type of SD Card


Feb 15, 2013
359
1
18
Singapore
#1
Afternoon!

I have an enquiry on SD Card

Gear = OMD-EM1
Saved = both JPEG & Raw
Resoution = Large & Fine

SD card = Scandisk Extreme 16Gb 45Mb/s
Situation = 10 sec exposure

I realised each time I took time exposure shot, it took a long time for the card ready for next shot.

What I meant was, if I took a 10 sec shot, the camera took about 10 sec to record before I could take a next shot.
If the next shot not a time exposure type say 1 sec or less, close to immediate, the camera was ready to take a next shot.


The enquiries I have

1) Was that due some kind of EM1 setting, I did not set? If it was I hope you can tell me what settings I should look out to cut short the recording time

2) If that was normal, can I presume if I buy a 90Mb/s or faster? Will the same 10 sec time exposure shot saving duration will be halved?

Thank You
EisMann
 

Oct 26, 2009
459
2
18
Red Dot Island
#2
Hi EisMann,

My experience is the same. You need the 90Mb/s or faster to have a faster write time. Technically how much faster I do not have the spec, but faster the transfer rate the better. However check whether your camera supports the fast transfer rate. new camera should have the issue.
 

Octarine

Moderator
Staff member
Jan 3, 2008
12,518
32
48
Pasir Ris
#3
Doesn't sound like an issue with the card. It reminds me on the noise removal function on Canon. The camera takes a second, 'dark' picture to determine image noise, then this noise signal is subtracted from the taken image. Check for any setting about long exposure noise reduction.
 

Last edited:

kandinsky

Moderator
Staff member
Apr 26, 2008
3,014
24
38
#4
1) Was that due some kind of EM1 setting, I did not set? If it was I hope you can tell me what settings I should look out to cut short the recording time
Sounds like it. Commonly referred to as LENR (Long Exposure Noise Reduction). Should be able to switch off, check your manual for how.
 

thoongeng

Senior Member
Jan 26, 2010
1,260
19
38
#6
Agree with the Mods, sounds like your camera is doing long exposure noise reduction, which Olympus calls simply as 'Noise Reduction' (they call noise reduction for high ISOs 'Noise Filter'). Check your camera's Custom Menus, under 'EXP/ISO' > 'Noise Reduct.', by default is it 'Auto', which means any exposure that is 0.5 seconds or longer, it will take another exposure with the same exposure time with the shutter closed to use it to reduce noise generated by hot pixels on the sensor. Nothing to do with speed of your SD card.

I'm using E-PL6, and I turn the 'Noise Reduct.' to off unless exposures are much longer. I don't find significant noise from hot pixels on my camera from exposures 60 seconds or less. You probably can experiment a bit with your camera to see what is the exposure time you need before you need to turn on 'Noise Reduct.'
 

Feb 15, 2013
359
1
18
Singapore
#7
Morning!

Thanks for the replies, everyone.
Will read & switch off the noise reduction.

Last evening finished off with an evening 30 sec exposure shoot. You can guess how long it took the EM1 to be ready the next shot.

EisMann
 

daredevil123

Moderator
Staff member
Oct 25, 2005
21,660
68
48
lil red dot
#9
Morning!

Thanks for the replies, everyone.
Will read & switch off the noise reduction.

Last evening finished off with an evening 30 sec exposure shoot. You can guess how long it took the EM1 to be ready the next shot.

EisMann
mod kanndisky and Octarine both hit the problem spot on. It is obvious you have long exposure noise reduction turned on.

If you have Long Exposure Noise Reduction (some cameras call it Long shutter NR) turned on, and you do a long exposure, your camera will do a dark exposure of the equal amount of time after the actual shot, and then deduct the noise from that dark exposure from your original shot. So if you exposure is 30 seconds, it will do another 30 second dark exposure. If you do a 5 minute exposure, it will do another 5 minute dark exposure.

Nothing to do with your card write speed. Turn off long exposure noise reduction and you will be fine.
 

Last edited:

wonglp

Moderator
Staff member
Jul 20, 2007
6,816
74
48
Bukit Batok
#10
Yes, long exposure noise reduction (LENR) at work. If shooting a couple of shots of a few seconds, hot pixels should not be an issue but once you shoot long like 60sec etc, hot pixels will set in, then you really need to turn on LENR. For night shots, it can be seen easily on screen once you zoomed in. And if you shoot 60sec, means the LENR will take equivalent amount of time. Hope that helps.
 

Top Bottom