Digital Camera Excessive Pixilation - suggestions?

In My Humble Opinion (IMHO)
#1

My Dad’s always sending us these incredibly grainy pictures that he shot with his 6 mg pixel camera.

I thought he was achieving this effect via Photoshop Elements, as he’s given to excessive pfutzing around.

He explained the other day, though, that the problem is with digital photography. Apparently all cameras shoot 42" pictures at 75 dpi (or something like that). So that when he crops them, he winds up with graininess.

I haven’t had this problem with my camera (which is 3 mgpixels, I think). But I always change mine to 300 dpi, and usually bring them down to 8" x 10" or so.

He tends to email really large pictures - like, they extend beyond the screen.

Any ideas as to what’s going on?

Any way I can break it to him gently?

#2

His digital camera’s quality settings are turned way down, or he’s super-enlarging them on the computer to some unnecessarily high resolution, or both.

His comment about digital cameras, by the way, is pretty much pure bullshit. The final image resolution of digital cameras depends on the sensor, i.e. the number of megapixels. A one megapixel camera will give you an image resolution around 1600 by 1200.

Internally, most cameras will apply a setting of 72 DPI, but that is meaningless for on-screen viewing. DPI only matters when a physical medium is involved (either printing or scanning), and your DPI settings will determine the final image size on paper. The image resolution will determine the overall quality. For example, if you specify 300 dpi, you will end up with a size of 4x6 or so for a one megapixel camera. Specify a smaller number of DPI, and you will appear to enlarge the image on paper but you will get less apparent quality because you are stretching the image out. Increasing the DPI to something extreme, like 1500, will only serve to cause the image to print extremely small, as you are telling your printer to pack that many pixels into an inch.

#3

Forgot to add that most cameras offer smaller sizes than full sensor resolution. My digital camera allows me to choose sizes like 640x480, 1024x768, and some other smaller sizes up to the full five megapixel size. The camera captures at full resolution then scales down to get the desired output. Some people choose those sizes because they can fit more pictures on a card at low settings, but don’t realize they are taking pictures unsuitable for printing.

#4

As Cleophus said, dpi is meaningless when it comes to online viewing. For printing photos, 300 dpi is ideal, but you can get away with 200 dpi at smaller print sizes.

If he wants the best quality out of his camera, He should take photos at the full 6 megapixel resolution (around 3000 x 2000 pixels) which will yield very good 8" x 10" prints. These originals should then be archived.

Then, if he wishes to re-size the photos for web or email viewing, he should open up Photoshop Elements and use the re-size option under the Edit menu, choose the Bicubic Sharpen method of interpolation, set the resolution to 800x600 or maybe 1024x768 max. and he’s done. Also, I believe that there’s a batch tool in Elements that he could program to re-size multiple photos at once. Fair Warning: He should NEVER edit his original files but always work on copies, instead.

This method will maximize photo quality and reduce to a minimum any visible pixelization.

#5

Thanks for the explanation - I’m almost following this (something about photography just makes me go blank - I’ll never “get” f-stops).

It’s in the printing that the image quality problem is really apparent. He thinks it’s b/c “the bigger you print, the more the flaws show up.”

So - if you’re saying 1600 x 1200 is what a 1 mgp camera produces, then @75 dpi the picture is going to be roughly 16" x 21"? And when I change it to 300 dpi (which I’d always heard is about the highest dpi home printers need), I’m making the image (roughly) 4" x 5"? And keeping the image integrity (without making an unnecessarily large file that takes up more memory)?

I just looked to see what he’s sending and they’re 300 dpi. I’ll bet he’s changing the dpi without letting it re-size & that’s why the pictures are so grainy and flat.

#6

Is he shooting a lot of low-light pictures, perchance? The sensors in most consumer digital cameras have a lot of noise in dim light.

#7

“Bicubic sharpen method of interpolation” ----> ooh, he’ll like that, sounds technical!! Thanks for the suggestion, I’ll pass it along.

I’d like to just watch him do this sometime & see exactly what’s going on.

#8

No, actually it’s his outdoor photos that are the worst. He loves to shoot birds in flight and really small animals & amphibians.

#9

There’s a big clue. In those sorts of photos, the subject is only going to be a very small part of the total image area. If he crops the unwanted part, then resizes back to a large size, the image can easily turn out grainy. Imagine resizing a 320 x 240 video clip to 800 x 600. The DPI resolution is going to make no difference in the final image’s graininess. There just isn’t enough information in the original to give a smooth image.

If the original 6M pixel image is 3000 x 2000, but you crop so there are only 300 x 200 pixels left, then resize back to a screen size, say 800 x 600, you’ve made your pixels cover 800/300 x 600/200 their original area, 2.66 x 3; in other words, each pixel in the original becomes 3 in the resized image. If you make the final image even bigger, which he may be as you say they extend beyond the screen, so they exceed your screen size, then the graininess will be even worse.

Just my take on the possible cause.

Cheers,
Kiwi Fruit

#10

If you find out what model camera he has, odds are we can find an online manual and get pretty exact instructions on fixing this.

#11

Is he using digital zoom? Digital zoom isn’t really zooming at all, it’s just the camera cropping out part of the image and blowing it up, leading to crappy results.

#12

Huh - interesting! I didn’t know that about the zoom!

Funny thing about reading the manual – he’s convinced he knows everything about photography. And his results are frequently awful; when this man dies, I’m going to inherit roughly 3,765,981 blurry photos.

It’s a touchy subject for me, since I did go to ART SCHOOL for a few years. He never asks my opinion on his work, he just wants praise. The subject only came up b/c he was lecturing me on the shortcomings of digital photography, and what he was saying didn’t match my experience with my (cheaper and less elaborate) camera.

#13

Yes, digital zoom is crap. Optical zoom is the only thing worth looking at. When you first open the camera, turn of digital zoom and never look back.

Actually, there are some uses for digital zoom, mainly with video, but I digress.

Your dad is clearly doing something wrong, since it’s pretty easy to take good digital photos with any 6 MP camera that look fine on a computer monitor. There are several things he could be doing wrong, including excessive cropping, digital zoom, poor use of image editing software, poorly chosen camera settings.

#14

What is his camera make and model?

#15

digital zoom and cropping have been covered as has shooting in a lower setting. A longshot problem is also compression. If he is resaving the image to a new name (likely if he is cropping) he may be compressing them by accident. I have software that remembers the last save-setting and if I compress a jpg image it will stay at that setting.

It could be a combination of all of the above. Shooting at a lower resolution while digitally zooming and then cropping. You’d end up with crap doing this.

#16

I dunno - he’s actually bought several over the years. One of them fit into an Altoids box, he loved that. Don’t know if he still has it.
I was picturing you in a cop’s uniform - “Just the facts, ma’m. Can you give me his make and model? We need to get this offender off the Photoshop.”

#17

fessie, you may be able to tell which camera he’s using strictly from the JPGs that he’s sending you. Most modern digital cameras embed information about the manufacturer, model, date, time and camera settings (aperture, shutter speed, focal length, ISO) within the file. It’s called EXIF data and can be read by most image viewing programs. Unfortunately, this data is sometimes deleted by rogue image editing programs but it might be worth taking a look.

Also, it might be helpful if you were to post some of his photos online for us to take a look. There are quite a few free web-based image hosting sites available. My own favourite is Flickr. As an added bonus, Flickr can read EXIF data and display it in a handy link beside the posted photo.

#18

Oh, you’re right Hodge - and I’ve even noticed that before. Duh!

OK – it’s a Pentax Optio SV.

He sent me a 2241 x 3000 image that’s 1.70 mg, 7.47" x 10", 300 dpi. It has the same curious flatness and blurriness as the ones he prints out (although it’s not as pixilated). Tellyawhat – I’ll post it to the twins’ website & give you a link!. It’s the second photo - I cut it until I got down to 500 dpi, which is the website’s limit.

It was a picture of my dh tossing our dd into the air, which is probably not the easiest thing to photograph, but this is the problem I keep seeing.

#19

He actually took all 3 of those photos – I thought the first one turned out pretty well. The colors on the last one creep me out.

I hope I don’t sound like a total ingrate, I do appreciate his taking photos of the kids. It’s just that he acts like he’s a World Expert on photography & I don’t think the results are anywhere near that calibre.

#20

Well, the Optio was never a great camera. Image quality suffered greatly by stuffing everything into that form factor. Those pictures are hard to judge. The middle one looks out of focus, the top one has too slow a shutter speed to freeze the action.