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Strange pixel effect on all photos

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DistantMelody
Member

Strange pixel effect on all photos

Hello everyone :slight_smile:

I have a Sony SLT-A77V camera. I nearly always use a tripod and a remote control for added steadiness. I have a polarizer for the nice deep blue sky effect. I can always see a pixel effect on my photos. Here is one as an example:

https://www.facebook.com/photo.php?fbid=648980398470611&l=90284b1105

Close up:

https://www.facebook.com/photo.php?fbid=648981998470451&l=df5f54c211

 

It is rather upsetting when I do my best and get these results. What could be the reason?

I wanted to go into Stock photography but it turns out they are quite particular about this sort of thing and my images wouldn't be acceptable due to the pixel effect.

Please help me to fix this problem.

DistantMelody

40 REPLIES 40
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DistantMelody
Member

I have been looking at the Sony website and I saw there is an image where they also have the grainy pattern. Please scroll down to the picture of the seagull.

http://www.sony.co.uk/electronics/interchangeable-lens-cameras/slt-a77

Is it something normal or because they enlarged the image to over 100%?

Bieomax
Member

aye it could well be

 

Now that you've got the adobe camera raw, have you played with the noise reduction within that?

 

You may find that the noise is acceptable, i dont often do much noise reduction at iso100, and use it more when i've had to use higher ISO's to being down the levels to what i deem acceptable.

 

but if your doing stock photography its something you will learn as it will very from agency to agency.

 

Also if your on the A77 camera you have a 24mp file, there is nothing stopping you reducing the final edited images down say i 20mp as the resize can also help (just becareful to maintain your DPI for stock, as 72dpi is pretty much all you see on a internet page/monitor or projector, where as if you wanted to print it large you want it at 300+ so the stock agency will want them high as possible)

 

here are some details from Istock (getty images)

 

Noise & Compression

Here

 

Noise Reduction Tips

here

 

and another random article

Here

 

i think the best thing you can do is get a load of images ready for submission and see what they say, take feedback if rejected and work on what they tell you

 

Also a handy link for general editing of photo's covering lots of handy information

Here

 

 

Let us know how you get on

 

 

Mark.

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james.billings
Member

In your first images I'm seeing posterization, not pixellation. This is where the blue sky is seen as distinct blocks of colour rather than a gradual tone. 

This is a JPG compression problem - if the camera was set to JPG then make sure you're on the highest quality setting. Preferable is to use RAW, and then when converting, pick the highest JPG output setting. 

 

For the castle you posted yesterday, the "grain" you see is just normal noise, and not unusual. I'd say the focus is slightly off (the brickwork isn't pin sharp), but that's a different issue. The shot also looks a little underexposed- ideally, you want to "expose to the right" so the image looks a bit too bright to begin with. Once you lower the brightness down to your intended exposire, you will reduce noise too. If your camera has a histogram feature, then exposing to the right can be done by increasing the EV as high as it will go without it bumping into the right hand side. See http://en.wikipedia.org/wiki/Exposing_to_the_right

 

 You can lower the graininess with some noise reduction software- I use the noise reduction built in to Lightroom, not sure if whatever you have offers something similar? 

Unlike a simple "soften" which will soften everything, a good noise reduction algorithm will be frequency aware and work more effectively at lowering the graininess while keeping detail.

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DistantMelody
Member

Thank you Mark :slight_smile:
You've given me a lot of information to absorb. I read in the terms that the particular website I joined don't accept reduced images.
How can I check the DPI?
Which noise reduction do you mean? I tried the layering which is photo 3 on my previous post. The flag was blurred, though, because it kept moving between shots. Did you mean there is another method?
Thank you,
DistantMelody
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DistantMelody
Member

Thank you James :slight_smile:
I will use only RAW from now on. Did you mean the castle itself was too dark? I used a polarizing filter for the dark blue sky. I didn't know anything from the wikipedia artcile. I have a lot to learn. :slight_smile:
I don't know of any built in noise reduction in Photoshop Elements. I tried blurring and layering only. I don't have Lightroom.
Thank you,
DistantMelody
Bieomax
Member

I've just Googled photoshop elements and from what I've seen and read the Adobe camera raw is cut down alot in elements when compared to full photoshop or lightroom. Which in them versions adobe has its own noise reduction set of options within the raw windows.

I know my father has just recently got lightroom for his pc and if I recall correctly he paid about £80 for it from Adobe. I'd maybe have a look at playing about with a trial of lightroom and see how you get on with it

As it's a dedicated programme for photographers and for working with photographs.

Mark.
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DistantMelody
Member

Hello Mark

I will have a look at Lightroom. It might be better than what I have now.

I uploaded 5 images to Alamy as a test submission. They say that if 1 of the images is not up to their standards all images fail. They wrote that all 5 failed but only put reasons for 2 of them. I am confused if that means the other 3 were ok but only failed because of the other 2 or were they also not right? They said it was poor exposure for 1 of them and chromatic aberration for another. It is obviously not for me because I cannot see that one image is too dark and I can't see any cyan spots on the other. This is when the photographer stops being the artist and becomes a grey employee. 😞 It's not for me. But I would like to know where the aberration was because I can't see it. How do I find it? They said: Chromatic aberration or ‘coloured fringing’ is shown as magenta/green or red/cyan fringing in areas of an image that have greater contrast. Poor quality optics and extreme wide-angle lenses tend to show Chromatic Aberration especially towards the edge of the frame. To remove this you can use the Chromatic Sliders in the Lens Correction Tool in Photoshop, most RAW conversion software has a similar tool.

DistantMelody

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james.billings
Member

Can you post a link to the full-size image they complained about CA on? Hopefully we can spot it and point it out.

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DistantMelody
Member

Hello James

I have found that flickr has full-size image viewing capabilities.

This one is the one they said has Chromatic aberration:

https://farm8.staticflickr.com/7265/13407962545_5836d43cbc_o.jpg

 

This one they said has bad exposure, but why? To me it looks great. I always max out the polarizer for the darkest possible skies.

https://farm3.staticflickr.com/2820/13407956955_d66e16ae71_o.jpg

 

Please say if the links don't work.

DistantMelody

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james.billings
Member

Thanks for those links, worked fine.

 

The CA is easy to spot I'm afraid! See the example crops below- the CA is the purple/green edging.

 

 

ca1.png

 

ca2.png

 

As an experiment I dropped the file into Lightroom and turned on the option to remove CA and it does a decent job:

 

13407962545_5836d43cbc_o.jpg

 

 

The other image is indeed a bit underexposed. The histogram doesn't go above the 2/3rds point: 

 

hist.png

 

I increased the exposure/contrast/vibrancy and dropped the highlights a little:

 

13407956955_d66e16ae71_o.jpg

 

Hope that helps a bit!