Quote: I cannot call it "fundamental" [...]
Not even with that definition

:
Fundamental
* being or involving basic facts or principles
* at a deep and basic level
OK, so at least I can use "crippled" again

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Could we agree that leaving out a feature or a choice is generally not an improvement?
The K-50 features sealings and illuminated focus points, the K-500 not.
Would "crippling" describe this procedure correctly?
Quote: At least you could use your FA Limiteds and the DFA with the aperture ring set to A? Unless you're intentionally fighting the equipment instead of using it.
I mostly do, because Pentax/Ricoh
forces me to do so.
You know why, because the mount is ... [insert proper wording here]

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Quote: None of the uses you describe involves products currently in production.
Ok, first I was accused that problems only arise for lenses older than 30 years. I have then shown that there are issues with much younger lenses and even currently available products. Now, the rules of the game should change again to "products currently in production"? This is unfair

. Furthermore, I must confess that I do not really know, which products are currently in production. Most of them seem to be produced in (small) batches. There are indications that the FA limiteds and even some A lenses have been put together in Japan until quite recently. If you order - say the extension rings - and they are not in the "inventory", they might be "produced" even today - like the FA* 600/4 was available on demand for a long time. Compatibility is not in antagonism with modernization here. I want just more functionality and not less. They shall not move the K-mount backward but forward (which includes better backwards compatibility).