Go Back   Steve's Digicams Forums > Digicam Help > Newbie Help

Reply
 
Thread Tools Search this Thread
Old Jan 31, 2004, 10:07 AM   #1
Junior Member
 
Join Date: Jan 2004
Posts: 2
Default fringing problems

I recently purchased a Kodak EasyShare DX4530. Kodak claims that photos from this camera can be enlarged up to 20 x 30, but even at a slightly smaller enlargement of 8-1/2 x 10, I didn't find the overall quality of the printouts to be very sharp. In fact, there was a terrible purple fringe on tree foliage, roofline, etc. Evidently this is a VERY common problem in digital photography that I had never heard of. How do the experts on this forum deal with this outline problem. I can't believe that this is acceptable to any photo enthusiast--yet these digital cameras have been selling like hotcakes for some time now. By the way, I returned the Kodak back to the retailer with no problem and am considering either a Canon 5 MP PowerShot G5 or a 5 MP Minolta DiMAGE G500.

Help! How do you deal with this fringing problem? Thanks.
Branigan is offline   Reply With Quote
Sponsored Links
Old Jan 31, 2004, 10:40 AM   #2
Senior Member
 
Join Date: Jan 2004
Posts: 824
Default

It's a good thing you could return the camera :!: .

Chromatic aberration, aka “purple fringing” is a side-effect of all lenses, and the effect particularly increases with zoom power, though it’s more prevalent on some lenses than others. That’s why you should buy your camera from a manufacturer known for lens quality. If you check around the web for reviews of the DX4530, you’ll find that most reviews complain of the purple fringing. According to the ZDNet review, “The DX4530 displays unusually frequent chromatic aberration, which manifests itself as thick purple fringing.” Comments are similar on other reviews. Do a Google search with keywords “chromatic aberration” and “DX4530”, and see what you find. Some fringing can be cleaned up manually in the digital darkroom, but you’re probably better off starting out with a camera with a good lens. In that sense, my choice would be Nikon, Olympus, Canon or Fuji.
Norm in Fujino is offline   Reply With Quote
Old Jan 31, 2004, 10:40 AM   #3
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Actually, it's not only a common problem with Digital Cameras, but it's a common problem with film cameras, too.

It's just that users rarely enlarge prints enough to notice it.

With a Digital Camera, some of the problem comes from the CCD, too.

Basically, each photosite has a microlens over it, and these can also contribute to the problem as light is refracting into adjacent pixels. CCD blooming is also a contributing factor (where charges overflow to adjacent pixels in overexposed areas).

You'll normally see the problem in high contrast areas of a photo that are slightly overexposed (trees against a white sky, etc.).

Some cameras have much higher quality lenses than others, and can eliminate the problem in most situations.

Here is a thread on reducing the appearance of Chromatic Aberrations in your photos:

http://www.stevesforums.com/phpBB2/v...?p=93032#93032

As far as the your purchasng the Canon G5, it's one of the worst offenders (especially at wide apertures).

Basically, Canon decided to stick a higher resolution sensor (with smaller photosites for each pixel) into a camera with the same lens as the older 4MP G3. The lens quality is good, but is really not up to the task of dealing with the higher resolution sensor. It's Chromatic Aberration (Purple Fringing) is worse than most of it's competitors.

I'm not sure what your budget is. However, the Minolta DiMAGE A1 (or DiMAGE 7Hi) cameras have the least CA (purple fringing) of any consumer digital cameras that I'm aware of (in my opinion, based on reviewing lots of photos).

They use an APO (apochromatic) zoom lens, including 2 AD (anomalous dispersion) glass elements to suppress chromatic aberrations. IMO, it does the best job out of all of the available models as far as fringing is concerned.

As far as the Minolta DiMAGE G500, I own the Konica version of this camera (Konica KD-510z). They are identical. IMO, it's an extremely high quality camera, and it's image quality is nothing less than outstanding. I would not trade it for any other subcompact camera made.

However, it's not totally immune to CA. In extremely high contrast situations, you do get some CA on occassion. But, it rarely impacts the photos I take. It's has lower CA than any model I've owned in the past, but it's not immune to it in all situations.

The Minolta DiMAGE G500 is actually the Konica Revio KD-510z. Basically, Konica-Minolta is marketing this model under the Konica label in Asia and Europe, and under the Minolta label in the U.S.

This is my 7th Digital Camera, and I am extremely impressed with it's images. It's metering accuracy, color accuracy, etc., is superb. It's photos require the least post processing of any camera I've owned in the past (with the exception of redeye).

Unfortunately, the closer the flash is to a camera's lens, the greater the potential for redeye. So, if you purchase a subcompact model, be prepared to fix redeye in flash photos. That's just the way it is! However, it is very easy to fix with software (much easier than fixing CA).

See the 24-Jan-2004 19:11 forum entry
underneath the photos at http://www.pbase.com/jcockfield/konica_kd510z

You'll see tips on using the camera and how to correct redeye in flash photos.

You'll also see links to my user review of this model in the text above the photos (where I go into great detail on the features available, etc.).

Let me know if you have any questions about it. I've owned this model since mid-July (about two weeks after it started shipping in Japan). I didn't want to wait until it started shipping in the U.S., so I located and purchased a Japanese model. I was that impressed with it's photos!

However, again, the Minolta DiMAGE 7HI, and A1 have the highest quality lenses IMO. But, I think my little Konica is capable of better photos (image processing algorithms, metering accuracy, etc.). Of course, my opinion is biased (since I really like my Konica).
JimC is offline   Reply With Quote
Old Jan 31, 2004, 10:45 AM   #4
Senior Member
 
ohenry's Avatar
 
Join Date: Dec 2003
Posts: 1,676
Default

I'm certainly no expert on the causes of this but the purple fringing you're seeing is basically a chromatic abberation. Do you see it on all your images or just high contrast images at wider angles? From what I understand, it is a more common problem with cameras in the 2-3 megapixel range. I think the DX4530 is a 5 mpix??? So, guess that blows a hole in that theory

Regardless, about the only thing you can do (short of getting a different camera) is to make corrections in Photoshop or one of the other digital imaging programs.
ohenry is offline   Reply With Quote
Old Jan 31, 2004, 4:59 PM   #5
Senior Member
 
Join Date: Aug 2002
Posts: 2,162
Default

From some research I did, there were only 2 manufacturers offering lens systems like JimC mentions - they were Minolta and Nikon. However life and cameras are always a compromise. I found a good lens/ccd option for CA didn't always deliver the highest sensitivity (Which JimC touched on). It seems difficult to get both in the cheaper compacts. Sensitivity has to be the lead criteria for a lot of shooting situations and affects: Auto focusing, flash power,flash range, depth of field, low noise even getting a pic at all sometimes. VOX
voxmagna is offline   Reply With Quote
Old Feb 1, 2004, 7:50 PM   #6
Senior Member
 
Join Date: Mar 2003
Posts: 438
Default

I have a Kodak DX4330 which is basically the same camera but with a 3.1 MP sensor. I see the same purple fringing in high contrast pictures but it doesn't look like chromatic aberration to me but rather caused by the CCD. It is most apparent in night time pictures with bright white lights in them
luisr is offline   Reply With Quote
Old Feb 2, 2004, 8:29 AM   #7
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Quote:
Originally Posted by luisr
I have a Kodak DX4330 which is basically the same camera but with a 3.1 MP sensor. I see the same purple fringing in high contrast pictures but it doesn't look like chromatic aberration to me but rather caused by the CCD. It is most apparent in night time pictures with bright white lights in them
Kodak makes their own CCD's for most of their cameras. I have noticed that their models due seem more prone to CA. It's probably a combination of the lens and sensor (a CCD has microlenses over each photosite to help amplify the light). So, these microlenses can help magnify any CA, as the light is refracted by them.

Also, some of it is blooming, where charges can overflow from one pixel to another in overexposed areas.

Hopefully, manufacturers will start to make improvements in noise, dynamic range, blooming, etc., rather than just keep increasing megapixel count.
JimC is offline   Reply With Quote
Old Feb 2, 2004, 9:30 AM   #8
Junior Member
 
Join Date: Jan 2004
Posts: 2
Default

Thank you all so much for your very kind and KNOWLEDGEABLE responses. The web sites and other guidance you have recommended simply confirmed what I had started to suspect - - digital cameras have a long way to go developmentally before I'll be satisfied with any that would be even remotely within my price range and meet my expectations. I'll just do a little more studying with regard to 35mm and perhaps look into purchasing an SLR camera. I'm not even sure what the cost will be but at least I think my expectations would be met. By the way, my first 35mm was a Konica and it was a wonderful camera. I got it at least 20 years ago and it still makes better prints than the Olympus I bought a couple of years ago (thought: the newer the better - - wrong).

Thanks a million. You've all saved me from making a potentially costly purchasing mistake. I'll still be coming to this site, though, if only for the great overall advice and just nice folks.

Sue Branigan
Branigan is offline   Reply With Quote
Old Feb 2, 2004, 10:53 AM   #9
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Quote:
Originally Posted by Branigan
By the way, my first 35mm was a Konica and it was a wonderful camera. I got it at least 20 years ago and it still makes better prints than the Olympus I bought a couple of years ago (thought: the newer the better - - wrong).
If you decide to try the Konica KD-510z (a.k.a., Minolta G500), just buy it from a vendor with a no restocking fee policy.

I think you'd like it. Even some of the functions (like AE Lock and AF lock), work the same as they do on some of the Konica Film Cameras. IMO, Konica's experience in this area really shows in the photos from their Digital Camera's, too.

BTW, it's got far less CA than the Nikons I've owned (Coolpix 950, 990). It rarely appears in any photos, and even then, it's minimal.

You can see photos from mine at http://www.pbase.com/jcockfield/konica_kd510z

You can find the Minolta G500 (which is a Konica engineered camera) for a little over $300.00 now. It's a terrific bargain IMO, with photos having a "film like" quality to them.

Good Luck finding a camera to meet your needs!
JimC 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 7:55 PM.