Nokia N8 HDR Photo Camera Review

Within my previous Camera Pro review I mentioned HDR Photo Camera as the alternative option for taking High Dynamic Range images on a Nokia Symbian^3 device, or more specifically the Nokia N8.

The main difference you will see between HDR Photo Camera and Camera Pro is the later is an all encompassing camera expansion app, the prior focuses specifically on HDRI (High Dynamic Range Imagery).

This is by no means a bad thing, although when we look at the vast functional range of Camera Pro with a price tag of £3 and compare it with the HDR functionality of HDR Photo Camera with it’s price tag of £8 the latter needs to be exceptional.

When it comes to the initial “Bracketing” functionality required for HDRI this is shared between both apps, providing 3-off bracketed images with user modifiable ISO settings. Whereas Camera Pro offers +/-2 stop range for each of the three images, adjustable in 1/3 stop increments, HDR Photo Camera offers +/-3 stop range, adjustable in 0.5 stop increments. In this comparison we believe that HDR Photo Camera wins as the range extension provides extra range to the final image.

Application Walkthrough

The user interface in HDR Photo Camera is very user friendly with a polished appearance with the following main screen functionality:

  • Settings Menus (Cog symbol, bottom left)
  • Flash on/off toggle (lightning symbol, top right)
  • Image Fuse on/off toggle (images symbol, top right)
  • Camera button (camera symbol, bottom, middle)

After accessing the we were presented with:

  • Exposure levels – This menu provides access to the ISO image capture settings for each of the three bracketed images used to generate the final HDR image.
  • Advanced settings – This menu is further split into three sub-menus:
    • Fuse settings – This sub-menu provides access to Contrast, Saturation and Exposure settings.
    • User Interface – This sub-menu provides “Fuse Process” and “Flash” (default) on/off toggles along with a tick box for toggling a two second countdown on and off.
    • Advanced – This sub-menu provides a three level “Bracketing Speed” selection (Quick, Medium, Slow).
  • Fuse Images – This opens a viewer for images captured with HDR Photo Camera and an offline image fusing option.
  • Image quality – This provides access access to Image resolutions selection, with 5 levels of image quality. Anything above Medium resolution with stop the integrated on device fusing process working due to memory requirements. These images can still be taken, but the fusing process will need to be completed on a PC using the developers, soon to be released, PC fusing app. Also on this screen is the option for low or high fuse resolution, which affects the image resolution of the final fused image.
  • Go to photos – This is quite self explanatory providing fast access to the camera’s default photo gallery app.
  • Help – This provides access to the short on device help / user guide.
  • About product – This is also quite self explanatory, providing the user with version number information.
  • More applications – This points to the developer’s (Intellsys) OVI Store page.

Application Usage

Now that I’ve explained what the app can do, lets move on to how and why.

The first this to note when taking bracketed shots is to keep the device as still as possible as the software needs to overlap the 3 images after capture to provide the final image. In the same sense you need to choose an target containing minimal movement. One option is to use a mobile phone tripod ,one of which is available from Mobile Fun for c.£15.

If you are in low light you can enable the camera flash, which will activate on the last image of the bracketed set.

A mentioned above the ”Fusing Process” can be enabled/disabled, but will only work on device if the image is medium quality or below as the image processing undertaken during the “Fusing Process”  requires a large degree of C: drive memory. This image quality should suffice in most cases, but if you are after higher resolution HDR images you will need to fuse using a PC app instead.

A useful tip from the developer is that:

When noticing large or intense grey areas in the fused HDR image, reducing the exposure difference between the over exposed frame and the under exposed one will usually help obtaining better results.

Focus

The on screen camera button acts as a full press of the hard camera button automatically focusing when tapped. You can manually focus prior to starting the bracketed shots by partially depressing the hard camera button until the green rectangle is displayed in the centre of the viewfinder window as with the default camera app.

Exposure levels

On the “Exposure Levels” screen you can adjust exposure levels for each of the 3-off bracketed images for future image captures. An on-screen preview is provided to aid in the user select the best settings for their desired shot.

The default settings are:

  • Image 1: +2.5 Stops
  • Image 2: 0 Stops
  • Image 3: –2.5 Stops

For the best results it is best to over expose the first image, such that the dark areas in the scene are visible and under expose the last image, such that there is no glow on the bright areas. Too much over or under exposure can cause poor image alignment or artefacts (dark-bright gradients) during the fusing process. If this occurs use of a tripod and modification of the  fuse parameters may be necessary help counter the issue.

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Fuse settings

The default settings for the “Fuse Settings” are:

  • Contrast [0-10]: 1
  • Saturation [0-10]: 1
  • Exposedness (Exposure) [0-10]: 5

Setting any of the above as “0” results in it being ignored during the fuse process. It can be seen from the above, default, settings that “Exposure” is prioritised over “Contrast” and “Saturation”.

Advanced settings

Bracketing speed can be modified, although this is not advised for novice users, with the default “Medium” setting being adequate for almost all situations. “Quick” can be selected for very bright scenes with slow moving objects (e.g.: clouds), reducing ghost effects, whereas “Slow” can be selected for dark scenes.

Although it is possible to use “Slow” in some circumstances, it should be noted that very dark scenes cannot be over exposed with flash usage being the only solution. This will obvious affect the final captured HDR image.

Fuse Images

A nice little feature is that images can be fused multiple times with different parameters by pressing fuse button multiple times, for already fused frames, will result in multiple versions for the same HDR file (e.g.: Img251HDR.jpg, Img251HDR(1).jpg, Img251HDR(2).jpg …).

Captured Images

 

Fused Image

 

Conclusion

After using this app for a while I have noticed that a processing error occurs when fusing images of medium quality with high fuse resolution, even with 170Mb free C: drive memory. This is believed to be an issue with the current public Qt library which does not occur with Qt 4.7 developer’s library files and, as a result, will be corrected when Qt 4.7 releases publicly.

The final decision for purchasing or not purchasing HDR Photo Camera (£8) comes down to how often you might wish to take and process HDR images on you Nokia device as if you are prepared to wait, you can use Camera Pro (£3) and post process on a PC.

That said HDR Photo Camera is a very clever app achieving something, in the fuse process,  that no other Symbian app can do. For me this alone justifies it’s installation on my N8.

A couple of improvements, expansions we would like to see in a future release is the ability to choose the number of shots to be bracketed (1, 3 or 5). Five is described as the optimum number of images required for a HDR image and using a single shot to create a HDR image would provide the user with a quick single shot processing option. The post processing would generate a number of ISO modified versions of the original image for fusing.