[Tord]

Hi all,

My wife still has a mint K30, rarely used, but planned to use it today, shooting some birds over at the pond.

But something is amiss: Shooting LV works totally normally, the exposure being spot on, but that is not true for normal shots!

AF-S images come out about 5 EV underexposed.

No problem with the lens (a mint 55-300), and to be doubly sure I tried it on my even older K-x, no issues what-so-ever, and she tried my DA40 with the same issues as with the zoom!

[swanlefitte]

My guess would be live view is using matrix metering measuring light from around the whole sensor.
Using the viewfinder is probably set to spot meter and using the light from one spot. If you focus on the brightest spot, such as the sky or a white flower, everything darker is underexposed. The one spot that was focused on should be properly exposed.

[carlb]

Sounds like the dreaded aperture block failure.

[Unregistered User 8]

Hi Tord, it does sound like the aperture block issue.
Check the link below to confirm if this is your problem. Good luck.

Detection of aperture block/diaphragm-block failure/stuck solenoid K-30, K-50, K500 - PentaxForums.com

[swanlefitte]

Liveview won't make a failed block work. It would be pure coincidence the aperture didn't open everytime while using the viewfinder and at the same time always working when using liveview.
But 5 stops is f/4 to f/22. Or a shutter of 125 to 4000. The exif between the images would reveal alot. Did the camera expose properly and fail in which case the exif will be similar or did the camera meter differently and work in which case the settings should be about 5ev different.

[photogem]

A typical sign for a stuck solenoid:
Often for quite a while it seems to work in LV normally, actually it ain't perfect:
When you have it switched on, turn in to look into the lens you can see that in the moment you switch to LV the aperture closes to the maximum of the lens while it should be f4,0! So metering is not exact but the photo turns out better, i.e. not underexposed.

Check HERE how to make sure it's the solenoid!

Then you understand as well, why LV makes a failed block work (but not perfectly).

This happens almost always like this.

Don't apply what many recommend
at all! It can make things worse!

When the solenoid is stuck, it grinds on the PET body. Losening it with force grinds more!

Sometimes this has brougth the exact adjustment into disorder!

That you can study further here:
https://www.pentaxforums.com/forums/151-pentax-k-30-k-50/388728-why-you-shou...t-replace.html

[swanlefitte]

the moment you switch to LV the aperture closes to the maximum of the lens while it should be f5,6! So metering is not exact but the photo turns out better, i.e. not underexposed.

So it meters for f/22 or smallest opening. How does it focus with so little light? Or doesn't it?

[photogem]

So it meters for f/22 or smallest opening. How does it focus with so little light? Or doesn't it?

AF sensors are under the mirror!

The solenoid actuates twice in LV.
First to open the aperture to f4,0 (parallel mirror up for LV direct onto the LCD screen)
But with stuck solenoid aperture remains closed at max. f of the chosen lens
When one then pressed the release button there are more mA's available and the solenoid can draw more energy and actuates all the sudden
but not forever. Usually after a few weeks LW stops working as well.
One can study this perfectly well on a K30/50/500, they work well open with inserted battery, not so K-S1/2/70

K7/5/3/KP/K1 meter differently in LV-mode, aperture is not fixed to f5.6 but changes depending on light conditions and which mode (Av/Tv/Tav etc) is chosen.

[swanlefitte]

AF sensors are under the mirror!

The rest of what you said seems to make sense and interesting how the cameras vary.

But i was under the impression.
The Difference Between a DSLR's Viewfinder Autofocus and Live View Autofocus | Fstoppers
contrast detection analyzes an image from the sensor itself,

Is that not the case? With stuck solenoid liveview is stuck at f/smallest opening
But you say it doesn't focus off the sensor (?) But still at f/small

[photogem]

If you use LV and you set your camera on M-Mode and select different aperture values except A on the lens,
do you see any difference on the LCD when you change aperture?
I hardly use LV but 99% OVF

by the way:
My Tamron 70-200/2,8 and my SMC Pentax F135/2,8 both open to f4,0 in LV.
But my Pentax 28-105 changes: 28mm = f4 to wide open at 105mm.

[krgroothuis]

I strongly recommend the repair NOT done via the official channels. Because they only have the green solenoids of the newer supplier. They give the problems. I once bought a white solenoid via Ebay. They come from old K_X or older Pentax camera 's. I paid some 40 $.

[swanlefitte]

If you use LV and you set your camera on M-Mode and select different aperture values except A on the lens,
do you see any difference on the LCD when you change aperture?
I hardly use LV but 99% OVF

just tried with the 77mm, liveview is fully open unless you put it on "a", then it stops down. If you turn it to "a" while in liveview it turns liveview off.

[photogem]

That was not the question.
Of course the aperture is fully open because the camera meters like that.
My question was: Do you see always the same object/scene/light on the LCD screen no matter which aperture you chose on the lens?

[swanlefitte]

Yes. Just realized i hadn't checked shutter or iso. No change for any.
What was weird was when i first turned the camera on and went to live view, changing the aperture was stopping down. I couldn't repeat this.

I did answer by saying on 'a' it stops down as we know it is always on f/4. Thus i was referring to the light seen in liveview stopping down meaning it changes. My thinking doesn't always communicate easily.

[Smoke665]

I hate to be the bearer of bad news, but just about any repair on the K30 quickly exceeds the value of the body. When my meticulously cared for K30 developed problems, by the time I looked at the cost of repair and shipping, it wasn't that much more to just upgrade. Why I still have the old K30 in a box, in a drawer, is beyond me😞