image quality meets your needs.
Just because a lens is "old" doesn't mean it might not be able to perform to the level of quality
you need. Lens "X" may test as much worse than lens "Y" in the labs, or at 100% on a computer screen, but at normal viewing size or print size lens "X" actually performs quite well.
I shoot FF Nikon (D700) and use 30+ year old Ai-S manual focus lenses more frequently than the new AF lenses. The old MF lenses are adequate for my current viewing and printing needs, and are much more enjoyable to use. Do they match the new super lenses with the magic-pixie dust (nano-coatings)? No. But they still produce pleasing and usable images.
More important issue is whether or not your current lens(es) produce the image circle needed to work with a FF sensor.
Would someone be better off going Canon/ Nikon? Right now, they both have had FF cameras for years, have the lenses, have the established customer base. There is a decent sized support community of equipment rental sores, dealers, etc... Not saying Pentax cannot compete, I think they can. But it will be a smaller base, at least starting out.
This is going to be a highly personal decision, based on individual need. Does Pentax produce what you need? Do you need it now? Or can you wait for them to develop and market what you are lacking? Answers to those questions will determine if it might be better to move to Canon/ Nikon, or stay Pentax.
Long-term commitment? I can't speak to the level of commitment Pentax/ Ricoh would have, if FF failed to meet sales expectations.