Showing posts with label camera. Show all posts
Showing posts with label camera. Show all posts

Tuesday, July 3, 2007

N95 camera - scene settings

I've been playing with the camera settings during the last couple of days. There's something very strange in the way some of the scenes work.
N95 allows you to choose between eight different scenes:
  • Auto
  • User defined
  • Close-up
  • Portrait
  • Landscape
  • Sports
  • Night
  • Night portrait
I took a photo using landscape scene. When I opened the photo in PhotoShop it was not what I expected. Most of the image was out of focus and it seemed to have a very small depth of field (DOF). Landscape scene setting is normally used to give you a large depth of field. The area within the depth of field appears sharp while the areas in front of and beyond the depth of field appear blurry. Small depth of field is certainly not something that you would expect when using landscape scene.
I thought I'd experiment a bit with the scene settings and took photos using Auto, Portrait and Landscape scene. I then compared them in Photoshop to see if there really was something strange. Below is a set of three images with different scene settings: Auto, Portrait and Landscape (from top to bottom).




Most of the time I've been using Auto scene when taking photos with N95 and haven't noticed anything strange. The first image, taken with Auto setting, seems to be as expected.
The second image is taken using Portrait setting. What I'd expect from a Portrait setting is a small depth of field. It usually used when taking photos of a person and you want the person to appear in focus while anything in front or behind the person are blurred. The Portrait photo taken using N95 is completely opposite. It seems sharp all the way from near to far. A closer look tells that a lot of post-processing has been done to sharpen the image.
The third photo was taken using landscape scene. First thing I noticed when taking a photo in landscape scene was that the lens didn't try to focus at all. As you can see from the photo, it has very small depth of field while objects near and far are blurred. Not really what you'd expect in a Landscape mode.
Landscape and Portrait scenes seem to produce unexpected results. It almost seems like the Portrait and Landscape modes should be switched. I thought I had accidentally changed the scene modes in wrong order but when I repeated the experiment (several times) I always got the same result.

Saturday, June 16, 2007

N95 camera review (part 1)

It's very handy to have a camera in a cell phone. The 5 megapixel camera of N95 takes decent photos but how does it compare to digital cameras. It would be unfair to compare it to SLRs with expensive lenses. Therefore, I decided to compare it to a pocket size digital camera with the same 5 megapixel resolution. Samsung L55W is a small digital camera with a wide angle lens and a 4.8x optical zoom. Let's see how the N95 camera compares to L55W.
The two photos below were taken at the same location. I tried to get the optical zoom to match the zoom level of N95 but didn't get it quite right but it's close enough. The first image is taken with N95 and the second one is taken with L55W. These photos are used as an example to show how the Nokia N95 performs against the Samsung L55W. These images were taken under good lighting conditions. The differences between these two cameras become even clearer when lighting conditions become worse.


The first big difference is the file size. Both cameras were set to automatic exposure and best image quality and both have 5 megapixels. While the file size of the image taken with N95 is only about 1 MB, the image taken with L55W is almost 2.4 MB. That's a huge difference hinting that the image taken with L55W is likely to contain more detail. You can click on the images to see them in full resolution.
There's also a quite a big difference in the overall tone of the image. The N95 seems to produce warmer tones. And even though the software update improved it a lot, the N95 still suffers a bit from producing images that are slightly red tinted.
Next, let's take a look at how well these two cameras capture the small details. Below are two examples with the N95 image on the left and the L55W image on the right. First is a detail from the lower left hand corner of the original image where you can see some leaves of the tree. The second image is a detail of the plant and water on the right. A big difference in both of these details. The N95 doesn't really preserve the details very well. The leaves are blurred and in many places it looks like it's been painted using water colors. The L55W captures the details much better.




The last example is a detail of the sky. Again the N95 image on the left and the L55W image on the right. Ideally the sky should be very uniform color with a smooth gradient. The N95 image seems to have a lot more noise or at least the noise is much more visible. By looking at the histograms of the two images, it becomes clear the there is more noise in the image on the left, i.e. the image taken with the N95. The reason for this is also obvious. The small lens of a cell phone camera simply can't collect the same amount of light as a bigger lens of a real digital camera.
A more careful analysis of the image reveals that the N95 image has more noise than the L55 image on all color components (red, green, blue). The red component of the N95 image has the most noise. Maybe this is what makes the image appear red tinted? If you look at the image, it seems like it's filled with red tinted spots.


As a conclusion it can be said that the N95 camera doesn't produce the same quality as a normal pocket sized digital camera. The L55W is a clear winner of this comparison. The N95 doesn't capture all the details, produces more noisy images and suffers from red tinting. The noise reduction algorithm makes some parts of the image look like water color painting. Having said that, these become a problem only if you look at the full 5 megapixel resolution or print in large format. The images taken with N95 are good for printing in the standard 10 cm x 15 cm (4''x6'') format. And it's still the best digital camera I've ever had in a cell phone.

Monday, May 28, 2007

Camera - introduction

I'm preparing a full review of the N95 camera functionality and image quality. Here's just some first impressions.
The N95 has a main camera with a 5 Megapixel sensor and Carl Zeiss Optics. The main camera is capable of capturing stills as well as videos. There's also a second, lower resolution camera for video calls. So in paper it looks really good. How does it perform in reality?
Below is an image taken with N95 using the best image quality settings. Click on the image to view a slightly larger version. The image has not been processed in any way. It has just been scaled down to reduce resolution. It was a clear and sunny day so the lighting conditions were good. If you don't look at the image at full resolution (100% magnification) it looks good. The color balance is good (with the latest firmware).
If you look at 100% magnification, then you start seeing the true image quality. The second image is a detail taken from the original 5 Megapixel image. There you can see the biggest problem with the N95 camera. It seems like the noise reduction algorithm is too aggressive. It blurs the details too much (look at the leaves). It would be interesting to know how noisy the original image is. It would be great to be able to control the amount of noise reduction.
Other than that, the first impression of the image quality is good. Not bad for a cell phone.