[johnnybodybags]

if you guys are anything like me, you've been having a hard time figuring out how to set the shutter speed using the previous posted trick (seen here). after messing around with the camera today, i may have stumbled upon a different method where you can actually LOCK shutter speed IN STILL MODE.

step 1: use a manual lens (will NOT work with kit lens).
step 2: go to "P" (Program Mode) on the dial (the camera will say it's in Av mode.)
step 3: set ISO to 100 *. achieve desired shutter speed by pointing at (or away from) light source.
step 4: press AF/AE-L. the asterisk will appear on the LCD and the settings will be locked.
step 5: go to VIDEO on the dial. the asterisk will still be locked. the shutter speed locked in P mode will be retained.

* make sure it's in ISO100 or the shutter speed will be divided appropriately. (ie: if you're in ISO400 with a 1/200 shutter selected, the ISO will revert to 100 and shutter speed to 1/50 once in video mode.)

notes: it seems there's a limit to how low the shutter speed can go. i don't see much difference between 1/25 and 1/10. maybe there's only a few different speeds that can be selected?

test this out. see if it's right. maybe there's something i missed?

[Coby]

You da MAN!!!!!! Definitely seems to be working here!!!

One thing - my guess is that you can't force the shutter below 1/24 (or 1/25?) in video mode. But this is a great way to avoid excessively high shutter speeds ... I'll update the link you referred to.

[Coby]

OK I've been experimenting with a Pentax-A 50mm f1.4. In "A" mode, the trick won't work. If you move the aperture ring onto manual f-stops the trick works, but the lens is permanently at f1.4 (i.e. it doesnt stop down when you switch to Video mode).

BUT ... if you twist the lens mount slightly to deregister the contacts between body and lens you gain mechinical control of the iris and not only does the trick work but it also provides two very good things: 1) you can adjust the iris to obtain the desired shutter speed, and 2) you can continue to adjust exposure up or down after locking the shutter!

Sadly, my newer zooms with no mechanical aperture ring aren't able to be used in this way

[johnnybodybags]

i wonder if this method can be used to lock in the ISO instead? i mean, if the lowest the shutter speed goes (by default) is 1/24 (or something around that) than, if we're willing to accept that speed, can we instead push the ISO to 6400 and lock it in?

or is the k-x stuck at ISO 100 in video (as previously thought)?

or am i making no sense at all now? will go test.

[NunoBarbosa]

You're THE MAN!

I'm anxious to get home and try it!!!

[karl79]

Just tried it and it works, so I have to repeat:

YOU'RE THE MAN!!

But there is something I'm not quite sure about.
I made a test, in P mode I chose ISO 100 and a shutter of 1/25. I think that's the slowest shutter possible for video, at least that would be logic.

I lock it and switch to video mode, the exposure stays as locked, just as johnnybodybags pointed out.

So what exactely happens if I now tweak the AV +/- settings?


I made a test while the P settings being locked in video mode, I hit AV button and turned it to -3 and the exposure got darker. I turned it to +3 and it got brighter.


How can it get darker if settings were already at ISO 100 and shutter 1/25??
EDIT: I wrote a wrong conclusion here before, question is: how can it get darker if shutter is not affected by AV +/- ? Is it affected then?


And if it get's brighter with AV +3, it must be due to a higher ISO if 1/25 really is the slowest shutter speed in video mode, right?


(I was using a full manual lens btw, no auto settings possible)

I'm just confused about what tweaking AV +/- really is affecting in camera...

[Coby]

Kark, my guess is it gets brighter by adding gain - good find! Will need some testing to confirm....

[karl79]

or is the k-x stuck at ISO 100 in video (as previously thought)?

or am i making no sense at all now? will go test.

You do make sense, I'm quite sure the ISO is not locked to ISO 100 regardless of what might have been said.
I'm afraid it'll take some more experimenting before knowing anything for sure, but you brought it a whole step further with your finding already!

[karl79]

Kark, my guess is it gets brighter by adding gain

Hey Coby, so what's the difference between increasing ISO and adding gain (except that "gain" sounds a LOT worse )?
I think I'm mixing these two things a bit?

[BrianStanding]

Why, oh why, cannot Pentax (or any other DSLR manufacturer, it seems) simply put a "Full Manual" mode on this camera? Where you manually set ISO, aperture, shutter and focus without having to jump through all these silly hoops?

Pentax sold millions of fully-manual K1000s back in the 35mm day, even against competition that was pushing auto everything. I can't imagine it would cost Pentax a dime to have a fully manual program in the firmware of their DSLR line. Why are they so reluctant to offer it as an option?

Or are there really so few of us manual photography/video purists that it isn't worth even that tiny bit of bother?

[brandoniscool]

works fine

adjusting AV +/- settings seems to affect shutter speed only. unless you the shutter speed limit, then up goes ISO

AND

in video mode after locking the exposure, you can use 'optical preview' to preview your adjusted aperture to maintain correct exposure

i think

[p0opstlnksal0t]

Nice im glad ive been buying up cheap manual lenses lately!

[centino67]

in video mode after locking the exposure, you can use 'optical preview' to preview your adjusted aperture to maintain correct exposure

i think

This is quite true. I set the green button to check 'optical preview'. I find it very useful when shooting video to ensure I have the exposure where I want it before I begin recording.

[jogiba]

Step 5: go to VIDEO on the dial. the asterisk will still be locked. the shutter speed locked in P mode will be retained.

I tried my K-7 with 85mm F1.4 Rokinon and the AE-L asterisk is gone when switched to movie mode.

[Coby]

Hmmm... I was wonderring about the K-7.

Jogiba - did you see 'Av' at step 2? If not try again, with your lens slightly twisted in the mount to decouple the connectors (if there are connectors on that lens).

Karl79 - adding gain and increasing ISO both mean increasing the camera's sensitivity to low light = the same thing, in this context!