Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old Dec 12, 2003, 8:24 AM   #11
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Eric:

The Kodak model he has allows you to select resolution only, not JPEG Compression.

As far as noise reduction. The aperture/shutter speed indicated that the lighting was very good. That's why it selected a mid range F5.6 aperture, at an extremely fast shutter speed.

If lighting would have been low, it would have used a much wider aperture (larger F-Stop Number), and a much slower shutter speed.
JimC is offline   Reply With Quote
Old Dec 12, 2003, 8:45 AM   #12
Senior Member
 
Join Date: Mar 2003
Posts: 438
Default

I am not an expert but I agree with the JPEG compression theory here. I have a Kodak DX4330 that seems to have high JPEG compression too. Image sizes are about the same as mentioned here for the highest resolution mode. When I look at my pictures at 100% I see a lot of artifacts and what seems to be noise. Yet, when printed (at a photo lab), the same pictures come out very sharp and with nice color saturation. I have printed mostly 4x6 but I have also printed a couple of 8x10 and 5x7 with the same good results. Also, when resized on the screen, those artifacts are normally not visible either.

I learned not to worry about it. My advice: don't look at the pictures at 100% magnification. :lol:
luisr is offline   Reply With Quote
Old Dec 12, 2003, 2:32 PM   #13
Member
 
Join Date: Nov 2003
Posts: 49
Default

Quote:
Originally Posted by luisr
I am not an expert but I agree with the JPEG compression theory here. I have a Kodak DX4330 that seems to have high JPEG compression too. Image sizes are about the same as mentioned here for the highest resolution mode. When I look at my pictures at 100% I see a lot of artifacts and what seems to be noise. Yet, when printed (at a photo lab), the same pictures come out very sharp and with nice color saturation. I have printed mostly 4x6 but I have also printed a couple of 8x10 and 5x7 with the same good results. Also, when resized on the screen, those artifacts are normally not visible either.

I learned not to worry about it. My advice: don't look at the pictures at 100% magnification. :lol:
Does then 14n force compression It looks like the Kodak I like the most. The picture above did look "painted." I'm used to seeing 6MB or so pics.

Eric
ewitte is offline   Reply With Quote
Old Dec 12, 2003, 8:23 PM   #14
Senior Member
 
Join Date: Jun 2003
Posts: 172
Default

Luisr - You say you have printed at 8x10? How did that come out? From what I recall the 4330 would be 3x Optical Zoom, 3megapixel, yes?

I agree with your idea of just not looking at the picture at 100%, seems the easiest solution and if they print okay then I wont worry about it.

As far as people mentioning the amount of light in the picture and the corresponding aperture size, that shot was taken almost directly into the sun, so while the centre of the shot was well illuminated, the border areas may not have been.. this was probably compounded by the fact that I may not have changed the exposure metering from Centre-spot... am I correct in this? That the picture may have been better with Exposure Metering set to say, Multi-Pattern? Please correct me if I am getting terms and definitions wrong here.. my sig is accurate.. I am a newbie..
PlatinumWeaver is offline   Reply With Quote
Old Dec 12, 2003, 9:03 PM   #15
hst
Senior Member
 
Join Date: Jul 2003
Posts: 182
Default Sun

Most camera manufactures recommend you don't shoot directly at the sun because it can damage a cameras sensor. I looks almost like you are shooting directly at it and it is probably having a difficult time trying to balance the backlight with the forground.

I ran the photo though NeatImage just to see what it would do and the photo looks much cleaner. An 8x10 would probably look good.
hst is offline   Reply With Quote
Old Dec 13, 2003, 12:15 AM   #16
Senior Member
 
Join Date: Jun 2003
Posts: 172
Default

I have got a copy of neatimage or at least the demo and I've tried fiddling around with it, mostly to remove JPEG artifacts..

Are there any tweaks you know of with regards to this kind of inbuilt error correction that you could pass on?

Also, although the camera was pointing straight at the sky, there were a lot of clouds, I thought it would be the amount of light coming in that would hurt the camera rather than UV or anything like that that might not be affected by clouds, am I wrong?

Thanks all, very glad I came back...
PlatinumWeaver is offline   Reply With Quote
Old Dec 13, 2003, 5:45 AM   #17
Senior Member
 
Join Date: Aug 2002
Posts: 2,162
Default

Just a couple of observations. If the file sizes are varying from 250K to 1 Mb, then the camera must be making some pretty hard decisions on criticality of scene detail and how much compression to use. I've only ever seen about 10% variation in file size on my 602. The problem with just looking at scene edges, is JPEG artefacts in my opinion look their worst in large areas of plain colour like sky, which a camera might think is not critical and choose lots of compression.

I was curious about the apparent high shutter speed, even shooting into the light, so I wondered what this camera was doing with ISO speed.

I noticed some black edge countouring on one of the pics. So I wondered what the detail might look like if sharpening could be turned off, and carefully applied afterwards in editing. However, if this 3.1 Mpix camera really is choosing to output a 250Kb file then artefacts post sharpened may look worse. VOX
voxmagna is offline   Reply With Quote
Old Dec 13, 2003, 10:39 AM   #18
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Quote:
Originally Posted by voxmagna
I was curious about the apparent high shutter speed, even shooting into the light, so I wondered what this camera was doing with ISO speed.

I noticed some black edge countouring on one of the pics. So I wondered what the detail might look like if sharpening could be turned off, and carefully applied afterwards in editing. However, if this 3.1 Mpix camera really is choosing to output a 250Kb file then artefacts post sharpened may look worse. VOX
Unfortunately, it appears that this Kodak model does not give the user to ability to change sharpening (just like it gives no control over the amount of JPEG Compression used).

Judging from the EXIF, it was an ISO 100 shot. It's shown as "Exposure Value" versus ISO speed in the EXIF.
JimC is offline   Reply With Quote
Old Dec 13, 2003, 5:32 PM   #19
Senior Member
 
Join Date: Mar 2003
Posts: 438
Default

Quote:
Originally Posted by PlatinumWeaver
Luisr - You say you have printed at 8x10? How did that come out? From what I recall the 4330 would be 3x Optical Zoom, 3megapixel, yes?
Yeap, 3x zoom and 3 MP. The only picture I have printed at 8x10 came out excellent. It was a very good picture to start with, given that it was a night shot and it was the first time I had a shooting session with my (then) brand new camera almost a year ago. I was shooting the Christmas decorations at the town square (see them at http://www.juanadiaz.org/plaza2002 ). The last shot in that URL is the one I printed at 8x10 for framing. Those pictures were also taken at 2 MP because I didn't have a big enough memory card yet at the time and was using the 16 MB internal memory. The 8x10 was printed at one of those Kodak Picture Maker kiosks that has a dye-sublimation printer. The 5x7s were printed at a Fuji Frontier mini lab and were as good or better.

[Edit: I should add that the last picture in the URL was assisted by a slave flash, not just the tiny wimpy little flash that the camera has.]

I am getting ready for this year's pictures tonight as I write this. :lol:
luisr is offline   Reply With Quote
Old Dec 13, 2003, 5:33 PM   #20
Senior Member
 
Join Date: Mar 2003
Posts: 438
Default

Quote:
Originally Posted by voxmagna
Just a couple of observations. If the file sizes are varying from 250K to 1 Mb, then the camera must be making some pretty hard decisions on criticality of scene detail and how much compression to use.
A night shot with lots of nothing but black sky will come out at 200-300 KB in size. A daytime shot with lots of detail will be larger than 1 MB at the same resolution.
luisr is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 12:28 PM.