Originally posted by Larrymc Hi Folks,
A couple of days ago I took a bit of time to take some late afternoon photos of passing towboats along the Mississippi River with my K-3. The photos came out very grainy and I'm totally puzzled as to what caused the grain. I've posted a photo and I hope someone has a few suggestions. I've looked at the EXIF file and the Maker's Notes file and can't see anything that stands out. The lens is a Sigma 885109 18-200 f3.5-6.3 DC OS HSM which normally takes some pretty good photos teamed with my K-3. The focus on this particular photo isn't tack sharp but I'm not concerned about that due to the windy conditions on the observation platform I was shooting from and the fact that I took the shot at 1/100and 200 mm. The only change I've made lately to the in camera settings was a change from Bright to vibrant in the photo parameter adjustment and a sharpness change to fine sharpness On, extra fine from OFF.
Thanks
Noise depend mostly of light level. If there less light that hit the sensor you get more noise. If these less constrast in the scene, it is more visible too.
Here you get low constrast for several reasons:
- the apperture f/14 is likely not the best of your lense... The lense is more likely to washout details at f/14 than say f/8. This is called diffraction and reduce the contrast and level of details your lense will provide.
- the lighting condition force you to get low constrast in some areas (like the forest in background).
Also you used iso400
You used iso 400 on a with very low constrast in some area (like the trees) so that's to be expected.
Your parameter where f/14, iso 400, 1/100s... I really think that you would have gotten better results from f/8 or f/7.1 iso100.
Also post processing can increase noise if you pushed shadows, increased constrast/micro constrast on the picture, all of this basically stretch the photo and increase resulting noise. But post processing can also allow to reduced noise. If you enabled prime noise reduction on DxO prime starting from the RAW, the noise would have entirely disapeared in your situation.