Why do my photos look like this?

Senor Hound · Jun 22, 2008

Here is a crop of one of my photos at 100% My question is why it looks so pixely? Btw I think it was shot at ISO 100 and medium sharpness.

I wouldn't think I should see that much variation on a solid background. It looks horrible. But what I don't understand is why my image quality IMPROVES when I reduce the size. I mean, my camera should be registering accurate data for each pixel, so it should be the same image quality, no?

Anyway, Help would be appreciated. I just want to know if this splotchiness (new word) is to be expected or if its something I can fix (and if so, how).

Josh66 · Jun 22, 2008

It's normal to see that at 100%.

Even at 100%, it looks fine if you stand far enough away. It's like holding a poster 6 inches from your face - it ain't gonna be pretty.

Jedo_03 · Jun 22, 2008

Hi Mr Hound
Dunno what "splotchiness" means but you have a degree of underexposure here...
Looking at the histogram - pictured here:
You can see that all of your pixels (data) are piled up to the left...
Granted there are no whites/lights in the image, even so your ideal would be a nice mountain in the middle... dial out -1.0 to -1.7 EV and retake the shot... (if you don't understand why - just ask...)
Lotsa noise there too... could be an artefact of the underexposure, but definately an increase in S to N ratio...
I dunno about the shadow gradient bottom right - could be that the shadow wasn't so noticeable through the viewfinder - and now excacerbated by the approx 1.5 stop UE...
Jedo

ANDS! · Jun 22, 2008

Under/over-exposure is irrelevant here. All photographs like that when viewed at their proper size. I asked myself the same thing when I first viewed my photos full sized.

Pixels are pixels, blocks - remember that. Even though you have a **** load of pixels, at a certain magnification you are going to be able to see "blocks"; the reason is looks "better" resized, is because you are making those "blocks" (and their subsequent blockiness) smaller and less visible. It really is all very natural.

LaFoto · Jun 22, 2008

While I don't know which one's the photo out of which you took this 100% crop, I do find that also my pics show all their "flaws" (as it were) when cropped at 100%. I tested it on two pics that look sharp when viewed as whole, were taken at ISO 100, and with my kit lens. And then I tested it on another photo taken at ISO 400 with the Sigma ... and *gulp* and *gasp*, look how horrible they are thus "magnified"!

"Original"

100% crop

"Original"

100% crop

Above examples taken at ISO 100 with 350D kit lens

Below example taken at ISO 400 with Sigma 70-300mm lens

Original - converted from RAW to -.jpeg only

100% crop

See?
It's normal.

Jedo_03 · Jun 22, 2008

Don't know whether to disagree or not...
Here's the full frame
and the 100% crop of her right eye
can't see any degradation/artefacts/noise/pixelation/blocking...
Bit unsharp - but Kh-Rist, viewed to scale on your monitor, the EYE image would be as big as half a door...!!!
Not a rank and file techo - but doesn't it depend how many pixels you are utilising...
Seems to me that a 6Mp or 10 or 12Mp image contains a helluva lot more pixel info than (say) a 2Mp... a 2Mp image doesn't have the physical dimensions of a 10Mp image because it has a lesser number of pixels - therefore the quality of a(100%) 800x600p crop of a 10Mp image is going to be better quality than a (100%) 800x600p crop of a 2Mp image because the 10Mp image has a greater DENSITY of pixels and so the overall quality of the image is increased... ie more info per square mm on the sensor...
Ah well - the experts know best...
So...
I'll just shaddup and sip me glass of home-made muscat and banana wine.
Cheers
Jedo

AndrewG · Jun 22, 2008

I'm not sure that I see the point in blowing up an image-or a portion of it-so you can examine 'flaws'. If the image, as you want it to be viewed, and at the size you want it viewed, is acceptable then that should be sufficient, no? No one is going to examine your pictures with a loupe.

manaheim · Jun 22, 2008

I've been doing some of this lately too... it's a bad obsession with me and I get super annoyed knowing that there is noise or whatever other mess when you zoom in to 100%. I'm glad someone else came forward and posted their madness because I thought I was alone.

For me this all started when I started hunting for dust on my sensor, which I've had a lot of since I have been switching lenses more. (we HATEs the dust on the sensor. HAAAAAAAAAAAAATES IT!!)

I have noticed that it isn't on ALL of my pictures, and have been seeing that the more properly exposed the subject, the better it is... if there are other aspects of the image that are less properly exposed, they have more of this noise/grain/whatever. That suggests to me that exposure does have a lot to do with this.

As to why... I'm always concerned that little details will affect the whole in some tangible but unidentifiable way. For example, if you run through your house and clean nothing but the tops of all the baseboards/floor mouldings... the house will look better and cleaner than it did, but if you asked someone no one could tell you why that is so.

I should probably shut up. I'm probably dragging Andrew and a few others into my madhouse with me. :guilty:

Wanna drive yourself truly buggy? Take a picture of a clear blue sky and zoom in and see that there are darker dots! AAAAA.

Iron Flatline · Jun 22, 2008

Exposure DOES matter. If it is underexposed, it's going to show noise in the darker solid areas.

But at 100% you're invariably coming up against the limits of digital, because that is ultimately what it is: a clever pixel array, not a transparency like film.

Ultimately, looking at it on a monitor that is limited in the colors and dots-per-inches it can produce is also a limiting factor. The final test is what the print looks like.

ANDS! · Jun 22, 2008

In THIS situation and as it relates to his question, whether or not a photograph is over/underexposed is not what matters. His is a question of pixelization, which is going to show up on all of his photographs. Saying that its an "exposure issue" is going to have him (and perhaps others who view this thread) thinking that EVERY photo they have is exposed badly because they can see the pixels.

Don't know whether to disagree or not...

There is no disagreement. Its what the posters above you just said.

manaheim · Jun 22, 2008

^^^

mmm... he may have said pixely, but I really think he's referring to the color noise in the original shot. Senor, are you referring to the fact that your image is made up of pixels, or the fact that it looks like you see funky color variations on individual dots?

God, you know... more and more I'm thinking I should trade in my D300 on a nice Canon AE1. lol

Senor Hound · Jun 22, 2008

manaheim said:
^^^

mmm... he may have said pixely, but I really think he's referring to the color noise in the original shot. Senor, are you referring to the fact that your image is made up of pixels, or the fact that it looks like you see funky color variations on individual dots?

God, you know... more and more I'm thinking I should trade in my D300 on a nice Canon AE1. lol

I guess it would be color noise. I just don't understand how one pixel can register a certain color and the pixel right next to it seemingly register a different color when the background is the same. The background doesn't look smooth and uniform, it looks like there's lots of variations in it. Some of the pixels look redder than others and whatnot. You know? And even though it is low-key, its at ISO 100! I wouldn't think this would cause issues at such a slow speed (but its there regardless of ISO).

Joves · Jun 22, 2008

Iron Flatline said:
Exposure DOES matter. If it is underexposed, it's going to show noise in the darker solid areas.

But at 100% you're invariably coming up against the limits of digital, because that is ultimately what it is: a clever pixel array, not a transparency like film.

Ultimately, looking at it on a monitor that is limited in the colors and dots-per-inches it can produce is also a limiting factor. The final test is what the print looks like.

I totally agree. The under exposure will magnify any noise and, then cropping it magnifies it even more.

ANDS! · Jun 22, 2008

Senor Hound said:
I guess it would be color noise. I just don't understand how one pixel can register a certain color and the pixel right next to it seemingly register a different color when the background is the same. The background doesn't look smooth and uniform, it looks like there's lots of variations in it. Some of the pixels look redder than others and whatnot. You know? And even though it is low-key, its at ISO 100! I wouldn't think this would cause issues at such a slow speed (but its there regardless of ISO).

Unless you had the EXACT SAME amount of light falling on each of the individual "pixels" of the image, then yes its not going to be "uniform".

manaheim · Jun 22, 2008

I went and googled a bit to refresh my understanding of this problem.

http://www.photoxels.com/tutorial_noise.html

^^ has a couple loopy comments, but seems overall pretty accurate and complete.