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Old Aug 4, 2004, 4:35 AM   #1
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I have just bought the Pentax S4I.

Prior to my purchase I borrowed a S4 and all my test shots came out GREAT. I was expecting the same quality if not better from my S4I !

However all my images taken with the new camera are highly pixelated ! Surely this is not what to expect from a 4mp camera?

I upgraded from a rather old 2mp Nikon Coolpix and its quality is much better than the quality of my new pentax !

I am using the AE mode and am wondering if my camera might be one of the "faulty" ones mentioned on these pages ? Also is there any setting i accidently might have swiched on which can cause pixelation and image distortion ?

Have a look at the picture below. See her face ? This is not how it is supposed to look (when it comes to picture quality)

I bought the camera abroad so I cant take it back to the shop. Maybe send it back to pentax ?

All your suggestions are highly appriciated !

Ulrik
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Old Aug 4, 2004, 6:50 AM   #2
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Hi Ulrik,

From what I see, your cam is OK. The picture is not, you're right. You probably used the cam with automatic settings only. I suppose you did not use the flash which would have brightened the face. This way the face is in the shadow and only lightened through the redfabric of the umbrella what makes it appear reddish.

The next time you make a picture of a person or object in the shadow, add the flash with the button. For persons you should chose the flash modewith red eye suppression.

However, this picture is not lost. You can correct the missing flash with a computer program such as Photoshop. Try it out!

See also the thread http://www.stevesforums.com/forums/v...mp;forum_id=24and learn how to handle the camera. I know from my own experience that it takes some time to understand all the settings and their interactive behaviour.

I am sure you got a great camera!

cheers.... Mark
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Old Aug 4, 2004, 9:58 AM   #3
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Thank you for your reply.

I see your point about fill in flash. However almost every single picture i take comes out this way (and in all conditions) Surely this should not be the case !

It is difficult to see on the picture I posted in my thread as it has been sized down, but the loss in quality is almost disturbing... Even when I use the flash these pixelated areas occurs...

I know the camera has a lot of settings to play around with, and these settings are all bound to improve the picture quality. Iam just disapointed with the outcome of the AE setting !

I am almost certain that something must be wrong !

Again thank you for your help !

Ulrik
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Old Aug 4, 2004, 1:07 PM   #4
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Hi Ulrik,
You are right! I can now see the picture noise on original large size pictures. When I analyse the Exif data of your pics I notice, that your shutter speed is never faster than 1/100 sec. and your ISO does not come down to 50 even for outdoor pictures in good weather. This is definitely wrong!
Load Exif-o-Matic or EasyExif from here http://www.versiontracker.com/php/se...&action=search and see for yourself.
Make some more tests using the P-Modus (not the green mode) and just add the button settings" flash"/"infinite" a.s.o. when needed. Make sure not holding the cam on the sensors on the front side when taking pictures. If that still does not help, there is a technical problem with the camera. You should then ask the seller to deliver an international warranty certificate and with that you will be able to have it repaired at your nearest pentax site.
Send me a mail on gilmark(at)fastmail.fm and I'll send you the comparison data with some pictures of mine.
Regards Mark
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Old Aug 4, 2004, 1:12 PM   #5
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My guess is that you took the images on the borrowed S4 on a brighter day. When you zoom you lower the light to the sensor. To compensate so you have enough shutter speed to handhold the shot the camera increases the ISO. That gives a lot of noise.

On a dingy day set the ISO no higher than 100 – preferably 50, shoot at wide angle and use fill flash. If you set the ISO at 100 and can't handhold for things outside flash range without motion blur you don't have enough light. Either don't take the picture or accept the high noise.

There isn't anything wrong with your camera. There isn't a tiny camera that will do better. If you want to shoot available light in the conditions those shots were taken in get something with a f1.8-f2 lens or stabilization.
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Old Aug 4, 2004, 11:16 PM   #6
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The main problem I see with your photos is noise.

Keep in mind that the sensor in your camera is even smaller than the 1/2" sensor you'll find in the old 2MP Nikons. Also, there are 4 Million photosites packed into it. The smaller the photosites, the less light they can gather, so more amplification of their signal is needed to get the same ISO sensitivity you'd have with a camera with larger photosites. This amplification increases noise levels.

It's the price you must pay to get a high resolution sensor in a tiny package. In good light and at lower ISO speeds, they're great. But, in lower light and/or higher ISO speeds, noise can "rear it's ugly head".

To reduce noise, as Slipe and others have mentioned, shootat the lowestISO speeds possible without getting motion blur. Also, make sure your subjects are properly exposed. Noise isworse in underexposed areas of a photo. That's why it's a good idea to use fill flash with some subjects outdoors in poor light -- like your "gloomy day" photos(or if they are backlit and in shadows, so you properly expose them). Light is a Digital Camera's best friend.

Also, keep in mind that when viewing a 4MP image on screen, it's much larger than you're ever going to print at. That's why you noise blend in at typical viewing sizes.

You can get tools to reducenoise if very large print sizes are needed. Here are some good ones:

Neat Image: http://www.neatimage.com

Noise Ninja: http://www.picturecode.com

Noiseware: http://www.imagenomic.com/

Note that Noiseware is a free product. It does have some limitations (for example, it strips out the EXIF information, which contains information about the camera settings used). However, it seems to do a pretty good job with noise.


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