Anyone know what causes these lines...


Karl

Link Posted 18/03/2009 - 23:32
I took the 2 shots after each other with the same camera settings. K100D, Manual SMC M 40-80 lense, ISO 1600

The first shot is ok but the second one seems to have horizontal lines running across it about 2/3rds of the way down. Anyone know what they are or what causes them?






paullucas

Link Posted 19/03/2009 - 00:35
They are teeth

Seriously that's the only thing that I see that's different, I can't see any horizontal lines apart from the pooches snappers.

Could you highlight the lines?
Unless they are the lines on the left of the dogs face, only thing it could be is dirt on the sensor...Dunno!

Paul

amoringello

Link Posted 19/03/2009 - 00:41
Looks like typical sensor noise from low light to me.

pentaxian450

Link Posted 19/03/2009 - 00:49
I can see faint lines on the right hand side of the picture between the mouth and the nose of the dog, but I don't have the slightest idea as to what might be the cause. As far as I know, they might also be there on the first picture, but since that same area is brighter, you may not be able to see them. I don't have a 6meg Pentax, so as far as I know, it might be a normal behavior of the sensor under certain lighting/contrast situation. Unfortunately, that's all the help I can give you.
Yves (another one of those crazy Canucks)

sanderscapes

Link Posted 19/03/2009 - 06:21
Sorry mate cant see anything but i do wear glasses

ttk

Link Posted 19/03/2009 - 09:54
amoringello wrote:
Looks like typical sensor noise from low light to me.

Low light and high iso, I agree typical sensor noise.
Tel,

Karl

Link Posted 19/03/2009 - 16:51
Cheers for replies. If they are sensor noise, I am considering getting a K20D when funds permit. Would this camera still display sensor noise when using high iso/low light?

sanderscapes

Link Posted 19/03/2009 - 16:56
I use a k10 most cameras would display noise at a high iso with low light levels some more than others
Last Edited by sanderscapes on 19/03/2009 - 16:56

paullucas

Link Posted 19/03/2009 - 17:05
Karl wrote:
Cheers for replies. If they are sensor noise, I am considering getting a K20D when funds permit. Would this camera still display sensor noise when using high iso/low light?

All cameras suffer from noise if they are of a high ISO and low light, you will still get it even if you bought a K20D. Another problem is that the pictures are very out of focus so it's really hard to see any lines, my guess is that it is only noise.

Reduce the ISO and use bounced flash instead.

Going back to good old film, I remember using 3200iso film in black and white, I used it as I loved the grain in my pictures.

Paul

Edited as my spelling is awful, back to school me thinks
Last Edited by paullucas on 19/03/2009 - 17:23

scottthehat

Link Posted 19/03/2009 - 17:21
i see it bottom left hand side, hard to say but looks like noise,

Karl

Link Posted 19/03/2009 - 18:38
In order to add the film grain effect is it better to use a photoshop plug in? as opposed to setting a high ISO on the camera?

Also, how much can you push the ISO in a digital SLR before you start to get the noise?

sanderscapes

Link Posted 19/03/2009 - 18:53
About iso640 and upwards but all dslr's will be different.I try to keep the iso to a minimum whatever type of photography i'm doing

iceblinker

Link Posted 19/03/2009 - 21:39
You get noise with all digital cameras at all ISO settings. It's just a question of how much.

The (slight) problem with the picture above is banding. You don't always or ever get any of that with all cameras, just sometimes with some due to a fault or quirk.

Banding effects can be removed from RAW images by Silkypix Developer Studio via Geometric NR. I don't know if Photoshop has anything similar.
~Pete

RR

Link Posted 19/03/2009 - 22:34
It has nothing to do with noise. It's because this dog is called "Belle" but you used "Spot" metering. Therin lies your problem, you need to find a dog called spot...


Just kidding, I concur, noise !

I try to shoot at the lowest possible iso to avoid noise, only raising it when other avenues have been exhausted.

The K20d has a cmos sensor which seem to produce less noise than ccd sensors, but higher resolution sensors lead to higher noise too.
Also, Pentax take it easy on in-camera noise reduction compared to their rivals. This leads to a noisier image but retains alot more detail. You can then tailor noise reduction to the images using software during post processing.
More work but better results as you choose the balance between detail & noise, and lets face it, a home computer with a few gb of ram & more complex algorythmic software is going to do a better overall job than a dslr ever will.

There are plenty of noise reduction programs around & I can't confess to trialling many, but I've found Nik Software's Dfine 2.0 to be very easy with great results.
It's always best to reduce noise at the first step of PP as any contrast, saturation, sharpening adjustments etc can accentuate the noise & make it more difficult to reduce successfully later on.

And to answer your question about grain, I would add it with software if required as grain (even fake grain) is more pleasing to the eye than digital noise.
My Flickr

iceblinker

Link Posted 20/03/2009 - 00:49
It's not about noise per se, but specifically banding in the noise, which is not normal, no matter how high the ISO. It's a fault with the camera, albeit a very very slight one in this case.
~Pete
Add a Comment
You must be registered or logged-in to comment.