[New Product Story Vol.8] Aperture coupler is (sorta) back!

**UncleVanya** · 12-27-2020, 09:30 AM

Originally posted by repaap

What GPS?

The one in the k-3 II I assume which isn’t in the K-3 iii.

I bought my k-3 rather than a k-3 II because I wanted a built in flash.

repaap · 12-27-2020, 10:12 AM

Originally posted by UncleVanya

The one in the k-3 II I assume which isn’t in the K-3 iii.

I bought my k-3 rather than a k-3 II because I wanted a built in flash.

Thanks! I had K-3 because I wanted immediate upgrade to my K-7. I was early adopter. It was a bummer that K-3 II had gps. Now I have K-1 and it does have GPS. I was lusting after Astro shots. I’v done those about 3 times. And used GPS for geotag propably couple times more.

About that flash. I prefer proper flash over popup and this is why I won’t miss that at all. I have Eli chrome quadra so I can take em with me or settle for fgz360II(have to get one more of those actually. Yes, I use them also in rain. And that is why.

stevebrot · 12-27-2020, 01:52 PM

Originally posted by pschlute

On the new K3III the shutter speed will show in TAv mode. In Av mode I am not sure. On current camera models it does but that is because the camera only shoots wide open in Av mode.

According to the Pentax, input of the aperture allows for additional exposure modes. The information at this point is contradictory. Either the aperture information is used for exposure purposes or it isn't. ~~If aperture is known, there is no need to meter stopped down. I would expect that the stop-down metering is needed for lenses having pre-set or manual apertures.~~ Edit: Wishful thinking on my part...of course the offset from wide open is required information.

Steve

stevebrot · 12-27-2020, 01:57 PM

Originally posted by Breakfastographer

Seems like there's still no word on whether focal lengths shorter than 10mm are now fully compatible.

I did not notice...8mm is currently supported. Is there reason to believe the interface does not support single digit focal lengths?

Steve

Mistral75 · 12-27-2020, 02:50 PM - **1 Like**

Originally posted by stevebrot

(...) If aperture is known, there is no need to meter stopped down. (...)

The camera has to know both the full aperture and the chosen aperture not to need to meter stopped down.

Breakfastographer · 12-27-2020, 03:31 PM

Originally posted by stevebrot

I did not notice...8mm is currently supported.

Sorry, as of which camera?

Originally posted by stevebrot

Is there reason to believe the interface does not support single digit focal lengths?

For the longest time, IBIS wouldn't work correctly with <10mm FL (and could not manually be set for it!), and the EXIF field for focal length would just be left blank or set to 10mm if FL was <10mm. This would then also trip up third party lens corrections, among other things (correcting 8mm images for 10mm distortions, say - which in UWA really isn't ideal). I remember seeing scripts for bulk correction of EXIF values to fix some of these problems.

**Serkevan** · 12-27-2020, 04:25 PM - **1 Like**

Originally posted by Breakfastographer

Sorry, as of which camera?

The K-1 lets you select 8 mm. Whether it works well or not, I can't say - my widest lens is 20 mm.

Breakfastographer · 12-27-2020, 04:36 PM

Originally posted by Serkevan

The K-1 lets you select 8 mm. Whether it works well or not, I can't say - my widest lens is 20 mm.

Thank you, Serkevan, glad to know they fixed that. I have reasonable hope, then, that they may have carried that change forward to the KP and K-3 III. I mean, it would make sense to fix it once and for all.

pschlute · 12-27-2020, 05:28 PM

Originally posted by stevebrot

The information at this point is contradictory. Either the aperture information is used for exposure purposes or it isn't.

The way I read it from both the video and the article is that the input of the aperture via the thumbwheel is both optional and is for exif information purposes only. The menu item is called Aperture Info Record. The video shows that when in Av mode with the option selected on , the Av value flashes - presumably to indicate that it is for information purposes only.

The article describes the functioning in Av and TAv mode, describing it as "Designed to automatically perform closed-down metering at the moment of shutter release".

**UncleVanya** · 12-27-2020, 05:36 PM

Originally posted by stevebrot

According to the Pentax, input of the aperture allows for additional exposure modes. The information at this point is contradictory. Either the aperture information is used for exposure purposes or it isn't. If aperture is known, there is no need to meter stopped down. I would expect that the stop-down metering is needed for lenses having pre-set or manual apertures.

Steve

If I give the camera the f stop I’m using but it has no clue what wide open aperture of my lens is how would it meter at all? It wouldn’t know how many stops from wide open that aperture is. I’m not following something Steve.

stevebrot · 12-27-2020, 05:37 PM - **1 Like**

Originally posted by Breakfastographer

Sorry, as of which camera?

K-3 and newer for sure.

Addendum: For me, K10D used with the Rokinon 8/3.5 Fisheye (https://www.flickr.com/photos/28796087@N02/albums/72157697287532804 no scripts run or edits to the EXIF except for final image.)

Steve

stevebrot · 12-27-2020, 05:54 PM

Originally posted by UncleVanya

If I give the camera the f stop I’m using but it has no clue what wide open aperture of my lens is how would it meter at all? It wouldn’t know how many stops from wide open that aperture is. I’m not following something Steve.

I think you are probably right and I have probably been not thinking clearly due to wishful thinking. Yes, the system needs to know the offset from maximum aperture to calculate the shutter speed unless the lens is at maximum aperture.

Steve

stevebrot · 12-27-2020, 05:55 PM

Originally posted by pschlute

The way I read it from both the video and the article is that the input of the aperture via the thumbwheel is both optional and is for exif information purposes only. The menu item is called Aperture Info Record. The video shows that when in Av mode with the option selected on , the Av value flashes - presumably to indicate that it is for information purposes only.

The article describes the functioning in Av and TAv mode, describing it as "Designed to automatically perform closed-down metering at the moment of shutter release".

I recant...

Steve

Breakfastographer · 12-27-2020, 05:56 PM

Withdrawn in light of further discussion.

**UncleVanya** · 12-27-2020, 06:02 PM

Originally posted by stevebrot

I think you are probably right and I have probably been not thinking clearly due to wishful thinking. Yes, the system needs to know the offset from maximum aperture to calculate the shutter speed unless the lens is at maximum aperture.

Steve

Now if we could input the max f stop in some version of this and then dialed in our manual aperture I’d see it working quite well but pretty easy for end users to forget to switch the f stop and get poor exposures.

It is tantalizing to think of ways to leverage these new features.

12-27-2020, 01:52 PM	#93
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by pschlute On the new K3III the shutter speed will show in TAv mode. In Av mode I am not sure. On current camera models it does but that is because the camera only shoots wide open in Av mode. According to the Pentax, input of the aperture allows for additional exposure modes. The information at this point is contradictory. Either the aperture information is used for exposure purposes or it isn't. ~~If aperture is known, there is no need to meter stopped down. I would expect that the stop-down metering is needed for lenses having pre-set or manual apertures.~~ Edit: Wishful thinking on my part...of course the offset from wide open is required information. Steve Last edited by stevebrot; 12-27-2020 at 06:05 PM.

12-27-2020, 05:37 PM - 1 Like	#101
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Breakfastographer Sorry, as of which camera? K-3 and newer for sure. Addendum: For me, K10D used with the Rokinon 8/3.5 Fisheye (https://www.flickr.com/photos/28796087@N02/albums/72157697287532804 no scripts run or edits to the EXIF except for final image.) Steve Last edited by stevebrot; 12-27-2020 at 06:02 PM.

12-27-2020, 05:56 PM	#104
Breakfastographer Pentaxian Join Date: Nov 2018 Posts: 673	Withdrawn in light of further discussion. Last edited by Breakfastographer; 12-27-2020 at 06:37 PM.

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12-27-2020, 09:30 AM	#91
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,398	Originally posted by repaap What GPS? The one in the k-3 II I assume which isn’t in the K-3 iii. I bought my k-3 rather than a k-3 II because I wanted a built in flash.

12-27-2020, 10:12 AM	#92
repaap Pentaxian Join Date: Oct 2010 Photos: Gallery \| Albums Posts: 6,242	Originally posted by UncleVanya The one in the k-3 II I assume which isn’t in the K-3 iii. I bought my k-3 rather than a k-3 II because I wanted a built in flash. Thanks! I had K-3 because I wanted immediate upgrade to my K-7. I was early adopter. It was a bummer that K-3 II had gps. Now I have K-1 and it does have GPS. I was lusting after Astro shots. I’v done those about 3 times. And used GPS for geotag propably couple times more. About that flash. I prefer proper flash over popup and this is why I won’t miss that at all. I have Eli chrome quadra so I can take em with me or settle for fgz360II(have to get one more of those actually. Yes, I use them also in rain. And that is why.

12-27-2020, 01:57 PM	#94
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Breakfastographer Seems like there's still no word on whether focal lengths shorter than 10mm are now fully compatible. I did not notice...8mm is currently supported. Is there reason to believe the interface does not support single digit focal lengths? Steve

12-27-2020, 02:50 PM - 1 Like	#95
Mistral75 Pentaxian Join Date: Feb 2009 Location: Paris, France Posts: 7,527	Originally posted by stevebrot (...) If aperture is known, there is no need to meter stopped down. (...) The camera has to know both the full aperture and the chosen aperture not to need to meter stopped down.

12-27-2020, 03:31 PM	#96
Breakfastographer Pentaxian Join Date: Nov 2018 Posts: 673	Originally posted by stevebrot I did not notice...8mm is currently supported. Sorry, as of which camera? Originally posted by stevebrot Is there reason to believe the interface does not support single digit focal lengths? For the longest time, IBIS wouldn't work correctly with <10mm FL (and could not manually be set for it!), and the EXIF field for focal length would just be left blank or set to 10mm if FL was <10mm. This would then also trip up third party lens corrections, among other things (correcting 8mm images for 10mm distortions, say - which in UWA really isn't ideal). I remember seeing scripts for bulk correction of EXIF values to fix some of these problems.

12-27-2020, 04:25 PM - 1 Like	#97
Serkevan Site Supporter Join Date: May 2019 Photos: Albums Posts: 5,976 Original Poster	Originally posted by Breakfastographer Sorry, as of which camera? The K-1 lets you select 8 mm. Whether it works well or not, I can't say - my widest lens is 20 mm.

12-27-2020, 04:36 PM	#98
Breakfastographer Pentaxian Join Date: Nov 2018 Posts: 673	Originally posted by Serkevan The K-1 lets you select 8 mm. Whether it works well or not, I can't say - my widest lens is 20 mm. Thank you, Serkevan, glad to know they fixed that. I have reasonable hope, then, that they may have carried that change forward to the KP and K-3 III. I mean, it would make sense to fix it once and for all.

12-27-2020, 05:28 PM	#99
pschlute Moderator Loyal Site Supporter Join Date: Mar 2007 Location: Surrey, UK Photos: Gallery Posts: 8,198	Originally posted by stevebrot The information at this point is contradictory. Either the aperture information is used for exposure purposes or it isn't. The way I read it from both the video and the article is that the input of the aperture via the thumbwheel is both optional and is for exif information purposes only. The menu item is called Aperture Info Record. The video shows that when in Av mode with the option selected on , the Av value flashes - presumably to indicate that it is for information purposes only. The article describes the functioning in Av and TAv mode, describing it as "Designed to automatically perform closed-down metering at the moment of shutter release".

12-27-2020, 05:36 PM	#100
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,398	Originally posted by stevebrot According to the Pentax, input of the aperture allows for additional exposure modes. The information at this point is contradictory. Either the aperture information is used for exposure purposes or it isn't. If aperture is known, there is no need to meter stopped down. I would expect that the stop-down metering is needed for lenses having pre-set or manual apertures. Steve If I give the camera the f stop I’m using but it has no clue what wide open aperture of my lens is how would it meter at all? It wouldn’t know how many stops from wide open that aperture is. I’m not following something Steve.

12-27-2020, 05:54 PM	#102
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by UncleVanya If I give the camera the f stop I’m using but it has no clue what wide open aperture of my lens is how would it meter at all? It wouldn’t know how many stops from wide open that aperture is. I’m not following something Steve. I think you are probably right and I have probably been not thinking clearly due to wishful thinking. Yes, the system needs to know the offset from maximum aperture to calculate the shutter speed unless the lens is at maximum aperture. Steve

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12-27-2020, 05:55 PM	#103
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by pschlute The way I read it from both the video and the article is that the input of the aperture via the thumbwheel is both optional and is for exif information purposes only. The menu item is called Aperture Info Record. The video shows that when in Av mode with the option selected on , the Av value flashes - presumably to indicate that it is for information purposes only. The article describes the functioning in Av and TAv mode, describing it as "Designed to automatically perform closed-down metering at the moment of shutter release". I recant... Steve

12-27-2020, 06:02 PM	#105
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,398	Originally posted by stevebrot I think you are probably right and I have probably been not thinking clearly due to wishful thinking. Yes, the system needs to know the offset from maximum aperture to calculate the shutter speed unless the lens is at maximum aperture. Steve Now if we could input the max f stop in some version of this and then dialed in our manual aperture I’d see it working quite well but pretty easy for end users to forget to switch the f stop and get poor exposures. It is tantalizing to think of ways to leverage these new features.