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05-31-2010, 05:58 AM   #1
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Button "base" in K-7?

i dont know if this issue has already discussed, but it is interesting that K-7 has an unused button base.

This is same button basement than that is used earlyer, for example in MZ-3, for depth of field preview button.

K-7 has this basement, but not button on it.

Interesting that they planned to install an button for some purpose into it, but not removed the basement when this button was cancelled... the change has obviously been made in very late phase before the start of production run..

05-31-2010, 07:11 AM   #2
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Yep, that's the first thing I noticed when I laid my hands on my K7 : it's pretty badly placed, right under my middle finger...

I wonder what they nearly put here... AF point selection, maybe, or drive mode?
05-31-2010, 08:23 AM   #3
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Do you mean the bump in the "valley" between the grip and the the lens mount, near the AF assist lamp ? If so, I recall that was determined to be a housing for the electronic aperture actuator. I can't find the thread(s) about it anymore, unfortunately.
05-31-2010, 08:52 AM   #4
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QuoteOriginally posted by RBellavance Quote
Do you mean the bump in the "valley" between the grip and the the lens mount, near the AF assist lamp ? If so, I recall that was determined to be a housing for the electronic aperture actuator. I can't find the thread(s) about it anymore, unfortunately.
Logical place for it, I'm sure, that's where the old stopdown buttons were, yes? A little motor to do the same thing may as well be there, but the main switch seems to serve well enough. If they put a DOF preview switch there, they could free up something for live view or digital preview, I suppose.

05-31-2010, 11:41 AM   #5
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Well, I'm pretty sure it's not the electronic aperture actuator, as:
- it was not here on previous digital models (they all have an electronic aperture actuator, didn't they?)
- on some MZ film camera, there is the same bump (same place, same shape) with a button on it... Like this or (taken from the PentaxForum camera reviews)...
05-31-2010, 11:49 AM   #6
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QuoteOriginally posted by dlacouture Quote
Well, I'm pretty sure it's not the electronic aperture actuator, as:
- it was not here on previous digital models (they all have an electronic aperture actuator, didn't they?)
No, they did not. The electronic aperture actuator is new to the K-7: https://www.pentaxforums.com/forums/pentax-beginners-corner-q/66482-k-7-stran...tml#post668799

Last edited by RBellavance; 06-04-2010 at 09:50 AM.
06-04-2010, 09:32 AM   #7
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Earlyer digital models didnt have it, but last film bodies did. And in film bodies it held an aperture actuator button.

What purpose it was brought again to K-7 is unknown. Maybe next model introduces an button in it for some purpose?
06-05-2010, 04:10 PM   #8
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QuoteOriginally posted by Harald Quote
i dont know if this issue has already discussed
This was discussed more than a year ago. When the first clear images of the K-7 emerged.
QuoteOriginally posted by RBellavance Quote
I recall that was determined to be a housing for the electronic aperture actuator.
Almost correct. It is the aperture lever motor (cf. below).
QuoteOriginally posted by RBellavance Quote
The electronic aperture actuator is new to the K-7
Again, it's a motor. "electronic" isn't the right wording. And yes, it was innovated for the K-7.
QuoteOriginally posted by Harald Quote
last film bodies did [have it]
[...]
What purpose it was brought again to K-7 is unknown
AFAIK, both statements are false.

The purpose is quite simple: The K-7 can open and close the aperture, in a continuous manner, while the imaging sensor remains active, e.g. during movie recording. It can do this for all legacy lenses with an "A"-setting and unlike other brands, does not need special lenses for this feature. According to my own research, the aperture lever motor shifts forth and back between four settings which are about (but not exactly) fully open, f/2.4, f/5.6 and f/11.

It's all written in my blog about a year ago, Falk Lumo: K-7 as a movie camera -- PART II: Controlling video recording

06-05-2010, 05:12 PM   #9
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Thanks for jumping in and clarifying this, Falk !
06-07-2010, 12:16 AM   #10
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Well, how come the Kx doesn't have it, then?
06-07-2010, 03:33 AM   #11
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QuoteOriginally posted by dlacouture Quote
Well, how come the Kx doesn't have it, then?
Well, how come you didn't check first if the K-x has the feature, then?

Using my own words: The K-x can not open and close the aperture, in a continuous manner, while the imaging sensor remains active, e.g. during movie recording.

It computes the aperture prior to the take and sets it to a fixed value just like for a normal photo. E.g., with "Auto" aperture and when shooting a video in a driving car, the K-7 will open up its aperture when driving into a tunnel while the K-x won't. The K-x will just crank up ISO and exposure time.
06-07-2010, 04:46 AM   #12
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Funny, I never thought they could be that different (in my defense, Pentax is not known to advertise their features very well!).

I'm shooting in fixed mode anyway, so I never saw the difference...
06-12-2010, 07:49 AM   #13
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QuoteOriginally posted by falconeye Quote
Well, how come you didn't check first if the K-x has the feature, then?

Using my own words: The K-x can not open and close the aperture, in a continuous manner, while the imaging sensor remains active, e.g. during movie recording.

It computes the aperture prior to the take and sets it to a fixed value just like for a normal photo. E.g., with "Auto" aperture and when shooting a video in a driving car, the K-7 will open up its aperture when driving into a tunnel while the K-x won't. The K-x will just crank up ISO and exposure time.
This explanation is weird, because other Pentax cameras, for example K-20 has liveview, which is mechanically same as taking video. In live view you just do not save the video flow from sensor. And K-20 do not need this bulge. So I dont believe your explanation.

So I do not undestand what is this "continuous manner" means. As far as I understand, K-7 aperture works jus as it has been working decades. And same manner as earlyer digital models. for example K-20 which is liveview capable.

So what exactly means "continuous manner"????

When lever or button or shutter release button is pressed, aperture stays closed until it is opened again. Time how long it stays closed, is determined by user or algorithms. What is different in K-7 and why this difference is needing an bulge into very same place other cameras have aperture actuator button?

And believe that I know principles of SRLs very very well.... be precise.
06-12-2010, 04:08 PM   #14
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QuoteOriginally posted by Harald Quote
So I dont believe your explanation.

So I do not undestand what is this "continuous manner" means.
Did you post to:
1. tell me you don't believe what I post?
2. or to ask a question?

In case #1 I cannot help you.

In case #2 I ask you to be precise in your question ... Otherwise, the word "continuous" is plain English I I wouldn't know how to explain it any better than a dictionary does


Maybe one more thing though ...

The K-7's aperture lever motor is audible when it works. A noise I am sure you'll never hear from a K20D, a K-x or any prior SLR...
06-14-2010, 03:00 AM   #15
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By "continuous", Falconeye means that the K7 can change the aperture value during the video recording.
And the Kx is not able to do it "live", so it only uses a preset aperture value.

I don't really understand what prevented the old mechanism from doing "live" adjustements, but if Pentax had to update it, must be for a good reason...
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