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02-15-2007, 12:34 PM   #16
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QuoteOriginally posted by Alvin Quote
During a long exposure, stray light can enter the camera through the viewfinder. This will throw off elements in the capture
Fascinating - I didn't know that.

How long is "long"?

Will

02-15-2007, 03:01 PM   #17
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QuoteOriginally posted by WMBP Quote
Fascinating - I didn't know that.

How long is "long"?

Will
Hi Will, unfortunately there is no real answer to that as it depends on what kind of ambient light is around you. Out in the country with little outside ambient light, probably a long time. In the city I've had problems with 5 second exposures. Last 9/11 I was trying to get a nice pic of the twin searchlights they light each year in commemoration. If there is any moisture in the air they can be clearly seen from my front porch. I didn't know about the rear view finder condition at the time and I got super grainy barely perceiveable shots. I had a range of exposure times from 5 sec to 30 sec and all were bad.

NaCl(next year I'll be prepared)H2O
02-15-2007, 03:25 PM   #18
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QuoteOriginally posted by NaClH2O Quote
Hi Will, unfortunately there is no real answer to that as it depends on what kind of ambient light is around you. Out in the country with little outside ambient light, probably a long time. In the city I've had problems with 5 second exposures.
Interesting. Never heard of this. I have not yet taken a 5 second exposure. Is this a problem that only Pentax cameras have? In other words, is it, shall we say, a flaw in the design of these cameras? Or does this occur on all digital SLRs? I'm not quite familiar enough with the mechanics of what happens when the shutter it clicked and the mirror moves out of the way to expose the sensor. I am guessing it's got something to do with that, right?

Will
02-15-2007, 03:43 PM   #19
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QuoteOriginally posted by WMBP Quote
Interesting. Never heard of this. I have not yet taken a 5 second exposure. Is this a problem that only Pentax cameras have? In other words, is it, shall we say, a flaw in the design of these cameras? Or does this occur on all digital SLRs? I'm not quite familiar enough with the mechanics of what happens when the shutter it clicked and the mirror moves out of the way to expose the sensor. I am guessing it's got something to do with that, right?

Will
A lot of SLR's are known for this, not just Pentax. Somehow some light can still enter the viewfinder to get reflected off the mirror into the camera and onto the sensor. To minimize that possibility, there was a viewfinder cap that should have been supplied in your box with the camera.

02-15-2007, 03:55 PM   #20
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QuoteOriginally posted by Alvin Quote
A lot of SLR's are known for this, not just Pentax. Somehow some light can still enter the viewfinder to get reflected off the mirror into the camera and onto the sensor. To minimize that possibility, there was a viewfinder cap that should have been supplied in your box with the camera.
Well, so THAT's what that thingy is for! Thanks for the tip, Alvin.

Will
02-15-2007, 05:16 PM   #21
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Try this: In a dim room with a window to the bright outdoors, remove lens, set camera to bulb mode, point the thing out a window, eye to finder, trip shutter, voila--not black! Viewfinder is not light sealed just because mirror is up. Light is sneaky stuff, it can go 'in' from either direction...

And you'll notice, it's not an even 'fogging' that occurs. Edge or edges are brighter, but there may be other 'bright' areas-see that black interior isn't all that perfect.
02-15-2007, 07:37 PM   #22
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Here's a shot from tonight. This was taken at heavy dusk. I'd say it looks pretty much the way I remember it.

Camera: PENTAX K100D
Timestamp: Thu Feb 15 18:58:47 2007
Shutter: 3 s
Aperture: F5.6
ISO speed: 200
Focal length: 50.0 mm
Focal length in 35mm equivalent: 75.0 mm

EXIF data read by Exiv2 0.10

I put the ISO back to auto when I discovered I could narrow the range down to 200-400. Interesting it selected 200.

Also, I backed the apertur back a stop. Lastly, I put the VF cover on after composing the shot.

Here it is at full resolution. It looks better than my earlier pictures.

02-15-2007, 07:41 PM   #23
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Wow! I was surprised you could upload such a big pic! Nice shot! Almost non-existant grain in the photo too

02-15-2007, 07:50 PM   #24
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Thanks. Maybe I should crop it down a little.

I didn't upload it. I'm hosting it myself.

Buidings and lights on the horizon are not only not sharp, it's tough to make some of them out. The building right across the street is wonderfully sharp.

I could feel the building tremble sleightly from traffic so I would imagine that's where the distant blur is coming from.

Also, I'm still not smitten with the sky gradients. It doesn't look as smooth as I'd like. Is there a way to get it smoother?

Perhaps I'll give it another go at wide open aperture (although this was close), ISO 400, and I'll see if I can find a more stable platform on which to perch my tripod.
02-15-2007, 08:11 PM   #25
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Do you use your SR while it is on the tripod? If not, I would in this case and see if it helps.
02-15-2007, 08:42 PM   #26
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Thanks, Alvin. SR was on.
02-15-2007, 08:46 PM   #27
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You're going to shoot me for this, can you try one shot with it off?
02-15-2007, 10:12 PM   #28
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i would try iso 400.. the aperture as wide as it will go to keep the shutter speed up and sr off.. u could also turn the saturation and contrast down in the menue..

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02-16-2007, 12:41 AM   #29
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Here's one with SR off at full wide aperture, max zoom. This is a crop. There are brighter objects in the shot but this is the distant building I was trying to capture.

I also took this same shot with SR on and can't see any difference.

Camera: PENTAX K100D
Timestamp: Fri Feb 16 01:11:49 2007
Shutter: 1/2 s
Aperture: F5.6
ISO speed: 400
Focal length: 55.0 mm
Focal length in 35mm equivalent: 82.0 mm

EXIF data read by Exiv2 0.10

02-16-2007, 12:47 AM   #30
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Here's a scaled down look at the whole shot. Notice how much better the building on the right looks.

I'll also mention that I was running Ev -2.0 on this shot. It was taken at 1:15 am and this is approximately how it looked to my eye.

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