Steve'sDigicams

NHL · Apr 24, 2003, 1:41 PM

I think they are talking about digital zoom before the "jpeg"ing which is probably valid for some cameras without raw output. Digital zoom from a compressed jpeg in post process is probably 'not as good' as in-camera and will be debatable for a long time. :?

The s602 is probably a best example of this @ the 6Mp setting... ie you probably get a better picture out of the camera than if you digital zoom the 3Mp jpeg(or tiff) output to a 6Mp picture resolution afterward. (Not that the diagonal Fuji's sensor also help) 8)

normc · Apr 24, 2003, 1:46 PM

I am enjoying the discussion...and some of the assumptions as well.

jawz · Apr 24, 2003, 8:49 PM

The technical discussion is very interesting to me and worthwhile continuing in that vein. However, as a side note, I don't use digital zoom with my c3020 since (obviously) it requires that I rely on the LCD for framing the shot. When I'm after a hand held long (lens) shot, I need to have the camera steadied by the poor man's tripod--both elbows-to-ribs and camera to the face. I can do this pretty well when using the optical viewfinder, but I have a hard time keeping camera shake under control without the third point (face) of the tripod when using the LCD to compose/frame the picture at max opto-digi tele.

...but maybe its just shaky ol' me?

eric s · Apr 24, 2003, 10:08 PM

NHL,

What you said here:

Quote:

The s602 is probably a best example of this @ the 6Mp setting... ie you probably get a better picture out of the camera than if you digital zoom the 3Mp jpeg(or tiff) output to a 6Mp picture resolution afterward. (Not that the diagonal Fuji's sensor also help)

seems to suggest that using the tiff from the s602 would be no better than the jpeg. Steve's review says that the tiff is uncompressed. So why do you say what you said above? It isthat the digital zoom works on something closer to the raw sensor data? (before white balance and sharpening, for example.)

KCan · Apr 24, 2003, 10:09 PM

Quote:

Originally Posted by jawz

...but maybe its just shaky ol' me?

Jawz
I have exactly the same feel . With my film SLR, I am comfortable at long zoom. With my D7i, because I prefer the LCD over the EVF, I loose some firm grip control, I use my monopod much more often with my D7i than with my film SLR.

NHL · Apr 25, 2003, 5:24 AM

Eric

What I meant was if you took a 3Mp tiff (or jpeg) picture and try to interpolate it to a 6Mp in post process, it won't be as good as 3Mp picture processed in the camera to 6Mp, in agreement with Steve's. BTW some previous s602 threads have also demonstrated this regardless of the file type. Tiff output is always better than jpeg in any camera, but that's not what we discussed (ie in-camera vs post-process)!

IMO this example illustrates a 2x digital zoom perfectly from a 3Mp camera without raw output. With tiff the color resolution is already truncated by the camera, and with jpeg you have to deal with the compression on top of it as well, whereas the camera has access to the entire bits plus their full raw resolution. Like Normc has mentioned there's also exposure info and other parameters from the CCD that the camera has accessed to but lost when the picture is reduced to jpeg(or tiff) file with exif info! :?

normc · Apr 25, 2003, 7:38 AM

Whatever the digital zoom on a camera is it should be well done as a part of the overall design features. When we see a sticker on the side of the camera that says 36x zoom or the like, I think there should be an explaination as to it's functionality. I have a 10x optical zoom camera that I have never used the digital zoom feature. I also have a 5x optical zoom camera that I occaisionally have used the digital zoom feature. When I get to 36x zooms, give or take some, I would like to know something about the firmare in the camera that makes it "for real". Otherwise if it is just a simple crop then it does insult the customer.

Mike_PEAT · Apr 25, 2003, 10:29 AM

Quote:

Originally Posted by normc

When we see a sticker on the side of the camera that says 36x zoom or the like, I think there should be an explaination as to it's functionality.

I know on mine it said 27x zoom, 10x optical and 2.7x digital (from memory, I'm not one of those people to leave the sticker on the camera).

Abner101 · Nov 13, 2005, 5:55 PM

:? I believe that all reviews online discourage the use of digital zoom and your raising a very good question here. I see that most users in hear are of the DSLR type and have a viewpoint from only that side of the fence. Consider this............ I have a Kodak DX4330 3.0 MPix which compresses the daylights out of all my pics. I have no options for TIFF or RAW. Typical file sizes at the best quality setting is about 500k. These fotos make wonderful prints but zoom in just once and it looks like a picaso painting.

Now I ask you, is it better to use on camera digital zoom which I assume is done before the JPG compression or to fight with the JPG on the PC?

Daniel T · Nov 15, 2005, 4:42 PM

This thread caught my interest, so I decided to perform a real-world test of my Canon A510's digital zoom. I used my camera's highest resolution and lowest compression settings, and formy subject I chose a page from a book (black text on a soft white background) at a distance of 10 feet. Shot #1 was taken using only the 4x optical zoom, and Shot #2 included the camera's maximum digital zoom for a total of 13x.

I downloaded both images onto my PC and compared them side-by-side. I displayed Shot #2 (the digitally zoomed image) at100%, and I used my image-editing program to zoom Shot #1 (the optical-only image)4x so that it's text was approximately the same size as Shot #2, thus basically performing the crop on my computer rather than in the camera.

Results: Image #2 (digitally zoomed) was a bit darker overall, but it showed noticeably better detail. Also, there werefar fewer digital artifacts (from in-camera sharpening?) along the edges of each character of text. I also noticed that the pixels on Image #2 were much smaller when comparing the two images in this manner (and I assume that my camera created the extra pixels via interpolation).

I have to admit I was surprised by the results. Prior to this test I had just assumed that the digital zoom was merely an in-camera crop that would only be useful for those without computers or editing software.

However, I'm just an amateur digital photographer, sothese results are hardly definitive. Perhaps somebody who knows what they are doing and has better-trained eyes would care to repeat this test under more controlled conditions?

Apr 24, 2003, 1:46 PM	#12
normc Senior Member Join Date: Jun 2002 Posts: 394	WOW I am enjoying the discussion...and some of the assumptions as well.

Apr 25, 2003, 7:38 AM	#17
normc Senior Member Join Date: Jun 2002 Posts: 394	Another thing Whatever the digital zoom on a camera is it should be well done as a part of the overall design features. When we see a sticker on the side of the camera that says 36x zoom or the like, I think there should be an explaination as to it's functionality. I have a 10x optical zoom camera that I have never used the digital zoom feature. I also have a 5x optical zoom camera that I occaisionally have used the digital zoom feature. When I get to 36x zooms, give or take some, I would like to know something about the firmare in the camera that makes it "for real". Otherwise if it is just a simple crop then it does insult the customer.

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Apr 24, 2003, 1:41 PM	#11
NHL Senior Member Join Date: Jun 2002 Location: 39.18776, -77.311353333333 Posts: 11,599	I think they are talking about digital zoom before the "jpeg"ing which is probably valid for some cameras without raw output. Digital zoom from a compressed jpeg in post process is probably 'not as good' as in-camera and will be debatable for a long time. :? The s602 is probably a best example of this @ the 6Mp setting... ie you probably get a better picture out of the camera than if you digital zoom the 3Mp jpeg(or tiff) output to a 6Mp picture resolution afterward. (Not that the diagonal Fuji's sensor also help) 8)

Apr 24, 2003, 8:49 PM	#13
jawz Senior Member Join Date: Dec 2002 Posts: 430	The technical discussion is very interesting to me and worthwhile continuing in that vein. However, as a side note, I don't use digital zoom with my c3020 since (obviously) it requires that I rely on the LCD for framing the shot. When I'm after a hand held long (lens) shot, I need to have the camera steadied by the poor man's tripod--both elbows-to-ribs and camera to the face. I can do this pretty well when using the optical viewfinder, but I have a hard time keeping camera shake under control without the third point (face) of the tripod when using the LCD to compose/frame the picture at max opto-digi tele. ...but maybe its just shaky ol' me?

Apr 25, 2003, 5:24 AM	#16
NHL Senior Member Join Date: Jun 2002 Location: 39.18776, -77.311353333333 Posts: 11,599	Eric What I meant was if you took a 3Mp tiff (or jpeg) picture and try to interpolate it to a 6Mp in post process, it won't be as good as 3Mp picture processed in the camera to 6Mp, in agreement with Steve's. BTW some previous s602 threads have also demonstrated this regardless of the file type. Tiff output is always better than jpeg in any camera, but that's not what we discussed (ie in-camera vs post-process)! IMO this example illustrates a 2x digital zoom perfectly from a 3Mp camera without raw output. With tiff the color resolution is already truncated by the camera, and with jpeg you have to deal with the compression on top of it as well, whereas the camera has access to the entire bits plus their full raw resolution. Like Normc has mentioned there's also exposure info and other parameters from the CCD that the camera has accessed to but lost when the picture is reduced to jpeg(or tiff) file with exif info! :?

Nov 13, 2005, 5:55 PM	#19
Abner101 Junior Member Join Date: Oct 2005 Posts: 6	:? I believe that all reviews online discourage the use of digital zoom and your raising a very good question here. I see that most users in hear are of the DSLR type and have a viewpoint from only that side of the fence. Consider this............ I have a Kodak DX4330 3.0 MPix which compresses the daylights out of all my pics. I have no options for TIFF or RAW. Typical file sizes at the best quality setting is about 500k. These fotos make wonderful prints but zoom in just once and it looks like a picaso painting. Now I ask you, is it better to use on camera digital zoom which I assume is done before the JPG compression or to fight with the JPG on the PC?

Nov 15, 2005, 4:42 PM	#20
Daniel T Member Join Date: Mar 2005 Posts: 44	This thread caught my interest, so I decided to perform a real-world test of my Canon A510's digital zoom. I used my camera's highest resolution and lowest compression settings, and formy subject I chose a page from a book (black text on a soft white background) at a distance of 10 feet. Shot #1 was taken using only the 4x optical zoom, and Shot #2 included the camera's maximum digital zoom for a total of 13x. I downloaded both images onto my PC and compared them side-by-side. I displayed Shot #2 (the digitally zoomed image) at100%, and I used my image-editing program to zoom Shot #1 (the optical-only image)4x so that it's text was approximately the same size as Shot #2, thus basically performing the crop on my computer rather than in the camera. Results: Image #2 (digitally zoomed) was a bit darker overall, but it showed noticeably better detail. Also, there werefar fewer digital artifacts (from in-camera sharpening?) along the edges of each character of text. I also noticed that the pixels on Image #2 were much smaller when comparing the two images in this manner (and I assume that my camera created the extra pixels via interpolation). I have to admit I was surprised by the results. Prior to this test I had just assumed that the digital zoom was merely an in-camera crop that would only be useful for those without computers or editing software. However, I'm just an amateur digital photographer, sothese results are hardly definitive. Perhaps somebody who knows what they are doing and has better-trained eyes would care to repeat this test under more controlled conditions?