Author Topic: Artifacts at full size rejections at iStock (Read 23692 times)

steheap · « **on:** December 20, 2009, 18:00 »

I have had a big increase in rejections due to Artifacts at full size from iStockphoto recently, and, to be honest, I can't see what they are finding as a problem. I have asked Scout for more details, but no response so far, and so I wondered if the experts here could have a look at three samples and point me to the problem. I have loaded the full size JPGs onto my site:

http://www.backyardimage.com/Photography. The three images are in the gallery called Test-Photos.

The photos are from a Canon 5d Mark ii, processed a little and then exported at full quality jpegs.

Any help gratefully received!

Steve

fullvalue · « **Reply #1 on:** December 20, 2009, 18:08 »

I only looked at the first one, berry sticks, but the sky was full of artifacts. Never sharpen the sky.

kaycee · « **Reply #2 on:** December 20, 2009, 18:12 »

I had the same problem also with Canon 5d mark II.
No sharpen only a bit W/B
But after scouts review they got approved.

Gannet77 · « **Reply #3 on:** December 20, 2009, 18:19 »

Sky does seem to have rather more noise than I'd expect - large expanses of blue sky like that are always a bit of a problem. You could try noise reduction, or perhaps a gaussian blur, with a mask for just the sky.

You'd do better to post in the iStock critique forum. If you're lucky, an inspector will come by and give you a better idea of exactly what they see as the problem.

steheap · « **Reply #4 on:** December 20, 2009, 18:23 »

Thanks for the comments - I did check the metadata - these were taken at ISO 500 because I was handholding a 70-200 with extension tubes. I wish they had rejected them for noise - I know how to handle that - the artifacts rejection (which includes a lot of detail about compression artifacts) confused me a lot.

Steve

Eyedesign · « **Reply #5 on:** December 20, 2009, 18:24 »

Quote from: Gannet77 on December 20, 2009, 18:19

Sky does seem to have rather more noise than I'd expect - large expanses of blue sky like that are always a bit of a problem. You could try noise reduction, or perhaps a gaussian blur, with a mask for just the sky.

You'd do better to post in the iStock critique forum. If you're lucky, an inspector will come by and give you a better idea of exactly what they see as the problem.

Beat me to it Gannet, +1 for the iStock critique forum.

borg · « **Reply #6 on:** December 20, 2009, 18:39 »

I think the problem is in too much non-selective sharpening, contrast or clarity , maybe it is all from the camera...
Check your sharpness on your camera...

Opla · « **Reply #7 on:** December 20, 2009, 18:43 »

Only looked at the first one.
Lost of noise, plus a small dustbun near the right edge, 1/3 from the bottom.
Also, there is some strange streak on the left, not sure what that is.

steheap · « **Reply #8 on:** December 20, 2009, 19:14 »

These are all raw files, processed in Lightroom with nothing other than the normal sharpening that Lightroom applies. Thanks for the advice about the iStock forum!

Steve

cathyslife · « **Reply #9 on:** December 21, 2009, 07:44 »

You have to be really careful about sharpening any photo, sharpening adds noise. Also, try always to shoot at ISO 100. I have never been able to get anything approved at ISO400. I know some people have, and I guess it would depend on the photo. Skies are typically noisy as well as dark areas. Those are two places to look for noise (artifacts) right off the bat.

MichaelJay · « **Reply #10 on:** December 21, 2009, 10:28 »

Quote from: cclapper on December 21, 2009, 07:44

You have to be really careful about sharpening any photo, sharpening adds noise. Also, try always to shoot at ISO 100. I have never been able to get anything approved at ISO400. I know some people have, and I guess it would depend on the photo. Skies are typically noisy as well as dark areas. Those are two places to look for noise (artifacts) right off the bat.

No, sorry but wrong: Noise and artifacts are two completely different things. As a matter of fact, areas with large artifacting can be saved by adding some noise, it makes in image look more natural and reduces the harsh squared artifacts in many cases.

Sharpening is one option to create ugly artifacts. But basically they are generated when the digital image is processed, either during the compressing that happens when you save it as JPG (even at largest quality JPG is a compressing file format) or already during taking the picture when you work on the edge of the dynamic range of the camera sensors.

Some degree of noise is totally acceptable if it fits the image and the base image is large enough - at 21 megapixels from the 5DII, I wouldn't consider the noise in the sky a big problem. Question is why is the image shown here so small? Too much cropping?

Anyka · « **Reply #11 on:** December 21, 2009, 10:55 »

I understand noise. But when Istock refuses images for "artifacts", it's nearly always for images without large spaces like skies, but with animals in it, furry animals. They often reject for artifacts and give me "the problem" piece enlarged, so I can see which part of the photo is the problem. And it's always a part of the animal's fur.

cathyslife · « **Reply #12 on:** December 21, 2009, 11:21 »

Quote

No, sorry but wrong: Noise and artifacts are two completely different things.

Some degree of noise is totally acceptable if it fits the image and the base image is large enough - at 21 megapixels from the 5DII, I wouldn't consider the noise in the sky a big problem.

Here are two different definitions I found online, on two different sites:

Noise is apparent by the presence of color speckles where there should be none. For example, instead of a blue sky, you notice faint pink, purple and other color speckles amongst the otherwise blue sky.

ARTIFACTS - Sometimes spelled "artefacts" - Picture degradations that occur as a result of image-processing tasks, such as compressing an image which can result in an increase in digital "noise".

I have had rejections for both noise and artifacts. And though they may be two different things technically, and caused by two different things in camera, they both result in the same thing...distorted or odd-colored pixels in your photo.

As far as adding noise to reduce artifacting, I will have to try that. I have always added blur. Microstock sites are so paranoid about noise, I have never even thought of adding noise to get rid of something else...to me that doesn't make sense.

Maybe the microstock sites are a little more lenient on noise with photographers shooting with 5DIIs. I have never been shown any leniency when it comes to noise in my photos. Or for artifacts.

steheap · « **Reply #13 on:** December 21, 2009, 12:06 »

Quote

Some degree of noise is totally acceptable if it fits the image and the base image is large enough - at 21 megapixels from the 5DII, I wouldn't consider the noise in the sky a big problem. Question is why is the image shown here so small? Too much cropping?

The images on the site are around 9-10 mega pixels so I cropped them to around half size, but they aren't reduced or downsampled.

Steve

ap · « **Reply #14 on:** December 21, 2009, 12:28 »

Quote from: MichaelJay on December 21, 2009, 10:28

Some degree of noise is totally acceptable if it fits the image and the base image is large enough - at 21 megapixels from the 5DII, I wouldn't consider the noise in the sky a big problem. Question is why is the image shown here so small? Too much cropping?

wow, i'm really surprised you find that much noise in the sky acceptable. i don't think it would pass muster if it was one of mine. but where in the photo do you actually see the artifact? i honestly cannot see any when mine are rejected for it. i think i've gone blind from all the post processing work. thanx.

FD · « **Reply #15 on:** December 21, 2009, 12:38 »

Quote from: cclapper on December 21, 2009, 07:44

You have to be really careful about sharpening any photo, sharpening adds noise. Also, try always to shoot at ISO 100.

+1.

FD · « **Reply #16 on:** December 21, 2009, 12:42 »

Quote from: Anyka on December 21, 2009, 10:55

They often reject for artifacts and give me "the problem" piece enlarged, so I can see which part of the photo is the problem. And it's always a part of the animal's fur!

Maybe one of the reviewers has an allergy for cat fur.

m@m · « **Reply #17 on:** December 21, 2009, 13:08 »

Quote from: ap on December 21, 2009, 12:28

Quote from: MichaelJay on December 21, 2009, 10:28
wow, i'm really surprised you find that much noise in the sky acceptable. i don't think it would pass muster if it was one of mine. but where in the photo do you actually see the artifact? i honestly cannot see any when mine are rejected for it. i think i've gone blind from all the post processing work. thanx.

Even though artifact is really a part of some of the technical problems with some images rejected by IS, I've also notice that when they're not interested in the subject matter of the photo they tend to use it as an excuse to reject such, that's why in some cases is impossible to find the artifact they're talking about when you double check the image yourself at a 100%...hey if they found a tech problem, you should be able to see it too right!

ap · « **Reply #18 on:** December 21, 2009, 13:33 »

Quote from: m@m on December 21, 2009, 13:08

Even though artifact is really a part of some of the technical problems with some images rejected by IS, I've also notice that when they're not interested in the subject matter of the photo they tend to use it as an excuse to reject such, that's why in some cases is impossible to find the artifact they're talking about when you double check the image yourself at a 100%...hey if they found a tech problem, you should be able to see it too right!

well, i think that would be true if they also make it not possible to resubmit. however, many times, they offer that resubmit button like a throwdown, if only i can find the artifact...

Egypix · « **Reply #19 on:** December 21, 2009, 14:09 »

Yes Noise is very critical issue with istock but i have good photos at www.agefotostock.com some of it taken in iso 800 and iso 400 at night also.
(my photographer name @ agefoto is Wael Hamdan.

MichaelJay · « **Reply #20 on:** December 21, 2009, 14:39 »

Quote from: steheap on December 21, 2009, 12:06

The images on the site are around 9-10 mega pixels so I cropped them to around half size, but they aren't reduced or downsampled.

Yes but for the end use it's important which size the user can start with. If you only upload 10 megapixels, any noisy pixel will make a bigger part of the image rather than in a 22 megapixel image. So an M size image derived from 22 megapixels will hide the noise much more than an M derived from 10 megapixels. I hope I made this clear, at least that's how the content team has explained things several times at iStockalypses.

Quote from: ap on December 21, 2009, 12:28

wow, i'm really surprised you find that much noise in the sky acceptable.

Beware that I'm not an inspector and I have had my share of rejections (and still getting some...).

But I have found that inspectors are much more lenient on noise if it's in a 22 megapixel image rather than the 10 megapixel I had with my old camera. And believe me, I was exclusive at that time already, so this is not "because it's easier for me as an exclusive to get images through inspection".

In case of questions or problems with iStock acceptances, I really recommend iStock's Critique Request forum since there are quite a few inspectors around who are willing to help out finding issues and pointing how they can be solved.

FD · « **Reply #21 on:** December 22, 2009, 08:04 »

For the OP: on a snapshot here, I took the JPG (finest, all alterations off) straight from cam (5D-MKII) and blew the most unfavorable part with sky up, 100% and 500% (bicubic smoother). The image is even slightly underexposed with the histogram at the 10% right being flat. 1/512, F8.0, 100ISO.

Compare your bokeh around the flower's stalk which is also slightly out of focus with the bokeh here: it's smooth and gradual. No noise at all in the sky.

My bet is you pumped an underexposed shot up in the JPG. Even pumping up in RAW, distortions like in your shot are hardly possible. Just my 0.01$.

steheap · « **Reply #22 on:** December 22, 2009, 08:41 »

It makes me wonder if I have a problem with the camera! The shots were taken at ISO500 hand held using a 70-200 f4 lens with extenders. They are raw from the camera. I'll load the same files with no cropping and no "development" at all tonight - this is helping a lot, thanks.

Steve

FD · « **Reply #23 on:** December 22, 2009, 09:05 »

Quote from: steheap on December 22, 2009, 08:41

It makes me wonder if I have a problem with the camera! The shots were taken at ISO500 hand held using a 70-200 f4 lens with extenders. They are raw from the camera. I'll load the same files with no cropping and no "development" at all tonight - this is helping a lot, thanks.

iStock doesn't like processing, and I personally would avoid uploading anything above 200ISO. As has been mentioned, they are probably more lenient for images in the native cam resolution than downsized.
Just a sidenote: by using a monopod at less than 1/500, you can win 1-2 stops or bring down your ISO.

Just for a comparison, here another snapshot at ISO400. Same conditions as in the previous one, unaltered JPG straight from cam. F3.5, 1/50 handheld (you can see it on the blur and halo on high contrast edges of the balloons), ISO400, 24-70/f2.8 at 24mm (well outside the lens' optimum). A bit of noise, but no real artifacts. The original histogram is added.

Smithore · « **Reply #24 on:** December 22, 2009, 09:39 »

Noise and artifacts are very different, I have some pictures at 800 iso and even 1600 approved at istock and many 100 iso and no sharpening rejected for artifacts with 5D mark II.

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Author Topic: Artifacts at full size rejections at iStock (Read 23692 times)

steheap

fullvalue

kaycee

Gannet77

steheap

Eyedesign

borg

Opla

steheap

cathyslife

MichaelJay

Anyka

cathyslife

steheap

ap

FD

FD

m@m

ap

Egypix

MichaelJay

FD

steheap

FD

Smithore

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