Photos have ton of dithering?

I just checked some of my images and there is no "dithering" that I can see. From a variety of lenses with a Canon 20D and processed in PS, Aperture and iPhoto in sizes from 800 to 3500 pixels. Full zoom indicates some pixelation but otherwise sharp as can be.

What exactly are you seeing?

It's literally dithering, faint in most images but pronounced in areas with blacks and shades of gray. Unfortunately since we can't extract the photos from the iPhone, I can't determine exactly what's wrong with the image. The dithering is slight and for most people they won't even notice it. It just irks me since my 2 year old Sharp cell phone's screen seems to be a lot sharper. Again, I think it has to do with the iPhone screen not being true 16 million colors and iPhoto doing some poor optimizations when it sends the photos to the iPhone. All of which can be fixed in a software update.

I've got photos on my iPhone from a 20D, 5D and Leica M8. They look great. I think you are just expecting too much. Even though it's the NICEST and BIGGEST cellphone display by far and wide, it is still a mobile device that wasn't meant to optimize your photos the same way it would for a 30 x 40 print.

No one but the pickiest of people will even notice what you're talking about... and you're not going to be running a show from your iPhone. Be realistic and realize that the photos look extremely good for what they're being displayed on. It's not your expensive diamondtron monitor for crying out loud.

Mine look great too. Reduced from a 12MP Canon 5D.

But if you zoom them they do look dithered. SO yes I wouldn't mind a slightly higher resolution put on the iPhone. I assumed this was settable somewhere but have not looked. If not today it probably will be in the future.

With Vista I can put the files on in any size I want.

I've got photos on my iPhone from a 20D, 5D and Leica
M8. They look great. I think you are just expecting
too much. Even though it's the NICEST and BIGGEST
cellphone display by far and wide, it is still a
mobile device that wasn't meant to optimize your
photos the same way it would for a 30 x 40 print.

No one but the pickiest of people will even notice
what you're talking about... and you're not going to
be running a show from your iPhone. Be realistic and
realize that the photos look extremely good for what
they're being displayed on. It's not your expensive
diamondtron monitor for crying out loud.

I'm not being unrealistic. I have a few AU KDDI and Vodafone phones from Sharp and their screens are superior when it comes to viewing photos. I was trying to figure out why if they share the same pixel resolution as the iPhone, do photos not appear as sharp to my eye. I still think it's iPhoto's optimization during sync. It's downscaling the photo too far down for my taste and there's no way to tell iPhoto how much optimization I want.

Macbook Mac OS X (10.4.10)

Most reviews have remarked about how great the photos look and how they make the reviewer's cell phone images look like thumbnails. All I have heard when I show the photos to friends is how sparkling and crisp they look. Apple will also accept any size file during the sync process so Vista is not unique in that feature.

You may want to have your screen checked...perhaps there is a software bug or hardware deficiency in the iPhone you have.

I also see absolutely no dithering whatsover when I copy my photos over - they look amazing on my iPhone.

Could we be seeing differences based on those of us using Macs (me) and those of us who are using PC's? Just wondering.

I see the dithering. I'm on a Mac.

To those who think large image dimensions or high megapixels is a factor in seeing clear zoomed images on the iPhone, you are missing the key point here...iTunes' optimization method.

As long as the original photo is no smaller than the iPhone's screen, 320x480, most well exposed sharp photos will look reasonably clear with no zoom. You can take a photo with a 50 MP Hasselblad, 10,000x10,000 pixels, and it won't look any better or worse than the same image shot with a 5MP Canon Rebel on the iPhone. Nor will one zoom better than the other.

iTunes sizes any and every photo larger than 320x480 to fit the iPhone screen, possibly slightly larger to enable some zooming.

In fact, my theory is that perhaps those of us seeing obvious dithering are importing photos that are too large to begin with. If iTunes uses an agressive compression algorithim to get photos down to a specific dimension and/or file size, our megapixeled images may be suffering more optimization than folks with point and shoot cameras who import their pre-optimized pics at web-ready size, like 640x480.

I also wonder if those here seeing dithering are, like me, not using iPhoto to import the pics onto the iPhone. I have a folder I toss images into from Lightroom, that I use for a variety of purposes. Maybe iPhoto-optimized images are already optimized enough that iTunes doesn't need to spray them with dither.

Hmm, I've never used iPhoto on my Mac in my life, and I see no dithering at all. All of my imported photos have been taken with a 10 MP Nikon D200, saved as JPG very few resized from the originals. They are crystal clear on the iPhone.

Interesting that some see it, some see none of it.

Wonder if this is:
- Differences in screen imperfections causing this on the iPhone?
- Differences in post processing pre-import? Maybe somehow dealing with how iPhone optimized images that have been converted from Raw? I don't use raw, just pure JPG.
- Differences in other post-processing techniques? Could photos that are over-sharpened, or levels changed significantly, or colors saturated be optimized differently?

Maybe it's related to nothing, just better optimizing on some phones and worse on others?

UPDATE Well there goes my theories. I just resized a 4000x6000 jpg to 50%, used iPhoto to sync both the original and the resized copy to the iPhone and they are 99.9% identical, and both have pronounced softness and dithering when zooming.

I wonder if those who are seeing dithering and those who aren't are seeing the same thing, and either don't know it or don't care. The zoomed images look ok, but I would certainly not describe them as "pristine".

"I think those who are seeing dithering and those who aren't are seeing the same thing, and either don't know it or don't care."

I would take exception to that. I've been doing professional photography for years and I do NOT see the "dithering" described herein.

I was a freelance photo assistant for 10 years, and worked for over 100 different photographers before turning to retouching. I can assure you there are plenty of professional photographers who don't see the same things as the next one.

The only real way to know if we're seeing the same thing in a different way would be fill a room with photographers/iPhone users, give them all the same photo, then pass the phones around and note any differences.

It seems to be an issue with Mac users using iPhoto. All the PC users say the images are crystal clear. May I inquire how PC users are getting their photos into iPhone?

It may be a Mac thing, but until my little test, I wasn't using iPhoto. I was just syncing to a folder on my desktop.

Prosumer photographer here, own Nikon D1, D2H, D2X, D200, and Leica C-LUX2.

I manage photos in Aperture with JPEG originals and RAW originals, from all those cameras. My wife shoots D200 and Sony DSC-T9, and uses iPhoto.

When iTunes resizes the photos for the iPhone, it dithers them, much as if the photo was being made into a PNG file with fewer colors than the screen supports (i.e., thousands instead of millions, but nowhere near as bad as a 256 color GIF). This applies to both her photos via iTunes from her iMac, and my photos via Aperture on a Mac Pro.

The same photos, when viewed from a web page through Safari, show no dithering whatsoever. The built-in wallpapers that shipped with the iPhone, do not exhibit this dithering.

From these observations, it seems there is, without question, something wrong with the way iTunes resizes the photos for sync to the iPhone. This problem occurs in our two phones and in four phones belonging to colleagues at the office. (Note that I have not looked at an iPhone synced by a PC user.)

However, it's not that bad. I worked in the printing side of the publishing industry starting in 1983, and was one of the first who consulted to pioneering "all digital" professional printing companies on how to manage quality control throughout the digital workflow. Based on that experience, it seems readily apparent to me that the iPhone sync is dithering colors--but I'd wager most people will not notice it because this screen is 160 pixels per inch.

(a) G5 Quad; (b) Mac Pro; (c) iMac G4; (d) iMac 24" Mac OS X (10.4.7) (a) 6.5 GB, Apple 30" + Cintiq 21; (b) 4 GB, Dell 30" + Samsung 215TW