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PostPosted: January 9th, 2014, 10:09 am 
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If you've noticed how variable reviews can be from reviewer to reviewer when choosing a camera, PCMag attempts to remove some of the subjectivity and reviewer bias (eg. by using Imatest software to help judge image quality).



Quote:
How We Test

The PCMag photography lab uses a series of tests to objectively rate the image quality and speed of digital cameras. We judge image quality based on sharpness, noise, chromatic aberration, distortion, and dynamic range; and speed tests track the camera's boot-up time, recycle time (the time between shots), and shutter lag. All the results we gather in the lab are then measured against "real-world" shots taken outside of the lab.

In PCMag photography testing, we use the following tools:

•X-Rite ColorChecker
•Imatest
•Shooting-Digital.com Shutter Lag Stopwatch
•Lowel DP
•Spyder3 Elite


http://www.pcmag.com/article2/0,2817,1623933,00.asp


The first slide is here:

http://www.pcmag.com/slideshow_viewer/0 ... o=1,00.asp

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PostPosted: January 9th, 2014, 12:06 pm 
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The sites I use, like Steve's Digicam, dpreview, and CU, are acceptably objective. I can compare specific measurements for cameras within those sites.

Some things still require judgement, but I've found that the reviewers are not just making things up, the way wine experts do in describing wines.

Canoe reviews could sure use more objective measurements, but that would make them so costly to do that we wouldn't see many.


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PostPosted: January 10th, 2014, 9:55 am 
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...I've found that the reviewers are not just making things up, the way wine experts do in describing wines.

Canoe reviews could sure use more objective measurements, but that would make them so costly to do that we wouldn't see many.


An explanation that's been given here in the past when people complain about a canoe's performance, has been... well, you just don't know how to paddle.... wine connaisseurs might say something along the same lines, well, you just don't know how to drink. To which the casual consumer would reply that they don't actually drink, spitting out perfectly good wine is what they do best.

Another thing about fine wine, the more people pay for a bottle, the more likely they are to say they enjoyed it. Maybe confirmation bias could also apply to canoe choice, especially after buying them (all those glowing, yes I'm pleased as punch with my new purchase, buyer's reviews over at paddling.net seems to support this since there are few bad reviews).

The reason I thought PCMag's description of how they test cameras was interesting (I googled it accidentally while checking out Imatest), was during the waterproof pocket camera discussions here during the last year or two, they provided numbers from their lab tests on how sharp a lens was along with the other findings relating to image quality. They'd report a camera providing sharp images after testing while another reviewer would say, nope, not sharp, for the exact same camera.

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PostPosted: January 10th, 2014, 10:04 am 
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There are a number of sites and periodicals that I review when looking for new equipment. There are times when I have reached a saturation point and am overwhelmed, self induced of course. Best thing I have done, even with vehciles, is go to a store and pit them against each other in my own tests. if the store is not willing to allow me to do this, I move on.

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Last edited by Skeeter on January 13th, 2014, 8:52 am, edited 1 time in total.

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PostPosted: January 13th, 2014, 8:32 am 
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So are there any other camera review sites out there that describe exactly how they test cameras so that there's some hard evidence to back up the judgement given besides an individual reviewer simply saying, yes in my opinion it's good, or, no it's not.

So far there doesn't seem to be a great deal of difference between cameras within a class, once you decide which features you want to have.

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PostPosted: January 13th, 2014, 10:56 pm 
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On your earlier comment about lens sharpness, there are tiny differences between successive examples of the same camera, and experienced reviewers sometimes spot and describe them.

I've favored PC Mag since I started reading them back in the early 80s. I'll reserve judgement on their numbers. I always compare across different reviewing sources, and to some extent I can work around individual reviewer slant.


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PostPosted: January 14th, 2014, 1:43 pm 
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Yeah, I reached decisions on gear the same way, I read reviews and descriptions until saturation, then sensing I knew enough, went ahead and bought what seemed to be the best choice available.

And I agree that differences in performance from camera to camera may be tiny, maybe not visible or significant much of the time... as an example, here's a photo of the Little Mississippi river near my home - plenty of detail in there for the camera to resolve (an Olympus TG-820 waterproof pocket camera).

Image

With the unaided eye viewing the actual scene, there's a wooden structure barely visible inside the yellow framed-off portion of the photo, at the edge of the forest and wetlands. It's almost invisible in the wide-angle photo above.

Once the framed-off portion is blown up several times by post processing the same photo, a rectangular duck blind does show up in the fine detail.

Image

So, small differences in sharpness wouldn't have made much of a difference here. The camera is sharp enough for casual snapshots, and there's more detail captured in the photo than what shows up on the monitor, or with the unaided eye at the original scene. But not sharp enough for large prints... I won't be making those with this camera so for my purposes on canoe trips, good enough.

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PostPosted: February 24th, 2014, 12:30 am 
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I've relied mostly on the Canon Elph SD800 IS since 2007. It's only a 7 mp camera. Yet when photos were taken in good light, 8 X 10 prints have been excellent. I'm sure a pro with a magnifying glass could fault them, but no one else sees deficiencies.

I'm now using a new Canon G15 part of the time. Its 12 megapixels do allow more cropping, but also slow storage of each shot, though one doesn't usually notice the delay. I would urge others not to take and store shots at maximum resolution if you are photographing action where you need to take shots quickly, or if you want to avoid using up your storage chip. Having 16 or even 20 megapixels just isn't an advantage for all kinds of shots.

The Canon G15 in its waterproof case is a bit of a handful--- two hands are best. Eric Nyre, who used to post here occasionally, made a very clever foam holder for his Canon SD800, so that it rested on his foam pedestal with its lens safe from sloshing or fogging. There were provisions so that the camera-in-case would not fall out if the canoe capsized.

I've usually carried cameras on my person, but haven't been able to avoid getting the lens sloshed or fogged from time to time.


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PostPosted: February 24th, 2014, 10:18 am 
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Quote:
I've relied mostly on the Canon Elph SD800 IS since 2007. It's only a 7 mp camera. Yet when photos were taken in good light, 8 X 10 prints have been excellent. I'm sure a pro with a magnifying glass could fault them, but no one else sees deficiencies.


It's been written that for most photos, 6MP is good enough and going too far over that is overkill - most won't notice any difference between 6 and 12 MP, unless the image is blown up or large prints are being made.

With compact pocket cameras that have small sensors, image quality may actually decrease with more MPs being packed onto the sensor. Some camera reviewers have advised that if there's a choice between a 12MP and a 16MP pocket camera, choose the 12... the lower megapixels will allow greater light sensitivity, better signal-to-noise, fewer image aberrations and faster shutter speeds and image processing. But the image quality also depends on the image processor chip and how it works to overcome various image quality problems.

Here's a photo taken at 3MP... no visible difference in sharpness or pixelation when compared against photos taken at the usual 12MP (unless the image is blown up considerably).

Image


Quote:
I've usually carried cameras on my person, but haven't been able to avoid getting the lens sloshed or fogged from time to time.


Some pocket cameras have sliding lens covers which stay closed with power off and slide open only when the camera's turned on... this was a feature on the Olympus TG-820 that probably helped to keep water off the lens when the camera was in the canoe somewhere with water splashing around... normally it's in a plastic bag, in a pocket.

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PostPosted: February 24th, 2014, 10:42 am 
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I think lens fogging and moisture on the lens is a bugaboo for all cameras that we carry on canoe trips.

My waterproof fogged up badly when brought into the sun when it was stored near the cold bottom of the canoe.. And of course one errant drop of water can ruin a shot..too bad you don't see what the lens sees before you take the picture.

I am done with sliding lens covers. I have had two that malfunctioned. One opened halfway.. the other not at all when the camera turned on. Of course this happened right after the warranty expired.

A manual lens cap over the lens does help with anti slosh but not with fogging. Motto is keep your camera warm next to you.


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