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08-26-2015, 06:18 PM   #1
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K-3 Graininess in Photo.....I need a little help

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

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Last edited by Larrymc; 08-26-2015 at 06:23 PM.
08-26-2015, 06:38 PM   #2
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Were you using a lens hood, because it seems to lack contrast to me? The only thing I notice in the EXIF is that you used spot metering which may have messed up your exposure.
08-26-2015, 07:20 PM   #3
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I used a lens hood and the spot metering was used to get the correct exposure on the white towboat but that could have been part of the problem. When I zoom to say 200% I can see tons of graininess in the background trees. I've never experienced that before.
08-26-2015, 07:29 PM   #4
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QuoteOriginally posted by Larrymc Quote
When I zoom to say 200% I can see tons of graininess in the background trees. I've never experienced that before.
What does it look like at 100% ?

08-26-2015, 07:42 PM   #5
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QuoteOriginally posted by Steve.Ledger Quote
What does it look like at 100% ?
Steve, its very obvious at 100% in the trees in the background and also on the black panels on the boat. Unfortunately I deleted the RAW files after looking at them so just the .jpgs are all I can reference. I think it may be related to the sharpness settings but those should only affect the .jpgs. I've changes the sharpness setting back to what I was previously using. I changed them on the suggestion of a so called "Pro" who uses the K-3.
08-26-2015, 08:16 PM   #6
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When I see the word "grain" I think of: 1) high ISO noise; 2) artifacts from oversharpening. I don't see either problem in the sample above. You said you see the grain when zooming 100% and that you subsequently adjusted your sharpness setting. I hope that resolves the issue but I didn't see any evidence of it.

That shot is a tricky scene. The bright white paint being lit by full sunlight washes out details on those parts of the boat. The trees in the background lack detail and color due to haze; lots of evaporation over the water. Those issues are unrelated to graininess as I know it.
08-26-2015, 08:27 PM   #7
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Highlight/shadow correction setting?
08-26-2015, 08:40 PM   #8
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QuoteOriginally posted by DeadJohn Quote
When I see the word "grain" I think of: 1) high ISO noise; 2) artifacts from oversharpening. I don't see either problem in the sample above. You said you see the grain when zooming 100% and that you subsequently adjusted your sharpness setting. I hope that resolves the issue but I didn't see any evidence of it.

That shot is a tricky scene. The bright white paint being lit by full sunlight washes out details on those parts of the boat. The trees in the background lack detail and color due to haze; lots of evaporation over the water. Those issues are unrelated to graininess as I know it.
Hi DJ, The grain is very obvious in the SOOC photo but probably not in this one here. The pixel resolution is approx. 1/5 the K-3 SOOC and its really obvious in the original. I tend to think and (hope) it was the sharpening that was introduced prior to this photo shoot and now has been corrected. I'll just have to go back out under approximately the same conditions to shoot again. Here is one from June 3 at around the same time of day and it has very little grain taken with the same lens.

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08-26-2015, 09:44 PM   #9
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Happened to me as well on a few shots: two photos taken within 10 minutes time interval, at ISO200, daylight, similar exposure, same lens, same shutter speed, same post processing, no NR: one photo has a lots of grain, the other not.

Last edited by biz-engineer; 10-03-2015 at 11:44 AM.
08-27-2015, 08:11 AM   #10
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QuoteOriginally posted by biz-engineer Quote
Happened to me as well on a few shots: two photos taken within 10 minutes time interval, at ISO200, daylight, similar exposure, same lens, same shutter speed, same post processing, no NR: one photo has a lots of grain, the other not.
I am convinced this is some of my issue, too. I have had photos with this issue and not been able to explain it.
08-27-2015, 10:21 AM   #11
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QuoteOriginally posted by cgchang Quote
Highlight/shadow correction setting?
Hi Chris,

I'll have to check but I'm pretty sure they are set to whatever default the K-3 came with I don't remember changing them.
08-27-2015, 10:37 AM - 1 Like   #12
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Grain tends to indicate low levels of light in the original exposure. For daylight, I'd probably have used 100 ISO and a tripod. The obvious advantages being, more light= less noise, lower ISO means more Dynamic Range. In bright sun you need all the Dynamic range you can get. Your contrast values are going to be as high as 20,000:1 and the camera at even 100 ISO can't cover it. So you have your choice, blasted highlights or grainy low light areas. (Or if you aren't merging your exposure, both.) Your mission on a shot like this is pretty much doomed by the shooting conditions. The issue of K-3 exposures wandering sometimes when taking multiple shots of the same thing is also something I experience on a regular basis. I have no idea what causes it.

Later in the evening or under the canopy in the forest, Dynamic Range is much less, and you can shoot at 400 ISO without serious grain. In general, the higher your ISO, the more noise you will introduce in the shadows, should you choose to bring them up.
08-27-2015, 01:11 PM   #13
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QuoteOriginally posted by normhead Quote
Grain tends to indicate low levels of light in the original exposure. For daylight, I'd probably have used 100 ISO and a tripod. The obvious advantages being, more light= less noise, lower ISO means more Dynamic Range. In bright sun you need all the Dynamic range you can get. Your contrast values are going to be as high as 20,000:1 and the camera at even 100 ISO can't cover it. So you have your choice, blasted highlights or grainy low light areas. (Or if you aren't merging your exposure, both.) Your mission on a shot like this is pretty much doomed by the shooting conditions. The issue of K-3 exposures wandering sometimes when taking multiple shots of the same thing is also something I experience on a regular basis. I have no idea what causes it.

Later in the evening or under the canopy in the forest, Dynamic Range is much less, and you can shoot at 400 ISO without serious grain. In general, the higher your ISO, the more noise you will introduce in the shadows, should you choose to bring them up.
Thanks Norm,

I'll keep that in mind next time I'm on the river bank or anywhere else for that matter. I'm not quite sure why I was at 400 ISO for that shot. Probably my inattention when I first set the camera I was in a different location and in a forested area in shadow so 400 ISO would have been appropriate for those earlier shots, I guess I just didn't change the ISO when I moved closer to the river and out of the wooded area.
08-29-2015, 06:32 AM   #14
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QuoteOriginally posted by Larrymc Quote
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.
08-29-2015, 06:36 AM   #15
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QuoteOriginally posted by biz-engineer Quote
Happened to me as well on a few shots: two photos taken within 10 minutes time interval, at ISO200, daylight, similar exposure, same lens, same shutter speed, same post processing, no NR: one photo has a lots of grain, the other not.
Please note how noise is visible on both picture but much more on the second one.

Also notice how the exif are the same for shutter speed and isos. Still see how different the exposure is between the 2 pictures. It look like the second picture was processed to increase it exposure and constrast quite a bit and that responsible for the more visible noise.

If that's an issue, apply a noise reduction filter.
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