Wavy Lines - S5IS

[odin7]

I have noticed that there are times when straight lines and edges become wavy in pictures taken with my S5IS, especially at full telephoto magnification 48X. The attached pictures were taken 1 minute apart. Note how the handrails are straight in the first shot and wavy in the second. The only difference is that the first shot was taken at 1/1000 sec and the second was 1/636. Since the mode was Program, I presume more light was needed since the darker shape of the man was added to the frame. I also have some telephoto shots of buildings, where all the edges look wavy too. Otherwise the pictures look in-focus. How do I prevent this effect in the future? Thanks.

Just a thought - Is there some sort of interlaced versus progressive data collection of the CCD going on here? So if camera shake (even with the IS on) is on the order of the scanning, then the image from one row of pixels would be slightly shifted from the next and you get this pixel line to pixel line smearing effect?

[JustShootin']

Do you have the quality setting set to large and fine? Digital zoom could also be part of your problem. Remember, when you use digital zoom, you're really only cropping, and lowering photo quality. I leave my digital zoom turnd off period.

Gary

[MikeD2203]

Are you taking these photo's hand-held? I have an S5 and still learning but I have not come across this yet. Full zoom is really going to need a tripod to be sharp, The rest of the photo looks clear but I think using a tripod if your not now might help.

[odin7]

No tripod - I was on a boat - I guess I'm expecting too much of the IS system, yet the first picture was OK.
I checked the quality setting - Large and Fine - Yes

[JustShootin']

You can get great photos at full zoom, and handheld with good light. But as I mentioned, go easy on digital zoom, or better yet, turn it off.

Gary

[odin7]

A blowup of the undesirable effect. Shouldn't all the pixels blur uniformly if it were simple camera shake?

[JustShootin']

Once again, I believe if you make sure your digital zoom is turned off, you have your quality setting on high and fine, and use the lowest ISO setting, which I believe is 80 on the S5 this problem will go away. Yes, a tripod is a good idea for long zoom, but not always a must. This doesn't appear to be camera shake to me. The photo's not really blurry, but it sho nuf do have digital noise.

Gary

[odin7]

I hear you. The problem is I just Luvvvv those 48X telephoto shots. :)

[codex0]

Heat waves?

[odin7]

It's a thought, but these pictures were taken only 1 minute apart shown by the time stamp.

[Jon]

It's the image resizing from the digital zoom. As said, turn it off, and do your cropping and enlarging in post-processing; you'll be able to control this kind of thing better there.

[odin7]

Jon -
Could you elaborate on how "image resizing" takes place in the camera? Both pictures were essentially the same. One had the problem, the other didn't. What was different? As to not using the digital zoom range, I guess I conceptually have trouble with turning off a feature that Canon has offered me in a camera as a solution to a functional problem with that camera. :( For sure, a 48X zoom was a selling point. As a direct comparison, here is a blowup of the "good" shot. Absolutely no wavy lines or edges -

[Jon]

It's going to depend on the angle the edge is at and the exact magnification you use. If you use digital zoom, each real pixel has to get broken up into several smaller fake pixels. Around the edges they average adjoining ones, so what any fake pixel ends up as depends on what the real pixels nearby contributed to it. Remember, at 48x total zoom on a 12x lens, you're only using 1/16 of the pixels in your sensor to get the picture, so to get a "full resolution" picture each pixel's split 16 ways, with "assists" from the 8 surrounding pixels. Essentially, the camera makes the transition from the raw sensor data to a final JPEG with digital zoom worked in in one step; if you do it in post-processing, you can take it in smaller steps, so the process is more forgiving.

"Digital Zoom" is one of those things that's used as a marketing tool, like how many "x" your zoom lens has (a meaningless number, really, until you say what the 1x you're starting from really is), or how many megapixels your sensor has (or how many gigabytes are on that card; a marketing gigabyte is about 7% smaller than the gigabyte your computer or camera thinks in).

[odin7]

Jon -
Very good explanation. Thanks, I can understand that. Oh well, life is full of compromises. ;)

[JustShootin']

Jon -
Very good explanation. Thanks, I can understand that. Oh well, life is full of compromises. ;)

I bet it is a good explanation. I wouldn't know for sure. But one thing I do know, and said it two or three times. If you want decent pictures, turn the dang digital zoom off! ;)

Gary