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02-13-2015, 10:36 AM   #16
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They said it's important but difficult (meaning, 'not gonna dew't'). They gave us important Green Button, not difficult aperture lever.

02-13-2015, 10:53 AM   #17
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It will never happen. As proof:

In lieu of a mechanical coupler, they could automate the green button, maybe through a menu setting. So, with M and K lenses, when you hit the shutter button, the camera would actuate the green button for you, then fire the shutter. This approach would require zero space and no new parts.

They will never do this, as their goal is not to increase the value and compatibility of legacy lenses. The fact that we get a green button at all, is the only olive branch we are getting.
02-13-2015, 11:09 AM   #18
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What`s so wrong with the green button? I use it quite often on my K-5, and most of the time the camera is mounted on a tripod when I do. So it's a rather slow procedure anyway, where the green button is no burden. Or am I getting something wrong?
02-13-2015, 11:12 AM - 2 Likes   #19
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QuoteOriginally posted by Tanzer Quote
It will never happen. As proof:

In lieu of a mechanical coupler, they could automate the green button, maybe through a menu setting. So, with M and K lenses, when you hit the shutter button, the camera would actuate the green button for you, then fire the shutter. This approach would require zero space and no new parts.

They will never do this, as their goal is not to increase the value and compatibility of legacy lenses. The fact that we get a green button at all, is the only olive branch we are getting.
Why then is Nikon doing it?

02-13-2015, 11:25 AM - 2 Likes   #20
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I, like a lot of you think they leave it out to sell more DA lenses. IMO, having the coupler wouldn't cut into DA sales any more than A series lenses do. I think their fear of lost profit is a silly one. If they really want to increase modern lens sales, why not ditch K mount all together? Because it would be costly. K mount is an asset. The stop down coupler wouldn't change that.
02-13-2015, 11:34 AM   #21
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QuoteOriginally posted by geomez Quote
I, like a lot of you think they leave it out to sell more DA lenses. IMO, having the coupler wouldn't cut into DA sales any more than A series lenses do. I think their fear of lost profit is a silly one. If they really want to increase modern lens sales, why not ditch K mount all together? Because it would be costly. K mount is an asset. The stop down coupler wouldn't change that.
It was a fear years ago but now, I agree there's little influence iMO.
But technically it isnt as easy as many think it is.
02-13-2015, 12:13 PM   #22
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QuoteOriginally posted by thibs Quote
It was a fear years ago but now, I agree there's little influence iMO.
But technically it isnt as easy as many think it is.


I am exceptionally naïve when it comes to camera engineering and design. All I know is I have some old Pentax film bodies that are tiny with stop down couplers.

02-13-2015, 12:15 PM   #23
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QuoteOriginally posted by geomez Quote
I am exceptionally naïve when it comes to camera engineering and design. All I know is I have some old Pentax film bodies that are tiny with stop down couplers.
That's alright you don't need to be an expert
02-13-2015, 12:17 PM   #24
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QuoteOriginally posted by blende8 Quote
Why then is Nikon doing it?
Because it was the only way to add backwards compatibility. It can also be used as an upsell, because the low end cameras don't have it.
02-13-2015, 12:17 PM   #25
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It seems to me that camera is ready not as mock-up. If the camera is in development, why they say that limited space for aperture coupler?
Is it problem to add it during developing? I don't think so...

That's why I think they have already working sample. All mechanical parts of camera is ready IMO
02-13-2015, 12:27 PM   #26
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QuoteOriginally posted by boriscleto Quote
Because it was the only way to add backwards compatibility.
What's the difference to Pentax that the coupler was the only way?
02-13-2015, 12:31 PM   #27
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QuoteOriginally posted by blende8 Quote
What's the difference to Pentax that the coupler was the only way?
It seems to me that they buried this idea many years ago. There is space in any camera. They found simple excuse.
02-13-2015, 01:14 PM   #28
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QuoteOriginally posted by blende8 Quote
What's the difference to Pentax that the coupler was the only way?
As far as I can tell Nikon DSLRs that have the AI coupler use it as a way to fool the camera into thinking it has lens with a chip in it mounted. When you mount an AI lens to a DSLR with the coupler you have to manually enter the focal length and min/max aperture into the camera. Otherwise the meter won't know how to handle it. Nikon never put electrical contacts on the F-mount until the AF era.

When the *ist D first came out it didn't have any way to use a non-A lens, just like any other 'crippled' KAF2 mount camera. Pentax added stop down metering as a work around. Much less engineering needed than the Nikon solution.
02-13-2015, 01:38 PM - 1 Like   #29
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Forgive my ignorance, but when I mount a Pentax (or any other) manual lens on my NEX-F3 via a simple dumb PK-NEX adapter, as I adjust the aperture, the camera just continuously meters the scene according to the light the lens lets in. I then simply manually focus and shoot.

Would a stop-down coupler enable Pentax lenses without the A setting to behave the same way on a Pentax DSLR (ie no need to use the green button to meter the scene with K or M series lenses, just adjust aperture on the lens, focus and then shoot)?
02-13-2015, 01:59 PM - 1 Like   #30
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QuoteOriginally posted by rawr Quote
Forgive my ignorance, but when I mount a Pentax (or any other) manual lens on my NEX-F3 via a simple dumb PK-NEX adapter, as I adjust the aperture, the camera just continuously meters the scene according to the light the lens lets in. I then simply manually focus and shoot.

Would a stop-down coupler enable Pentax lenses without the A setting to behave the same way on a Pentax DSLR (ie no need to use the green button to meter the scene with K or M series lenses, just adjust aperture on the lens, focus and then shoot)?
Yes -- and moreover, unlike the adapter scenario you described, the aperture would remain wide open until you take the picture. So you would still get the brightest possible viewfinder, for easier focusing.
The coupler tells the camera what setting the aperture ring is at, so the camera can use that plus the amount of light coming in (at wide open) to deduce the correct exposure.

So you get both full-time metering as with adapted lenses (like M42) and wide-open focusing and composing as with K/M lenses.

Last edited by Scintilla; 02-13-2015 at 02:00 PM. Reason: unclear grammar
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