Previous page Next page

Resolution Chart Comparison (JPEG and Raw)

Images on this page are of our standard resolution chart which provides for measurement of resolution up to 4000 LPH (Lines Per Picture Height). A value of 20 equates to 2000 lines per picture height. For each camera we use the relevant prime lens (the same one we use for all the other tests in a particular review). The chart is shot at a full range of apertures and the sharpest image selected. Studio light, cameras set to aperture priority (optimum aperture selected), image parameters default. Exposure compensation set to deliver approximately 80% luminance in the white areas.

What we want to show here is how well the camera is able to resolve the detail in our standard test chart compared to the theoretical maximum resolution of the sensor, which for the charts we shoot is easy to work out - it's simply the number of vertical pixels (the chart shows the number of single lines per picture height, the theoretical limit is 1 line per pixel). Beyond this limit (which when talking about line pairs is usually referred to as the Nyquist frequency) the sensor cannot faithfully record image detail and aliasing occurs.

This limit is rarely attained, because the majority of sensors are fitted with anti-aliasing filters. Anti-aliasing filters are designed to reduce unpleasant moiré effects, but in doing so, they also reduce resolution (the relative strength and quality of these filters varies from camera to camera). In theory though, a sensor without an AA filter, when coupled with a 'perfect' lens, will deliver resolution equal to its Nyquist limit. Therefore, even though it may be effectively unattainable with normal equipment in normal shooting situations, an understanding of a sensor's theoretical limit provides a useful benchmark for best possible performance. Nyquist is indicated in these crops with a red line.

On this page we're looking at both JPEG and Raw resolution. For a (more) level playing field we convert the latter using Adobe Camera Raw. Because Adobe Camera Raw applies different levels of sharpening to different cameras (this confirmed) we use the following workflow for these conversions:

  • Load Raw file into Adobe Camera Raw (Auto mode disabled)
  • Set Sharpness to 0 (all other settings default)
  • Open file to Photoshop
  • Apply a Unsharp mask tuned to the camera, here 180%, Radius 0.4, Threshold 0
  • Make 100% crops and save the original file at JPEG quality 11 for download
JPEG (4352 x 3264) 2.0MB JPEG (4352 x 3264) 5.3MB

Vertical resolution

JPEG
Raw

Horizontal resolution

JPEG Raw

The Canon G1 X's JPEG engine does a very decent job of resolving the captured image detail, showing distinct lines up to around 2400 l/ph and with relatively few artifacts beyond that point (there is a small amount of moire at higher frequencies). This suggests the camera is using a light AA-filter in front of the sensor.

Processing with Adobe Camera Raw and then applying customized sharpening reveals some additional detail but you also get a lot of false color artifacts appearing at higher frequencies. That said, away from the world of test charts, in real-life scenarios, this becomes a non-issue. All in all this is about the performance you'd expect to see from a 14MP camera.

Previous page Next page
Our favorite products. Free 2 day shipping.
Support this site, buy from dpreview GearShop.
Canon PowerShot G1 X

Comments

Total comments: 9
rugosa
By rugosa (2 months ago)

I bought a G1X 2 weeks ago from a person that bought it for his wife for Christmas. She found it too much camera for her needs and so I bought it with about 10 shots total for $400. I usually shoot with a Nikon D300 and the Nikon higher priced lenses. For underwater and a light carry around I had a G10 for 5 years. After 2 weeks of shooting I must say that I'm amazed by the IQ of the photos this camera puts out. Low light shots up to ISO 1600 are allot better than my D300. It's not a perfect camera but then non of them are. Ordered a Canon 500D close up lens for it after seeing how well that worked on Marco Nero's photos with the G1X on www.pbase.com . This camera also shoots some very good underwater photos from examples I have seen on the internet so I picked up Canon's case on sale for my trips south. All told I think that although this camera is not for everyone most owners give it at least an 8/10. www.witnesstobeauty.com has another good review, great landscape photos

Comment edited 51 seconds after posting
0 upvotes
Gunzorro
By Gunzorro (2 months ago)

I've been wanting this camera since it was announced. I'm primarily a DSLR shooter, and FF at that. I also have owned a G6 and currently G10 and S110. So, I'm pretty familiar with where this camera fits in and what a step it is for Canon to take.
I just bought a used version at a very nice price so will be trying it out in the near future.
I would have rated the camera a little higher, based on my past experience with Canon and reports I've read from reviews and owners. Particularly, Optics and Performance would have got a couple ticks up in my estimation. I think a 79 or 80 would have been appropriate -- being practically in a category of its own: attached zoom, large sensor, compact camera.
It won't be a camera for everyone, true. But if you want better IQ than P&S and use it as a second camera to your DSLR for quick grab shots and take-anywhere convenience, you should be well served! :)

0 upvotes
jan snks
By jan snks (5 months ago)

Image quality G1X, dpreview reports "excellent image quality across the ISO range without nasty surprises".
I would like to refer to the www.imaging-resourcing.com review of this camera. They reported a nasty Light Leakage phenomenon at higher ISO settings and short shutter times. This defect seems to be confirmed by Canon.
Would anybody comment on this ?

0 upvotes
millhoud
By millhoud (6 months ago)

I've noticed that the g1x took this studio shot at f7.1 , while other "enthusiast" compacts (g15 or p7700...) at f4.5. Could somebody explain me why's that? It would be nice to know the shutter speed too. Thanks

0 upvotes
Richard Butler
By Richard Butler (6 months ago)

It's to offer enough depth-of-field (it's a 3D target).

This has a sensor much bigger than the others, so needs to be stopped-down further in order to provide enough depth-of-field.

0 upvotes
millhoud
By millhoud (6 months ago)

Please sorry my ignorance, but to achieve this it has to use a slower shutter speed too or, thanks to the higher light-catching capabilities of the bigger sensor the g1x uses comparable shutter speeds as, say, the g15 or p7700 , with a smaller aperture?

0 upvotes
lem12
By lem12 (7 months ago)

If Canon increases DR able to at least match T2i and updates its Panorama mode (similar to the Sony's would be great), this would be true compact I'm looking for. I'll buy it no doubts!

0 upvotes
Wildbegonia
By Wildbegonia (7 months ago)

Almost but not there yet.

3 upvotes
Ponderer
By Ponderer (8 months ago)

G1x Cannons almost camera
Almost an APS-C sensor, Almost a good EVF, Almost enough lens magnification, Almost small enough. A good first try for a company that just started designing cameras.

9 upvotes
Total comments: 9