Movie mode shutter/mirror actuating on record


SteveLedger

Link Posted 01/05/2014 - 21:38
When using the K-50's movie mode I'm finding that when I press the shutter release to start recording the mirror flips up again and the shutter opens, then when I press the shutter release to stop recording it flips down and up again. This makes no sense to me as it's already flipped up when selecting movie mode with the mode dial.
It almost sounds like it's in still capture mode.
Strangely, on one occasion it did silently start recording and silently stopped. I had made no changes except to the Aperture for each clip! So what caused it to suddenly change to silent rec/stop I have no idea. I was unable to get a repeat of this, even immediately after with the same setting and pointed at the same subject.
Doesn't matter if I'm using AF or M focus.
I've updated to the latest 1.02 firmware, no change.
The K-7 doesn't do this, pressing the shutter release just silently starts recording.

What have I missed? Is this normal? Do other K-50 users find this immensely annoying, is the K-30 the same? What about the K-3 - does this happen on the flagship as well?

McGregNi

Link Posted 01/05/2014 - 21:52
On the K7 / K5 series models this behaviour is related to the Movie Autofocus mode selected - this is controlled in the menu. It depends on whether you choose a phase detection or contrast type autofocus (phase type will flip the mirror to allow the AF snesors to work, a quicker AF response). Maybe your camera is set for this? Its worth checking. If your shutter button is set for AF activate then this will trip the mirror as described. (Ending recording with the shutter button does sometimes also flip the mirror I have found).

Contrast detect AF is probably preferable for video work, due to the uninterruped screen view, and fine tuning can be done with Quick-shift on DA lenses. Also, there's a logic for video to de-activating AF on the shutter button and using this just to start/stop recording, and use the AF button specifically when you want to focus.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Last Edited by McGregNi on 01/05/2014 - 21:53

SteveLedger

Link Posted 01/05/2014 - 21:55
As mentioned, doesn't matter if AF or Manual focus is used. Same thing happens.
Also, this happens after button press focusing when in AF mode.
Back Button AF also makes no difference.
In any case, those CDAF/PDAF options don't exist for the K-50.
Last Edited by SteveLedger on 01/05/2014 - 22:01

davidstorm

Link Posted 01/05/2014 - 21:57
Not sure if you are right on this Nigel as the OP states 'Doesn't matter if I'm using AF or M focus' and also I didn't think AF when recording was possible on a K-5 or a K-7? Anyway, the OP has a K-50, I'm not sure what the AF possibilities with video are on this model.

Regards
David
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McGregNi

Link Posted 01/05/2014 - 22:15
I know David, It's not a definituve answer, just raising some possibilities to explore really. At least the OP can check these AF settings to rule anything out. Do we have any K50 video shooters out there to help? That model is a development of the K30, so I'd expect some continuity on from that older models functioning as well.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Last Edited by McGregNi on 01/05/2014 - 22:17

McGregNi

Link Posted 01/05/2014 - 22:18
Only just seen your reply there sledger - thanks for clarifying that.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

richandfleur

Link Posted 01/05/2014 - 22:34
sledger wrote:
When using the K-50's movie mode I'm finding that when I press the shutter release to start recording the mirror flips up again and the shutter opens, then when I press the shutter release to stop recording it flips down and up again.

It's a known behaviour. I don't think it's wrong as such (from Pentax's view), it's just that it makes no sense at all.

In extreme examples, I know people who had wanted to use their device for studio / concert recording who had to avoid this because of the sheer noise of the shutter which meaninglessly fired at the start of every clip.

On the flip side, I had a funny experience with this at a friends child's birthday part, where no one knew I was video recording. They assumed I was taking photos and maybe taking a long time to compose the shot etc, which lead to some really candid moments. The K-30 looked like a 'camera' to those in the room who associated a DSLR with pictures, and it made a camera sound like a photo was being taken, only it was actually the start and end of a video piece.

I'm not sure on the flagship K3 but I wouldn't be surprised if it did. It essentially has the same video features as the K-30/K-50 range. Looking at the discussions on Pentax firmware hacking it looks like Pentax have changed basis's a lot recently, with the K-5 series, the Pentax Q and the K-50/K-3 all having different processes and being written in different coding languages. There appear to be quite major differences between the ages and models, more than is perhaps apparent from the similar visual menus.
Last Edited by richandfleur on 01/05/2014 - 22:35

SteveLedger

Link Posted 01/05/2014 - 22:42
OK, but - it still doesn't answer why it actually did silently record and stop on one occasion yesterday.
When it happened I thought "Oh! maybe it's related to acceptable settings for the current lighting conditions which are spot on this time?"
But no, repeating the same conditions didn't not repeat the silent mode.
I've almost depleted the battery trying out every different setting and lighting scenario I can think of.
This 'change' then is a senseless as Movie SR is when there's a perfectly good mechanical SR built right into the body.

McGregNi

Link Posted 01/05/2014 - 22:44
So what kind of Auto Focus technique does the K50 use then? Is it not phase detect type causing this mirror action?
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver

richandfleur

Link Posted 01/05/2014 - 23:15
McGregNi wrote:
So what kind of Auto Focus technique does the K50 use then? Is it not phase detect type causing this mirror action?

The unit will focus with a half press, but only fire the shutter when you press fully to start recording. It's in live view only right from the selection of video mode, and will focus (relatively silently) in this mode just like live view during stills modes.

SteveLedger

Link Posted 01/05/2014 - 23:54
Manually focusing [using FP] doesn't make any difference, so focus mode has nothing to do with it I think.
Only reason I bought the K-50 is for better stills outdoors in full sun. I have a K-01 which is useless outside. The K-01 and K-50 movie IQ is the same, so I'll not bother with the K-50 for movies, it's too annoying.

SteveLedger

Link Posted 09/05/2014 - 10:55
Success!!!
For reasons only known to Pentax engineers, the shutter/mirror flip on start rec and stop rec does not happen when the aperture is set to F4
Any other aperture and it will flip. No other setting affects this phenomenon.
So, for silent start/stop video recording - set aperture to F4.
I'll test some other lenses when I get a chance though my main lens for general use on the the K-50 is the Tamron 17-50mm 2.8.

SteveLedger

Link Posted 09/05/2014 - 12:47
UPDATE: For the 18-55mm DA L WR, F3.5 is the magic aperture for silent stop/start movie capture.

sbrads

Link Posted 09/05/2014 - 14:15
sledger wrote:
UPDATE: For the 18-55mm DA L WR, F3.5 is the magic aperture for silent stop/start movie capture.

Well well, I never knew that. I just played with a Sigma 17-50/2.8 and that doesn't do the mirror flip at f4.0 on the K-30.

SteveLedger

Link Posted 09/05/2014 - 20:29
Unless there's a sound technical reason, I'd say we're looking at a software bug.
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