[Fat Albert]

Should this work, in theory? What does one lose, besides open aperture metering? I think it'd be worth the trade-off to be able to use K and M lenses in AV mode, instead of using the Green button. Has anybody done this?

[Adam]

Yup, it should work if you're fine with doing that to your lenses.

[Fat Albert]

Yup, it should work if you're fine with doing that to your lenses.

The implication is that this is a destructive, irreversible process. Can't one just unscrew the lever?

[Adam]

I'm not sure how complex the mechanism is from lens to lens, but if you have the expertise then you could certainly give it a shot. I don't see how it would be irreversible unless you broke something.

Adam
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[Fat Albert]

I'm just trying to weigh this on a long-term basis. The odds of Pentax de-crippling the K mount in the future aren't very good, in my opinion. The continued presence of the Green Button is a testament to that. I'll never use these lenses on a film body. Truth be told, the K/M lenses stay on the shelf a lot because their use demands a very specific set of circumstances. It'd be nice to liberate them, so to speak.

[lavascript]

Should this work, in theory? What does one lose, besides open aperture metering? I think it'd be worth the trade-off to be able to use K and M lenses in AV mode, instead of using the Green button. Has anybody done this?

I have one M lens and use it in M mode with green button, but I want to make sure I'm understanding the situation, because I don't even know that I am aware of all of the use cases.

With my M50/1.7, if I want to shoot in f/11, I set the camera to M, the lens to 11, look through a bright viewfinder, hit the green button, then the shutter. I cannot use Av mode with this lens, right?

If I were to snip the aperture or get an M42 copy or whatever, then I would set the camera to Av, the lens to 11, look through a dark viewfinder, and hit the shutter.

Pro: I save a button press.
Con: The viewfinder is dark.

Personally, I don't see how hitting a button is that big of a deal, but maybe I'm missing something.

[Fat Albert]

I have one M lens and use it in M mode with green button, but I want to make sure I'm understanding the situation, because I don't even know that I am aware of all of the use cases.

With my M50/1.7, if I want to shoot in f/11, I set the camera to M, the lens to 11, look through a bright viewfinder, hit the green button, then the shutter. I cannot use Av mode with this lens, right?

If I were to snip the aperture or get an M42 copy or whatever, then I would set the camera to Av, the lens to 11, look through a dark viewfinder, and hit the shutter.

Pro: I save a button press.
Con: The viewfinder is dark.

Personally, I don't see how hitting a button is that big of a deal, but maybe I'm missing something.

Correct. Now imagine that your subject is moving from light to dark, etc and you're missing shots either because you forgot to push the green button and your shutter speed is off, or because while you're pushing the button, the moment passes.

[lavascript]

Maybe it's due to the fact that I never really owned a film camera, but if I was having to deal with changing light or subject, I probably wouldn't pick a manual lens. Also, I'm a back-button-AF'er, so I'm used to being required to hit a button before releasing the shutter. I would just hit a different button.

I feel like I'm coming off condescending, and I'm really not intending to.

[Fat Albert]

Maybe it's due to the fact that I never really owned a film camera, but if I was having to deal with changing light or subject, I probably wouldn't pick a manual lens. Also, I'm a back-button-AF'er, so I'm used to being required to hit a button before releasing the shutter. I would just hit a different button.

I feel like I'm coming off condescending, and I'm really not intending to.

Not at all! Different strokes for different folks. I'm also a back button AF user.

The green button is fine for landscapes on a tripod. With more dynamic subjects, it quickly becomes a PITA.

I make it a point to exercise my MF lenses and skills. As folks like Canada Rockies and others say, there was a lot of MF action shooting back in the day. I'd like to refine my abilities a bit

[pathdoc]

This is one of the reasons why I prefer A mount MF lenses and Takumars to K and M mount, but if I stumbled across a good and cheap K or M I wouldn't turn it down for the need to press a button. The button pressing doesn't make much difference for me anyway; most of my MF lenses are not used to take action shots, and if I anticipate that they are, I take an M42 and set to Av mode. There's only one lens I have that really needs the Green Button, and that's sitting on a film body right now.

I would not mutilate a good lens. IMO if you want M42 functionality, get an M42 lens. Especially don't destroy a K or M mount Pentax lens if you're going to mount it on a Pentax camera!

[gofour3]

Yeah please don't mutilate an old K or M series lens, it's hard enough finding a good copy of some as it is.

Why don't you get a #1 K Series manual extension tube instead and mount your K/M lenses on that. The manual tube has no aperture linkage so it will turn the K/M lens into an M42 equivalent without you having to deface the lens.

Of course you will be doing close-up shots, but these are the most fun for manual focusing and you will get lots of practice.

Phil.

[monochrome]

Whether the lever just pops out depends on the lens. Also, some depend on positive spring pressure from the lever to keep the aperture engaged at the right point.

Idiots over in Canon land have been mutilating K mount lenses for years, usually by simply snapping off the lever, in order to get them to work on their 5ds without the mirror getting broken.

i have a K35/2 some Canon phlegmwad pre-converted just to suit your needs. Want it cheap?

[Fat Albert]

I can see that some people are getting the vapors. NOBODY IS MUTILATING ANYTHING. I'm trying to determine if there is a non destructive, REVERSIBLE method of removing the aperture lever.

Find me an M42 Pentax 28/2 & 30/2.8--until that happens, I'm going to explore the option.

NB: NO LEGACY PENTAX GLASS WILL BE HARMED IN THIS PROCEDURE. If it's destructive, I won't do it.

[vonBaloney]

I can see that some people are getting the vapors. NOBODY IS MUTILATING ANYTHING. I'm trying to determine if there is a non destructive, REVERSIBLE method of removing the aperture lever.

Find me an M42 Pentax 28/2 & 30/2.8--until that happens, I'm going to explore the option.

NB: NO LEGACY PENTAX GLASS WILL BE HARMED IN THIS PROCEDURE. If it's destructive, I won't do it.

Depends on the lens, some are easy, some are not. You'll probably have to at least carefully unhook a small spring (and maybe even dissolve a bit of glue keeping it in place). I have taken the lever off only one lens I think, just because I noticed it was easy and I use it often and prefer it that way (the Revuenon/Cosina 55/1.2). I have chopped a couple of cheap lenses too where the aperture was sluggish (and so it didn't work with the lever) and I wasn't able to get the mount off to fix it (or I could, but it couldn't be fixed otherwise).

You can also just not mount them all the way and you'll be able to stop down, but that's a bit fiddly and you risk it falling off if you're not careful...

[Fat Albert]

I've tried the whole deal with not mounting them all the way and it scares the hell out of me.