FZ50 in S mode

My exposure in A mode was good. My exposure using S mode told a different story. In the S mode as I increased the shutter speed using the thumb wheel the pictures got progressivly darker until finally at 1/2000 the camera selected F9.3 and the picture was black. My old 35mm intuition told me that the higher the shutter speed the larger the lens opening and that would be numerically smaller F stops. Why is my Panny doing just the opposite. What part of digital photography don't I understand and how do I get the Panny to behave? Have I inadverently entered a wrong setting?

The FZ50 restricts shorter shutter speeds above 1/1000 sec to higher values for f-stops. If you adjust a shutter speed of 1/ 2000 sec you have to use a f-stop of F8-F11. I also really don't understand the reason for this, but if there were a mechanical shutter inside the camera, its possibly not quick enough to shut bigger openings of the lense.

Is there a member of this forum, who can explain this ?

regards

Olaf

My guess is, you're right. It's a leaf-style shutter, not a moving curtain as in an SLR, so if the aperature is too wide you would likely see significant vignetting at high shutter speeds as the central area is open longer than the edges.

Sterling

Somehow the excellent answer to this question ended up in my BIF thread

http://forums.dpreview.com/forums/read.asp?forum=1033&message=24960916
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SterlingBjorndahl said:

My guess is, you're right. It's a leaf-style shutter, not a moving
curtain as in an SLR, so if the aperature is too wide you would
likely see significant vignetting at high shutter speeds as the
central area is open longer than the edges.

Click to expand...

Yep I'm pretty sure that's the case, the shutter isn't fast enough to open and close at 1/2000th of a second when not a narrow apperature...

I also find this annoying, something Panny could improve I hope!

--
Cloverdale, B.C., Canada
Panasonic Lumix FZ50, Pentax *ist D
http://joesiv.smugmug.com

one more observation on this: I had a look at the Leica Vlux-1 manual, and apparently that camera has the same limitation.

While I was very annoyed when finding out about this limitation it is good to have now at least a solid technical explanation for its reason. Thanks!

From old film cameras with that type of shutter I remember also shutter speed down to e.g. only 1/500.

However: if the reason for not combining fast shutter speeds with open apertures is, that the sensor in the middle of the picture would be 'overexposed' compared to the edge of the picture: couldn't this be overcome by some in-camera-PP?

While we continue guessing about the reason for the limitation, what are the workarounds:

S Mode: only go up to 1/1000 sec (brings me personally back to my AE-1 Program behaviour)

A Mode: be very careful when using open apertures in bright daylight. Very careful! If light situation is changing quickly, and you don't always have time to check exposure before releasing the shutter, it is better to go to P Mode to ensure proper exposure, but you may be loosing on DOF control (as few as there is with FZ50)

--> I am not happy with this workaround at all, so if anybody has a good idea it would be highly appreciated!

P Mode: do not do program shifts towards open apertures under bright daylight conditions (you would have same behaviour as in A Mode then...)

Jordan.

Schijo said:

A Mode: be very careful when using open apertures in bright daylight.
Very careful! If light situation is changing quickly, and you don't
always have time to check exposure before releasing the shutter, it
is better to go to P Mode to ensure proper exposure, but you may be
loosing on DOF control (as few as there is with FZ50)

Click to expand...

Just out of curiosity, what's the worry about using A mode on bright days? I almost always am in A mode.

My mentality is that if I want the fastest shutter speeds possible, opening up the aperature will get me the fastest aperature speeds possible. Perhaps if it's too bright it will over expose? I've never really had this problem at ISO100 which I primarily shoot at. Maybe it doesn't get as bright up here north of the 49
--
Cloverdale, B.C., Canada
Panasonic Lumix FZ50, Pentax *ist D
http://joesiv.smugmug.com

I didn't think this type of camera had a mechanical shutter, I thought they used an electronic shutter as the sensor is constantly exposed.

John

My usecase is just like yours: most open aperture, shallow DOF, camera adjusts the shutter speed, nothing to worry about. That was my usecase with my film SLR (up to 1/4000 sec though).

Now I got my FZ50 just before my summer vacation and wanted to use just this way, with the result, that with f/2.8 used outdoors on a normal sunny day (in southern Europe) with ISO100 and 1/1000 sec pictures would have continuously been overexposed. And my expectation really was that I would able to use 1/2000 if it is advertized like this in the specs.

So I had to carefully adjust/close the aperture in A mode, or use P Mode.

Anyway: what is the use of implementing 1/2000 if it just works together with f/11? I do not see any usecase for that whatsoever, and putting 1/2000 into the spec without being able to use it with open aperture to me is very much misleading the consumer. It would be more fair not to quote the 1/2000 sec in the spec at all.

Interesting. Why would we then have the limitation that
Does anybody know details on the shutter implementation in FZ50?

JohnMcL7 said:

I didn't think this type of camera had a mechanical shutter, I
thought they used an electronic shutter as the sensor is constantly
exposed.

Click to expand...

Yeah there is a mechanical shutter, if you have the camera or something similar, just half press, you'll hear the aperature shrink, then fully press, you'll hear the shutter fully shut and open. Alternatively if you look down the lens you can see it do the above as well.

If it was electronic it could potentially do far far faster than 1/1000th, which would be neat

Schijo said:

Interesting. Why would we then have the limitation that
shutter speeds can only be combined with f/5.6 or closer?
Does anybody know details on the shutter implementation in FZ50?

Click to expand...

I guess you could do f/5 or something and get 1/1400th or something.

There really isn't much need for over 1/1000 in every day shots I find, even sports shots, though yes if you want maximum blurred backgrounds f/2.8 is the way to go.

I find that f/5ish is great since it offers the sharpest results, so I typically stay around there.

--
Cloverdale, B.C., Canada
Panasonic Lumix FZ50, Pentax *ist D
http://joesiv.smugmug.com
--
Cloverdale, B.C., Canada
Panasonic Lumix FZ50, Pentax *ist D
http://joesiv.smugmug.com