[rawr]

Great list!
Where do you get the data? Pentax/Ricoh seems to state different values for low light EV AF working range.

Data is direct from the specification pages of the camera manuals.

There is usually a different sensitivity range for the metering sensor compared to the AF sensor. Maybe that's what you could be seeing in some of the data.

Eg the K-5 II's SAFOX X is sensitive -3 to 18 EV, but the metering sensor works 0-22 EV.

Interestingly, from the K-3 onwards, where the AF is sensitive from -3 to 18 EV, the metering sensor also started to work down to -3 EV too (-3 - 20 EV). So now the KP, K-3II and K-1 all have metering that works in the deep dark (-3 - 20EV), along with their AF.

(645Z breaks the trend though - 645Z AF is sensitive to -3 to 18 EV, but metering works -1 to 21 EV).

METERING SENSITIVITY EV RANGE:

16 segment metering sensor:

0 to 21 EV: K20D
1 to 21 EV: K200D
1 to 21.5 EV: K-x, K-r

77 segment metering sensor:

0 to 22 EV: K-7, K5, K5II/s, K-30, K-50, K-70, K-S1, K-S2
2 to 21 EV: 645D

86k pixel metering sensor:

-3 to 20 EV: K3, K3II, KP, K-1,
-1 to 21 EV: 645Z

[fredralphfred]

I want to let everyone know that I find this discussion fascinating -- many things I hadn't considered, and many plausible explanations for the so-called low-light blues. Especially the anecdotal factor -- people's experiences vary. What does one word really mean to two different people?

[normhead]

Usually people like one lens more than another and will defend that choice too the death, inventing all kinds of attributes to justify their claims. But usually, they haven't actually run a side by side test.

[angerdan]

It get's interesting if you start to look at the combination of focal length&aperture considering the shutter speed.
What is Reciprocal Rule in Photography?

Shutter speed - Wikipedia
The ability of the photographer to take images without noticeable blurring by camera movement is an important parameter in the choice of the slowest possible shutter speed for a handheld camera.
The rough guide used by most 35 mm photographers is that the slowest shutter speed that can be used easily without much blur due to camera shake is the shutter speed numerically closest to the lens focal length.

For example, for handheld use of a 35 mm camera with a 50 mm normal lens, the closest shutter speed is 1/60 s (closest to "50"), while for a 200 mm lens it is recommended not to choose shutter speeds below 1/200th of a second. This rule can be augmented with knowledge of the intended application for the photograph, an image intended for significant enlargement and closeup viewing would require faster shutter speeds to avoid obvious blur.

Example with Pentax:

EV.....Lens
6,5... FA 31mm F1.8 AL Limited
6,5....FA* 24mm F2 AL [IF]
7,0... DA* 55mm F1.4 SDM
7,3... FA 43mm F1.9 Limited
7,5....FA* 85mm F1.4 [IF]
7,8....FA 77mm F1.8 Limited
8,0....DA 35mm F2.8 Limited Macro
8,0....HD DA 35mm F2.8 Limited Macro
10,5. HD D FA* 70-200mm F2.8 ED DC AW
10,5. FA* 80-200mm F2.8 ED [IF]
10,5. FA* 200mm F2.8 ED [IF]
10,5. DA* 200mm F2.8 ED [IF] SDM
11,0. FA* 300mm F2.8 ED [IF]
11,5. FA* 200mm F4 Macro ED [IF]
12,0. DA* 60-250mm F4 ED [IF] SDM
12,3. DA* 300mm F4 ED [IF] SDM
13,0. FA* 600mm F4 ED [IF]
13,0. FA* 300mm F4.5 ED [IF]
13,8. FA* 400mm F5.6 ED [IF]
14,0. FA* 250-600mm F5.6 ED [IF]
14,3. HD DA 560mm F5.6 ED AW

---

Last edited by angerdan; 10-26-2017 at 02:33 AM. Reason: readability

[normhead]

The rough guide used by most 35 mm photographers is that the slowest shutter speed that can be used easily without much blur due to camera shake is the shutter speed numerically closest to the lens focal length.

That's pretty much made irrelevant by Shake Reduction.

[TheOneAndOnlyJH]

Especially the anecdotal factor -- people's experiences vary. What does one word really mean to two different people?

Definitely agree. I'm only one person and I use "low light" to describe a whole range of situations, from inside my house to outside at dusk. Midnight around a campfire lit only by the flames is also "low light", but at least I call that "very low light." Someone else might use the same descriptions for wildly different circumstances.

[leekil]

That's pretty much made irrelevant by Shake Reduction.

Not irrelevant, really, but it should cause a shift in the shutter speed required. Like (1/focal length) - 5 stops worth of shutter speeds (depending on your camera model). Maybe subtract 5 EV from each line in the chart, assuming that the SR works uniformly over all focal lengths?

[UncleVanya]

It get's interesting if you start to look at the combination of focal length&aperture considering the shutter speed.
What is Reciprocal Rule in Photography?

Shutter speed - Wikipedia
The ability of the photographer to take images without noticeable blurring by camera movement is an important parameter in the choice of the slowest possible shutter speed for a handheld camera.
The rough guide used by most 35 mm photographers is that the slowest shutter speed that can be used easily without much blur due to camera shake is the shutter speed numerically closest to the lens focal length.

For example, for handheld use of a 35 mm camera with a 50 mm normal lens, the closest shutter speed is 1/60 s (closest to "50"), while for a 200 mm lens it is recommended not to choose shutter speeds below 1/200th of a second. This rule can be augmented with knowledge of the intended application for the photograph, an image intended for significant enlargement and closeup viewing would require faster shutter speeds to avoid obvious blur.

Example with Pentax:

EV Lens
6,5 FA 31mm F1.8 AL Limited
6,5 FA* 24mm F2 AL [IF]
7,0 DA* 55mm F1.4 SDM
7,3 FA 43mm F1.9 Limited
7,5 FA* 85mm F1.4 [IF]
7,8 FA 77mm F1.8 Limited
8,0 DA 35mm F2.8 Limited Macro
8,0 HD DA 35mm F2.8 Limited Macro
10,5 HD D FA* 70-200mm F2.8 ED DC AW
10,5 FA* 80-200mm F2.8 ED [IF]
10,5 FA* 200mm F2.8 ED [IF]
10,5 DA* 200mm F2.8 ED [IF] SDM
11,0 FA* 300mm F2.8 ED [IF]
11,5 FA* 200mm F4 Macro ED [IF]
12,0 DA* 60-250mm F4 ED [IF] SDM
12,3 DA* 300mm F4 ED [IF] SDM
13,0 FA* 600mm F4 ED [IF]
13,0 FA* 300mm F4.5 ED [IF]
13,8 FA* 400mm F5.6 ED [IF]
14,0 FA* 250-600mm F5.6 ED [IF]
14,3 HD DA 560mm F5.6 ED AW

I feel really dumb but I don't see what these numbers mean in front of each lens? 14, 3, 10,5, ?????

[MadMathMind]

The 645D has a CCD sensor. The K20D (and the K5 and later DSLR models after it) has a CMOS sensor. That might have something to do with it.

Sensor doesn't factor into PDAF. Nor into metering.

[leekil]

I feel really dumb but I don't see what these numbers mean in front of each lens? 14, 3, 10,5, ?????

I believe those are the minimum EV you can shoot at while using the 1/(focal length) rule with each particular lens. That EV would be the EV represented by the lens' maximum aperture and the 1/(focal length) shutter speed.

[UncleVanya]

I believe those are the minimum EV you can shoot at while using the 1/(focal length) rule with each particular lens. That EV would be the EV represented by the lens' maximum aperture and the 1/(focal length) shutter speed.

So the commas are decimal places! Ahhh, that's what triped me up.

[leekil]

He's from the EU, it looks like

[UncleVanya]

So the commas are decimal places! Ahhh, that's what triped me up.

He's from the EU, it looks like

Yup... I was just showing functional bias. LOL