Casio Exilim EX-Z850 Review
ISO Sensitivity / Noise levels
ISO equivalence on a digital camera is the ability to increase the sensitivity of the sensor. The works by turning up the "volume" (gain) on the sensor's signal amplifiers (remember the sensor is an analogue device). By amplifying the signal you also amplify the noise which becomes more visible at higher ISO's. Many modern cameras also employ noise reduction and / or sharpness reduction at higher sensitivities.
To measure noise levels we take a sequence of images of a GretagMacBeth ColorChecker chart (controlled artificial daylight lighting). The exposure is matched to the ISO (ie. ISO 200, 1/200 sec for consistency of exposure between cameras). The image sequence is run through our own proprietary noise measurement tool (version 1.4 in this review). Click here for more information. (Note that noise values indicated on the graphs here can not be compared to those in other reviews.)
Casio EX-Z850 vs Nikon P3
Unsurprisingly noise is broadly similar at all ISO settings, with Casio's stronger noise reduction at ISO 400 producing slightly lower measurable noise at ISO 400 (to look at the images you'd never know this - especially given how soft the Nikon image is). Back to the Casio, the noise reduction is fairly aggressive, giving ISO 400 images a rather 'watercolor' like effect, though they do remain pretty sharp, and there is still some detail there, meaning if you don't print too large the results are perfectly usable.
Casio EX-Z850 'High sensitivity mode'
As is increasingly common the Z850 offers a high ISO option, though it's only available in a couple of the Best Shot scene modes, and you can't actually choose ISO 800 or 1600 (in High Sensitivity mode the auto ISO simply increases its maximum setting to 1600).
We don't actually know if the EX-Z850 uses pixel binning for its high ISO (as most of the other 8MP cameras with such modes do); I suspect not - the loss of detail is severe, but nowhere near as extreme as seen on cameras such as the Olympus Stylus 800 or Panasonic FZ7 (both of which do use pixel binning).
ISO 800 and 1600 shots are, to put it politely, slightly challenged in the image quality department. There is lots of visible noise, though this is masked to some extent by the huge amount of noise reduction, which produces a rather odd 'motion blur' effect. There is also still plenty of visible noise (particularly chroma noise) in the shadow areas, and the overall result is images that look fairly 'dirty', and - as the studio scene below shows - lacking in detail.
At the end of the day, the question - as with all these 'high sensitivity modes' - we have to ask is this; given it is obvious that current CCD technology can't deliver high sensitivity in such a small sensor is it better to have a mode that allows flash-free photography in very low light, no matter how poor the end result?
Having used several of these types of cameras to capture shots - at parties and outdoors at night - that would have been nigh on impossible without ISO 1600 (where flash couldn't be used, or where subject motion would make even a tripod pointless) I think the answer has to be yes. That said, the way these features are marketed means anyone buying without having seen a review (or sample shot) is going to be very disappointed if they are expecting the results to be useful for anything beyond social snaps intended to be printed small - or viewed on-screen at a reduced magnification.
Studio scene (ISO 1600, high sensitivity mode)
|Studio scene, High Sensitivity BS mode
ISO 1600, 1/10 sec, F3.6
|100% crop||100% crop|
Note that as you cannot manually select ISO 800 or 1600 we had to force the auto ISO (in High Sensitivity BS mode) to choose 1600 by removing the lighting from our studio scene (which is why it looks different to normal).
Luminance noise graph
Casio EX-Z850, Nikon P3, Canon PowerShot S80
Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of luminosity is on the vertical axis.
It comes as no surprise to see that noise levels across these three 8MP cameras are broadly similar, with the main differences reflecting the amount of noise reduction used. The EX-Z850 noise is definitely on the low side for a camera in this class (especially at ISO 400), and as noted above you will see strong noise reduction effects if you print the images too large.
RGB noise graph
Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of each of the red, green and blue channels is on the vertical axis.
Again the noise levels are pretty much around the average for an 8MP camera (all are slightly higher than you'd see from one of the latest 6MP or 7MP models).
|Patrick Finds Inner Peace by ecastellon|
from Your best photo of the week!
|Forks by Kukla|
from Arranged everyday objects
The new iZugar 3.25mm F2.5 super fisheye lens offers an insane 220-degree angle of view. That means it can basically see behind itself... good luck keeping your feet out of the shot.
You'll laugh, you'll cry, you'll remember that time you took a picture of the frozen pizza baking directions.
A Craigslist poster has discovered the worst possible way to photograph a car: taking pictures of pictures displayed on a cracked and scratched up smartphone screen.
With the iPhone X coming out soon, the title probably won't last, but the iPhone 8 Plus is officially the best smartphone camera DxOMark has ever tested, and the iPhone 8 is second.
Kodak's new Facebook Messenger chatbot is trying to bring back the 'Kodak Moment' by digging up your old social media photos and trying to sell you prints and custom coffee mugs.
Affinity Photo for iPad was touted as "the first full blown, truly professional photo editing tool to make its way onto the Apple tablet." This update makes it that much more convenient.
Yashica has released a new teaser video, and this one claims they'll be releasing an "unprecedented camera" in October on Kickstarter. Ready... set... speculate!
Storage solutions company Synology has just released its very first 6-bay NAS tower. Combined with the DX1215 expansion units, it can hold and control up to thirty drives.
We're always expanding our collection of product overview content, and we've just added videos for the Canon EOS 6D Mark II, the EOS Rebel SL2 and EOS M6.
The venerable Canon PowerShot G1 was announced seventeen years ago this week, marking the start of a line of enthusiast-focused compacts that's still alive and kicking.
Super macro photographer Can Tuncer captured these incredible close-ups of a single peacock feather using a special setup and three different microscope lenses.
After successfully crowdfunding the Biotar 75mm F1.5, Oprema Jena is at it again. This time they're bringing back the Biotar 58mm F2: the world's only lens with a 17-blade aperture.
Adobe's move to a subscription model is treating it very well indeed. The company has posted record revenue for the second quarter in a row, hauling in a mind-boggling $1.84 billion.
More details have emerged about the potential sale of Blackstone's 45% stake in iconic camera brand Leica.
Popular mobile editing app Snapseed just got a major update that includes a new interface and 11 new presets for both Android and iOS, as well as adding the Perspective tool to the iOS version.
It might sound like a strange idea, but taking macro photos of boiling water can actually result in some really cool photographs. A good photo experiment for a rainy day.
The database was created to "break with the narrow lens through which history… has been recorded" by equipping those who commission photography with "the resources to discover photographers of color available for assignments.
Lensbaby has released two new optics for their special "optic swap system." The Lensbaby Sweet 80 Optic gives you that trademark sweet spot of focus, while the Creative Bokeh optic gives you 9 different drop in aperture plate options to play with.
TechCrunch has already posted their review of the upcoming iPhone 8 (not yet the iPhone X), and they're calling it "a look into the augmented future of photography."
Affinity Photo is a $50 photo editing software with no subscriptions. That's it – pay for it once and you're done. And we think it's actually pretty darn good.
Instagram is currently testing a major change to the app's profile layout: replacing the 3-photo across grid with a 4-photo grid... and some users are NOT taking the news well.
A report by USSRPhoto is shedding some light on the return of the famed Zenit camera brand. It seems the full-frame mirrorless camera they're working on will be made in part by Leica using components from the Leica SL.
According to a reliable Korean report, Samsung is developing a smartphone sensor that's capable of super slow motion. Translation: Samsung's next batch of Galaxy smartphones may be able to shoot 1,000fps.
This simple photograph of a seahorse and Q-tip has taken the internet by storm. We spoke to photographer Justin Hofman about how it was captured, and what it means to him.
After a massive leak last week, Profoto has officially debuted the Profoto A1: the company's first on-camera flash system that they're calling "the world's smallest studio flash."
"When the first hyperfocal distance charts were designed, someone decided that an acceptably sharp background contained some blur — enough to notice in a medium-sized print [...] After that point, nearly every other hyperfocal chart followed suit."
The Canon EOS Rebel SL2 (also known as the EOS 200D) is the company's impressively compact entry-level DSLR. Packing a 24MP APS-C sensor, DIGIC 7 processor and Dual Pixel AF, it promises a lot of bang for the buck. And while not mind-blowing, it handles most tasks very well.
Correct these four common composition mistakes and your photos will be more balanced, tell a better story, and lead your viewer's eye where you want it to go.
The rugged, compact 360° action camera Kodak unveiled at Photokina in 2016, the Kodak PixPro Orbit 360, is finally available in the United States.
iOS 11 launches tomorrow, and it'll save all of your pictures in a new high efficiency image format called HEIC. Fortunately, there's now a converter that will let you turn those photos back into JPEGs.