Pentax K-3 Review
Low-Light High-ISO
For our low-light high-ISO tests, we have both standalone samples from the K-3 as well as a comparison between it and the Pentax K-5 IIs.
K-3 low-light noise test scene
Below is a set of long-exposure low-light samples taken from out-of-camera JPEGs with noise reduction set to auto. As before, click on any thumbnail in the table below to view the original 100% crops and browse.
ISO | Sample | ISO | Sample |
| 100 |  | 200 |  |
| 400 |  | 800 |  |
| 1.6 |  | 3.2 k |  |
| 6.4 k |  | 12.8 k |  |
| 25.6 k |  | 51.2 k |  |
At night, it is much easier to notice the presence of noise than during the day. As before, we see a noticeable drop in image quality at ISO 1600 and again, more significantly, at ISO 6400. The shadow detail is very good up to ISO 800, even though noise is prominent unless you're shooting at ISO 100.
But what about RAW mode? All the test photos on this page and on the previous page were taken in RAW+, so we did have a chance to analyze both file formats carefully. Even though the JPEGs are indicative of the camera's overall image quality, RAW files allow you to more effectively reduce noise and recover detail, and they will therefore normally yield much more impressive results. The files below have been processed in Adobe Camera RAW with subjective noise and detail adjustments.
ISO | Sample | ISO | Sample |
| 100 |  | 200 |  |
| 400 |  | 800 |  |
| 1.6 |  | 3.2 k |  |
| 6.4 k |  | 12.8 k |  |
| 25.6 k |  | 51.2 k |  |
Although the same general trends in image quality apply, it's clear that RAW mode gives you a lot more to work with.
Now, let's compare some K-3 JPEGs to K-5 IIs JPEGs. The test scene we chose is shown below:
K-3 vs K-5 IIs test scene
In this first set of comparisons, we're looking primarily at shadow detail and color. All photos are 100% crops of unscaled out-of-camera JPEGs.
Pentax K-3 | Pentax K-5 IIs | |
| ISO 100 |  |  |
| ISO 200 |  |  |
| ISO 400 |  |  |
| ISO 800 |  |  |
| ISO 1600 |  |  |
| ISO 3200 |  |  |
| ISO 6400 |  |  |
| ISO 12800 |  |  |
| ISO 25600 |  |  |
| ISO 51200 |  |  |
Here we see again the K-3's improved white balance. At higher sensitivity settings, it does exhibit slightly more noise and less shadow detail than the K-5 IIs, but color detail seems to be unaffected. The added resolution should help mitigate the increase in noise during post processing, however. Scaled examples will follow in our conclusion.
In the second set of comparisons, we can more easily see the presence of noise:
Pentax K-3 | Pentax K-5 IIs | |
| ISO 100 |  |  |
| ISO 200 |  |  |
| ISO 400 |  |  |
| ISO 800 |  |  |
| ISO 1600 |  |  |
| ISO 3200 |  |  |
| ISO |  |  |
| ISO 12800 |  |  |
| ISO 25600 |  |  |
| ISO 51200 |  |  |
We observe that the K-3 delivers superior image quality up to ISO 800 thanks to its added resolution. At ISO 1600 and above, it exhibits more noise but overall, we'd say that it holds its ground rather well with those extra megapixels.
On the next page, we will repeat our field tests in the studio and then make a verdict about the K-3's overall image quality.
