Quote:
Originally Posted by bcoote
Just looked up a Cnet review
http://news.cnet.com/8301-11386_3-57...n-sensor-test/
On their tests the Ev drops from 14 at ISO-100 to Ev 10.5 at ISO-1600
I have the Mk: 11 which is slightly worse than this.
Despite this I will still probably go for 400-800 ISO as I feel I am only looking for a limited portion of the data unlike say galaxies where you have everything from no signal to over-saturated in the one image group.
But I am certainly open to correction on this.
Joe Cali would you mind telling us what ISO setting you recommend for corona images?
Brian Coote |
In my film days, I used ISO 400 pro-color neg film. Wedding photographer film because it had a wider exposure latitude. Since going digital, I always use the lowest ISO - either 80 on my new camera or 100 on my older camera.
Optical systems are f6-f8
Shutter speeds :
Every shutter speed in 1 eV increments from 1/1000-1/60 for diamond ring
Every shutter speed in 1 eV increments from 1/4000 - 4s for corona.
Earth shine - 8s
The corona has an enormous dynamic range - much bigger than a galaxy.
My best composites are stacks of all 14 stops or 15 if you include the Earthshine and I still struggle to control the contrast.
The dynamic ranges in eV determined by DxO labs (I imagine the CNET tests are similar) don't translate directly to usable stops of exposure latitude on a camera. They are purely a mechanism for comparing sensors. Don't for a moment think you can get a practical 14 eV dynamic working range out of an image even if the sensor test indicates a 14eV range. The usable range is still probably only 6-8eV.
Joe