K-S2 automatically stops down in liveview

palador · 06-08-2016, 11:28 AM

Hi everyone,

I have a K-S2 and I like to focus manually in liveview all the time. I use old M lenses and newer DA ones. I always wondered why DA lenses are harder to focus than my old primes. Today, I figured out why:

In liveview, the camera always stops down the same amount, about 1-2 EV. This behavior doesn't depend on any settings or the current light (The aperture looks the same in bright daylight and in a dark room).

Using lenses with an aperturering, I can workaround by shooting in M mode and selecting the aperture with the ring. With DA lenses I could use the "optical preview" function to open my lens.

Is there a setting to fix this? Btw, I'm have FW 1.11 and tried to reset all settings, already.

ps: sry for bad english, I already asked this question in a german forum, but nobody was able to help me there

**UncleVanya** · 06-08-2016, 11:42 AM

There are some other threads about this. I thought my DA 40 always stopped down but then I found on occasion it doesn't. I'm not entirely sure what causes the difference but I can tell you you can get slightly different behavior than expected - sometimes it is wide open sometimes it isn't. I'm lost as to why it differs. I generally expect it to be about f/4 and yes that makes focusing at an f stop wider hard.

Na Horuk · 06-08-2016, 12:01 PM

Pentax cameras automatically stop down in live view. I think this is done for two reasons: a) protect the sensor from heat and too much light (digital sensors can be damaged by this), and b) for composition (it is difficult to compose the shot if most of the frame is blurry, stopping down makes this much easier)

Is this perfect? No. Is this needed to keep the camera running normally? Probably.

What you can do is press the Digital zoom button (Info or Ok, depending on camera), which opens the lens' aperture for the duration of the zoom. This is a great focusing aid, especially when done together with focus peaking. (I have FP programmed to red button on my K-01, which is always in live view).

---------- Post added 8th Jun 2016 at 21:05 ----------

The biggest annoyance with camera automatically changing apertures even when not taking photos is the sound - people sometimes think I am taking photos of them from behind, but I am just walking, which happens to point the camera from dark to bright areas, and triggers the aperture blades change. Other problem is when you want to shoot with aperture wider than what camera is showing you; which gives you wrong sense of security regarding focus, DoF.
Another thing to mention is that the camera does not exhibit this behaviour with lenses that have manual aperture.
Fairly sure this happens with all cameras after K-01. A solution for Pentax would be to add a variable ND filter onto the sensor, as some mirrorless cameras already have. But for a DSLR, this doesn't make much sense. However, camera should always stop down or open up the aperture to the selected f-number once the photo exposure starts

swanlefitte · 06-08-2016, 01:21 PM

Use TAv with auto iso set as low as you need it. Can go as low as 125 if you have menu set to 1/3 steps ev. The screen stays bright.

**UncleVanya** · 06-08-2016, 01:30 PM

Originally posted by swanlefitte

Use TAv with auto iso set as low as you need it. Can go as low as 125 if you have menu set to 1/3 steps ev. The screen stays bright.

I don't understand how this relates to the issue - the TAv or Av mode doesn't change the aperture behavior in LiveView - you can set wide open on Av or TAv and it still does this. Only with a manual aperture ring can you force different behavior. The odd thing is that it isn't fully consistent. The aperture seems consistent in all lighting at times but then sometimes it isn't - it opens more than normal for reasons unexpected.

palador · 06-08-2016, 02:16 PM

It seems that the behavior differs a bit between cameras. I also remember my K-01 which also stopped down, but not fixed as my K-S2 does but depending on the light. I do not remember how it was in zoomed mode. However, the K-S2 stops down to a fixed aperture and doesn't care how much light there actually is. And it stays that way in zoomed mode.

And I'm not sure whether it's all about protection, because I can use my M 50 1.4 without issues and it doesn't harm the sensor even pointed directly to the sun fully open.

Maybe it's because easier composition or because liveview autofocus works better this way. But the aperture should open as soon MF is selected or the liveview is zoomed.

I wanted to try an older firmeware version, because one of the first updates improved LV Autofocus performance. Maybe they introduced this issue there. But I can't find the initial firmeware anywhere. Does anyone know a place where I can download all FW versions for my camera?

Na Horuk · 06-08-2016, 02:30 PM

Originally posted by palador

And I'm not sure whether it's all about protection, because I can use my M 50 1.4 without issues and it doesn't harm the sensor even pointed directly to the sun fully open.

Well, it hasn't harmed the sensor yet. It might just reduce its overall sensitivity, life span. But I know there were cases where people's DSLR got damaged due to taking highly overexposed photos (sunlight, fast lens). You can google for this if you want. I never heard of a case of this happening to a Pentax camera because of Live view, though

stevebrot · 06-08-2016, 02:49 PM

Originally posted by UncleVanya

I don't understand how this relates to the issue - the TAv or Av mode doesn't change the aperture behavior in LiveView - you can set wide open on Av or TAv and it still does this.

Give it a try. The suggestion is a well-known hack and useful if you want to evaluate DOF/bokeh wide open.

Steve

stevebrot · 06-08-2016, 02:49 PM

Originally posted by palador

It seems that the behavior differs a bit between cameras. I also remember my K-01 which also stopped down

...and every model since.

Steve

swanlefitte · 06-08-2016, 02:56 PM

The workaround of TAv is that the only difference from M is auto Iso. So you need to prevent auto by restricting it. If camera is set to half steps auto Iso only goes 100-200 but at third steps it's 100-125. In manual you could say be set to f2. 8 8000 and ISO100 but 125 is close.

---------- Post added 06-08-16 at 03:15 PM ----------

I was a little confused. In custom menu 1 set half steps of third steps. In custom menu 2 set sensitivity to as ev steps. At half steps auto can be 100-140. Flash synch will be 1/160 or 1/180 which can matter when mixing flash with ambient in the odd occasion.

palador · 06-08-2016, 03:05 PM

I just tried the TAv mode, but with the K-S2 it doesn't work. The only two things which work are
1. set the aperture using the ring on the lens (doen't work with DA lenses)
2. use the 'optical preview' button (but pressing it while focusing isn't that comfortable)

stevebrot · 06-08-2016, 06:01 PM

Originally posted by palador

I just tried the TAv mode, but with the K-S2 it doesn't work. The only two things which work are
1. set the aperture using the ring on the lens (doen't work with DA lenses)
2. use the 'optical preview' button (but pressing it while focusing isn't that comfortable)

Does it open up in magnified live view?

Steve

**UncleVanya** · 06-08-2016, 10:08 PM

Originally posted by stevebrot

Give it a try. The suggestion is a well-known hack and useful if you want to evaluate DOF/bokeh wide open.

Steve

TAv or M?

palador · 06-09-2016, 12:08 AM

Originally posted by stevebrot

Does it open up in magnified live view?

No

Is there someone else owning a K-S2 to confirm this issue?

swanlefitte · 06-09-2016, 01:51 AM

I don't think I am clear on what you are saying. You mean the screen is dark in live view even when the scene is exposed correctly so the pictures come out looking 2 ev brighter when reviewing? If so that doesn't happen for me. The live view and the review are the same brightness.

06-08-2016, 11:28 AM	#1
palador New Member Join Date: Jun 2016 Posts: 8	K-S2 automatically stops down in liveview Hi everyone, I have a K-S2 and I like to focus manually in liveview all the time. I use old M lenses and newer DA ones. I always wondered why DA lenses are harder to focus than my old primes. Today, I figured out why: In liveview, the camera always stops down the same amount, about 1-2 EV. This behavior doesn't depend on any settings or the current light (The aperture looks the same in bright daylight and in a dark room). Using lenses with an aperturering, I can workaround by shooting in M mode and selecting the aperture with the ring. With DA lenses I could use the "optical preview" function to open my lens. Is there a setting to fix this? Btw, I'm have FW 1.11 and tried to reset all settings, already. ps: sry for bad english, I already asked this question in a german forum, but nobody was able to help me there

06-08-2016, 12:01 PM	#3
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	Pentax cameras automatically stop down in live view. I think this is done for two reasons: a) protect the sensor from heat and too much light (digital sensors can be damaged by this), and b) for composition (it is difficult to compose the shot if most of the frame is blurry, stopping down makes this much easier) Is this perfect? No. Is this needed to keep the camera running normally? Probably. What you can do is press the Digital zoom button (Info or Ok, depending on camera), which opens the lens' aperture for the duration of the zoom. This is a great focusing aid, especially when done together with focus peaking. (I have FP programmed to red button on my K-01, which is always in live view). ---------- Post added 8th Jun 2016 at 21:05 ---------- The biggest annoyance with camera automatically changing apertures even when not taking photos is the sound - people sometimes think I am taking photos of them from behind, but I am just walking, which happens to point the camera from dark to bright areas, and triggers the aperture blades change. Other problem is when you want to shoot with aperture wider than what camera is showing you; which gives you wrong sense of security regarding focus, DoF. Another thing to mention is that the camera does not exhibit this behaviour with lenses that have manual aperture. Fairly sure this happens with all cameras after K-01. A solution for Pentax would be to add a variable ND filter onto the sensor, as some mirrorless cameras already have. But for a DSLR, this doesn't make much sense. However, camera should always stop down or open up the aperture to the selected f-number once the photo exposure starts Last edited by Na Horuk; 06-08-2016 at 01:24 PM.

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06-08-2016, 11:42 AM	#2
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,450	There are some other threads about this. I thought my DA 40 always stopped down but then I found on occasion it doesn't. I'm not entirely sure what causes the difference but I can tell you you can get slightly different behavior than expected - sometimes it is wide open sometimes it isn't. I'm lost as to why it differs. I generally expect it to be about f/4 and yes that makes focusing at an f stop wider hard.

06-08-2016, 01:21 PM	#4
swanlefitte Pentaxian Join Date: May 2015 Location: Minneapolis Photos: Gallery Posts: 4,068	Use TAv with auto iso set as low as you need it. Can go as low as 125 if you have menu set to 1/3 steps ev. The screen stays bright.

06-08-2016, 01:30 PM	#5
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,450	Originally posted by swanlefitte Use TAv with auto iso set as low as you need it. Can go as low as 125 if you have menu set to 1/3 steps ev. The screen stays bright. I don't understand how this relates to the issue - the TAv or Av mode doesn't change the aperture behavior in LiveView - you can set wide open on Av or TAv and it still does this. Only with a manual aperture ring can you force different behavior. The odd thing is that it isn't fully consistent. The aperture seems consistent in all lighting at times but then sometimes it isn't - it opens more than normal for reasons unexpected.

06-08-2016, 02:16 PM	#6
palador New Member Join Date: Jun 2016 Posts: 8 Original Poster	It seems that the behavior differs a bit between cameras. I also remember my K-01 which also stopped down, but not fixed as my K-S2 does but depending on the light. I do not remember how it was in zoomed mode. However, the K-S2 stops down to a fixed aperture and doesn't care how much light there actually is. And it stays that way in zoomed mode. And I'm not sure whether it's all about protection, because I can use my M 50 1.4 without issues and it doesn't harm the sensor even pointed directly to the sun fully open. Maybe it's because easier composition or because liveview autofocus works better this way. But the aperture should open as soon MF is selected or the liveview is zoomed. I wanted to try an older firmeware version, because one of the first updates improved LV Autofocus performance. Maybe they introduced this issue there. But I can't find the initial firmeware anywhere. Does anyone know a place where I can download all FW versions for my camera?

06-08-2016, 02:30 PM	#7
Na Horuk Veteran Member Join Date: Feb 2012 Location: Slovenia, probably Photos: Gallery \| Albums Posts: 11,186	Originally posted by palador And I'm not sure whether it's all about protection, because I can use my M 50 1.4 without issues and it doesn't harm the sensor even pointed directly to the sun fully open. Well, it hasn't harmed the sensor yet. It might just reduce its overall sensitivity, life span. But I know there were cases where people's DSLR got damaged due to taking highly overexposed photos (sunlight, fast lens). You can google for this if you want. I never heard of a case of this happening to a Pentax camera because of Live view, though

06-08-2016, 02:49 PM	#8
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by UncleVanya I don't understand how this relates to the issue - the TAv or Av mode doesn't change the aperture behavior in LiveView - you can set wide open on Av or TAv and it still does this. Give it a try. The suggestion is a well-known hack and useful if you want to evaluate DOF/bokeh wide open. Steve

06-08-2016, 02:49 PM	#9
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by palador It seems that the behavior differs a bit between cameras. I also remember my K-01 which also stopped down ...and every model since. Steve

06-08-2016, 02:56 PM	#10
swanlefitte Pentaxian Join Date: May 2015 Location: Minneapolis Photos: Gallery Posts: 4,068	The workaround of TAv is that the only difference from M is auto Iso. So you need to prevent auto by restricting it. If camera is set to half steps auto Iso only goes 100-200 but at third steps it's 100-125. In manual you could say be set to f2. 8 8000 and ISO100 but 125 is close. ---------- Post added 06-08-16 at 03:15 PM ---------- I was a little confused. In custom menu 1 set half steps of third steps. In custom menu 2 set sensitivity to as ev steps. At half steps auto can be 100-140. Flash synch will be 1/160 or 1/180 which can matter when mixing flash with ambient in the odd occasion.

06-08-2016, 03:05 PM	#11
palador New Member Join Date: Jun 2016 Posts: 8 Original Poster	I just tried the TAv mode, but with the K-S2 it doesn't work. The only two things which work are 1. set the aperture using the ring on the lens (doen't work with DA lenses) 2. use the 'optical preview' button (but pressing it while focusing isn't that comfortable)

06-08-2016, 06:01 PM	#12
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by palador I just tried the TAv mode, but with the K-S2 it doesn't work. The only two things which work are 1. set the aperture using the ring on the lens (doen't work with DA lenses) 2. use the 'optical preview' button (but pressing it while focusing isn't that comfortable) Does it open up in magnified live view? Steve

06-08-2016, 10:08 PM	#13
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,450	Originally posted by stevebrot Give it a try. The suggestion is a well-known hack and useful if you want to evaluate DOF/bokeh wide open. Steve TAv or M?

06-09-2016, 12:08 AM	#14
palador New Member Join Date: Jun 2016 Posts: 8 Original Poster	Originally posted by stevebrot Does it open up in magnified live view? No Is there someone else owning a K-S2 to confirm this issue?

06-09-2016, 01:51 AM	#15
swanlefitte Pentaxian Join Date: May 2015 Location: Minneapolis Photos: Gallery Posts: 4,068	I don't think I am clear on what you are saying. You mean the screen is dark in live view even when the scene is exposed correctly so the pictures come out looking 2 ev brighter when reviewing? If so that doesn't happen for me. The live view and the review are the same brightness.