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jongonfishin
1st October 2012, 08:42 PM
Hi, Just come back from a camera club meet where the project was "Light Trails. We where all set up in the darkened room and I had my E-600 set at 20sec F16 exposure, manual focus and set to Raw. Got some good shots but the problem was the amount of time taken to write to the card. Is it a common fault with the 600 or could it be the card which is a PNY Optima C/F 8gb. Lenses used were, 14-42 kit lens and Yashica 50mm 1.4 ml with adapter.Thanks in advance for any help.
regards
Dave

Bikie John
1st October 2012, 09:52 PM
It could be one of the noise reduction options. I can't remember what it is called offhand, but the idea is that when you have taken a long exposure it automagically takes a "dark frame" of the same duration. That will give it a picture of 20 seconds' worth of pure sensor noise, which it will subtract from the original exposure. All very well, except that it keeps the camera busy for 20 seconds after you think you have finished the shot.

Hope this helps ... John

jongonfishin
2nd October 2012, 12:18 PM
Hi John and thanks for the quick reply. I think I understand what you are saying. As I understand it (now I've looked at the manual which I should have done in the first place) the length of time taken is normal at slow shutter speed with noise reduction at ON or Auto? So I assume a better c/f card would make no difference. Sorry if the questions sound less than intelligent but I still live in a world when 35mm film cameras were king and noise was what came with heavy lorries and two stroke motorbikes.
Regards Dave

theMusicMan
2nd October 2012, 01:32 PM
Dave

Jon is right - the E600 will have 'dark noise subtraction' on by default for exposures I think that are over 5 seconds. This is not a bad thing by the way, as dark noise subtraction is a way of eliminating possibly significant amounts of noise from long exposure images. I always use it for my long exposure shots. It's nothing to do with the camera writing to the CF card, and it's not a fault either :)

'NR' being turned on is something different; this is a camera function that when enabled, removes noise from images taken at all lengths of exposure and usually does a good job of removing noise as a result of high ISO.

Hope that helps.

Chevvyf1
2nd October 2012, 01:32 PM
It could be one of the noise reduction options. I can't remember what it is called offhand, but the idea is that when you have taken a long exposure it automagically takes a "dark frame" of the same duration. That will give it a picture of 20 seconds' worth of pure sensor noise, which it will subtract from the original exposure. All very well, except that it keeps the camera busy for 20 seconds after you think you have finished the shot.

Hope this helps ... John

Interesting to note this :) I wonder if the E-5 is the same ? Do you know John ?

theMusicMan
2nd October 2012, 01:34 PM
Interesting to note this :) I wonder if the E-5 is the same ? Do you know John ?

Yes Chevvy, it is the same on the E5... as on most E-Series models too.

As I mentioned in the post above - dark frame noise subtraction is a good thing and helps reduce noice. This will improve the quality of your long exposure shots.

Bikie John
2nd October 2012, 03:37 PM
No worries Dave, the question is not unintelligent at all and I can quite understand why you were baffled.

As MusicMan John says, all the E-series cameras are similar on this. The problem is that long exposure images start getting odd bits of light in them from electronic noise on the sensor, and Oly offer us two ways of dealing with it, which (for the E-5 at least) it calls Noise Reduction and Noise Filter. Noise Filter takes the standard image and applies the same sort of noise reduction alogorithms that you find in Photoshop and other software, so it may well mask the noise but at the cost of reducing image sharpness. The Noise Reduction option tells it to take a second dark frame and subtract it from the first. This is a much better way to deal with noise but comes at the cost of doubling the effective exposure time.

Normally I would expect to leave it turned on and put up with the delay. An instance where you might want to turn it off is astrophotography. Astrophotos are particularly prone to noise and they tend to have long exposures and are largely dark so the noise shows up - and is difficult to deal with in post-processing because it will tend to swallow the stars as well as the noise! Astro togs get round the problem by stacking several exposures together to help overcome things like atmospheric shimmering. But if they used the in-camera noise reduction it would double the length of every exposure so it is common practice to turn it off and shoot a few dark frames manually and let the stacking software sort it all out.

Ciao ... John

Chevvyf1
2nd October 2012, 03:54 PM
Yes Chevvy, it is the same on the E5... as on most E-Series models too.

As I mentioned in the post above - dark frame noise subtraction is a good thing and helps reduce noice. This will improve the quality of your long exposure shots.

John I shall try it - not done ANY :eek:

Ulfric M Douglas
2nd October 2012, 05:32 PM
I think I understand what you are saying.
Let's hope so.
It's not writing to the card, it is simply doing another exposure with the same settings but ... black.
A clever thing indeed!

jongonfishin
2nd October 2012, 08:11 PM
Hi John and John, light has now dawned in this old frazzled brain. I was surrounded by Canon,Nikon and Sony users at the club project last night but not one of the "Experts" was able to explain the flashing light on their cameras apart from the odd one or two who commented "Its writing to the card", hence my original question lol. Thanks for your help and I now know where to come for helpful and quick answers. Thanks again.
Regards to all
Dave