Dead pixels on the long exposure photos

[tommy345]

Hi guys,
I saw really nice shots on the forum using a long exposure time to take pics. I decided to try myself, but unfortunetely on the pictures with 2sec time and more I see a lot of dead pixels. Is it my Inspire problem, or everybody have it? Here example:

 

[britchris1]

Did you download the DJI DNG Cleaner? http://www.dji.com/product/inspire-1/download

 

[Paul K]

Could you let me know what was a ISO reading , and if you had ND filter on?
Looking at the picture ,it looks overexposed,(a part of the sky has no detail) and the dead pixels are actually a noise .
I would use a manual control to shoot the picture , no filter , use histogram (if you are familiar with the histogram , make sure it doesn't pass the right border), underexpose little and than bring it back in post-procesing. If still any noise use a noise reduction software (just lightly).
I have tested the camera ISO and above ISO 1200 you are dealing already with a lots of noise.

 

[tommy345]

Thanks for the reply. I was using manual settings. I wanted to test a long exposure, that's why I had a ND filter on, and I set the ISO to 100. The picture was taken in 4s time.
What about DNG Cleaner? I dont see the instructions how to actually use it?

 

[Paul K]

I never checked DNG Cleaner ,but I thing it would work as a noise reduction software,or a dead pixel remover ( Nikon use to used something like that ,it basically detects repeated dead pixels and the software will erase them).
I would start a night shoot without any filter ,100 ISO would be the best ,but for night ,I would use something like 400 ISO as a compromise to gain shorter exposure ( you will notice a noise if; the ISO is to high; if the exposure is to long or if you underexpose to much. Thus by removing the ND , rise the ISO to 400 you might end up with 1/2 sec exposure. Plus do some bracketing and than review pictures on the computer screen in actual pixels. Use histogram.
Would be good idea to post your results. BTW the picture above ,is lucking sharpness because of a long exposure.

 

[tommy345]

Thanks for a very usefull tips! I will try next time that kind of settings.
As I was next to the water I was hoping to get also a water movement on the shot, that's why I decided to put a filter and use ISO 100, to use as long time as possible. But that day it wasnt wavy enough to see it well, and I lost some sharpness by using too long exposure. Anyway still amazing stability for 4 second shot and some wind by Inspire! I will practice a bit more and post the results! Thanks!

 

[SkyLabs86]

Some great advice on this thread, thanks guys. Any more shots or tips?

 

[Paul K]

This aren't dead pixels ,but digital noise , and it is cost by long exposure. It doesn't have to be poor quality of the sensor ,but combination of sensor and its algorithm. For example the sony sensors are used in Cannon ,Nikon and Sony cameras ,but each company ,develops its own performance behaviour of the sensor,and that differs performance of there cameras.
My D100 Nikon (16 years ago) couldn't produce IR/ long exposure photo without the noise , but today's even consumer cameras could handle this issue without any problems .
That means ,for now you have to depend on DNG cleaner ,and hope the next Inspire camera will handle this just perfect.