White Balance

Once more a HP's white balance algorithms prove to be considerably better than the competition. Indeed the 935's Auto white balance delivered almost perfect balance under a full variety of light. You would rarely need to engage the pre-programmed white balance settings (perhaps for mixed light situations). Manual white balance of course was perfect and reliable. Kudos to HP for having the best white balance we've seen so far.

Outdoors, Auto	Outdoors, Cloudy (or Sunny)	Outdoors, Manual
Incandescent, Auto	Incandescent, Incandescent	Incandescent, Manual
Fluorescent, Auto	Fluorescent, Fluorescent	Fluorescent, Manual

Macro Focus

I really think it's time that an industry organization such as CIPA stepped up and placed some kind of standard on using the word 'Macro'. The HP's 'Macro' focus mode can not in any way be regarded as producing macro performance akin to that available from 35 mm macro lenses, rather it allows a slightly closer focus distance and that's about all. The macro tests below are using our new macro focus test chart and measurement system; each line on the grid is 10 mm, taken at shortest subject distance in macro mode.

Wide angle - 134 mm x 100 mm coverage 19 px/mm (483 px/in) Distortion: Average Corner softness: Average	Telephoto - 132 mm x 98 mm coverage 20 px/mm (508 px/in) Distortion: None Corner softness: Low

Flash Performance

HP quote the 935's flash range as 2.8 m (8.2 ft) at wide angle and 1.3 m (4.3 ft) at telephoto (both at ISO 100). Our experience of flash photography with the 935 was very positive, the camera appears to meter flash power very well, copes with white balance (no color cast) and probably utilizes HP's dynamic tone curve to ensure full use of the output file's dynamic range (a full range of brightness from black to white).

Skin tone - Natural color, no blue cast, very good exposure with good flash power	Color patches - Very good color balance, no color cast, very good exposure

Night exposures

The 935 doesn't have a dedicated night exposure mode, however in aperture priority mode the camera allow shutter speeds as slow as 8 seconds. In our basic test I couldn't get the 935 to focus on the distant lights and had to put the camera in Infinity focus lock. As you can see from the samples below with Infinity focus you need to stop the aperture down to the smaller setting (as the 935 only has two apertures). Results were usable without any visible 'hot pixels' but with quite a bit of residual 'grain noise'.

Aperture Priority: ISO 100, F2.6, 2 sec
Manual exposure: ISO 100, F5.0, 8 sec

Barrel and Pincushion Distortion

The 935's lens exhibited acceptable levels of barrel distortion at wide angle and no measurable pincushion distortion at telephoto. This is a good performance for a compact extending digital camera lens.

Barrel Distortion, 1.0% @ wide angle	Pincushion Distortion, 0% @ telephoto

Vignetting / Light fall off

Our vignetting / light fall off test is very simple, a shot of a blank wall from two meters away, vignetting will always be most visible at wide angle and maximum aperture and will start to disappear at smaller apertures and/or further zoom. As you can see there is some slight light fall off (lens shading) in the bottom corners of the frame, however this is considered relatively good for such a compact lens system.

Slight corner vignetting visible at wide angle and maximum aperture (F2.6)	No noticeable vignetting at telephoto (F4.6)

Purple Fringing (Chromatic Aberrations)

As we have seen of other digital cameras using this 1/1.8" type five megapixel sensor the HP 935 does exhibit some chromatic aberrations however it does appear as though either the lens or image processing pipeline are managing to keep CA under control. We struggled to find a typical 'every day shot' which had noticeable CA, and even this wasn't particularly objectionable or difficult to fix.

Fringing hardly visible in an 'every day shot'	Our standard chromatic aberration test shot

Overall Image Quality / Specific Issues

HP continue to improve, the 935 delivers detailed images with good tone and color. Resolution is good and images don't appear over-sharpened or over-processed They have clearly addressed my concerns with demosaic artifacts which were clearly visible on the 850. HP appear to have pushed color response a little further towards 'Disney color' with vivid well saturated color that 'leaps' out of the image (if you don't like this you can of course tone it down, although only by one level). One thing that really did stand out with the 935 (as well as its excellent auto white balance) was the camera's intelligent use of dynamic range and HP's dynamic tone curves.

Making full use of dynamic range

The 935 always makes full use of the dynamic range of the image with almost every image having a full histogram from black to white, this is a hint at the camera's dynamic tone curve system. It appears to use a combination metering information and captured brightness levels to apply a tone curve which maintains as much highlight detail as possible while not darkening mid-tones or shadow (or affecting color saturation). You always seem to get more 'sky' with the 935 than other five megapixel digital cameras. The two examples below show how the 935 managed to maintain sky color (and some detail) while still delivering good mid-tone and shadow detail.