CS5 extended - prob when converting psd to jpeg or pdf

[bmatlock1942]

When I convert a psd file to jpeg or pdf, I see distortion/poor resolution in a blue sky. Looks like wavy lines. At actual pixels, looks like splotches. On jpegs, the distortion gets less as I increase the quality setting and goes away on the max setting. Have tried flattening the image. Same result. Thanks!

[Hoogle]

well obviously if your lowering the quality compressing millions of colour and data pixels you are going to get halo type effects unsmooth colour changes etc. however a full quality jpeg is going to be no where near the size of a full quality psd

[bmatlock1942]

I'm doing a powerpoint presentation with 200 images & was trying to use small file sizes. I'm only having this problem with images having a bright blue sky. I don't see it anywhere else. I can understand an overall degradation of resolution depending on the jpeg/pdf quality chosen, but not the irregular splotching just in the deep blues. So it's not obvious to me.

[Zeealex]

why don't you save it as a PNG it should be a smaller file size.

[bmatlock1942]

The PNG file works but it's 7 times larger than the best quality Jpeg which also works. The high quality jpeg is a work around for me on those images with bright blue skys but still don't understand the original issue with lower quality jpegs & pdfs. Thanks!

[Poxt]

What is the output application your pdf? meaning what will you use this PDF for? Print, web, blast, e-mail,?

[Poxt]

Sorry, I see your using for powerpoint presentation.
I never use PNG's or PDF's for powerpoint. I use JPEG's - RGB mode - at about 96-110 dpi - make sure the size is 1:1 actual.
There could be several reasons for the banding in the sky.

Find out what the source image size, mode, and dpi are.

[bmatlock1942]

I use Nikon Raw, 2848x4288, 240ppi, RGB Adobe 1998. Ended up doing a Bridge PDF slideshow because of file size & used high quality Jpeg for the ones I was having trouble with. Thanks!

[Poxt]

Okay, well obviously your images are banding, without seeing your overall PS settings I can't trouble shoot.
Google a query for "PS image banding when imported to Powerpoint"

Read on this and you will find several solutions that should get you on track asap.