[brofkand]

Anyone know the native ISO of the K7? It isn't necessarily the lowest ISO in the menu. Is it 100 or 200?

[Rondec]

It is 100, the same as the K20. The Kx on the other hand has a base iso of 200 -- expandable to 100.

[Raybo]

IIRC it's iso 200, iso 100 is firmware based.

[Kirivon]

If you look at the dp review, the K-7 has better DR at ISO 100 than 200, whereas the K-x has better DR at ISO 200 than 100. It isn't definitive, but it seems to indicate that the K-7's base ISO is 100.

[Raybo]

If you look at the dp review, the K-7 has better DR at ISO 100 than 200, whereas the K-x has better DR at ISO 200 than 100. It isn't definitive, but it seems to indicate that the K-7's base ISO is 100.

Here's a quote from DP when they did the K20 review, i'm guessing it also has to apply to the K-7.

"Enabling D-Range doesn't appear to change the exposure yet is only available from ISO 200 upwards which suggests the sensor's native sensitivity may be ISO 200, hence offering slightly improved dynamic range at that setting."

[pcarfan]

Native iso is 100 for the K-7

[pcarfan]

Here's a quote from DP when they did the K20 review, i'm guessing it also has to apply to the K-7.

"Enabling D-Range doesn't appear to change the exposure yet is only available from ISO 200 upwards which suggests the sensor's native sensitivity may be ISO 200, hence offering slightly improved dynamic range at that setting."

DPR got that assumption wrong. The only reason the k-7 limits the iso to 200 with extended dynamic range, is with that option the image is actually taken with 1-stop less iso than what you set in the camera. So, if you choose iso1600 and take a shots with extended dynamic range, then the shot is actually taken at iso800. So, the minimum iso for this feature has to be 1-stop higher than the lowest iso possible, and has nothing to do with native iso. this was studied and explained by Gordon Good in DPR.

Hope this helps.

[Raybo]

DPR got that assumption wrong. The only reason the k-7 limits the iso to 200 with extended dynamic range, is with that option the image is actually taken with 1-stop less iso than what you set in the camera. So, if you choose iso1600 and take a shots with extended dynamic range, then the shot is actually taken at iso800. So, the minimum iso for this feature has to be 1-stop higher than the lowest iso possible, and has nothing to do with native iso. this was studied and explained by Gordon Good in DPR.

Hope this helps.

Now I know!
Thanks for the info pcarfan.

[blende8]

DXO mark writes that the lowest ISO of the K7 (100) equals about real ISO 85.

K7

[jeffkrol]

If you look at the dp review, the K-7 has better DR at ISO 100 than 200, whereas the K-x has better DR at ISO 200 than 100. It isn't definitive, but it seems to indicate that the K-7's base ISO is 100.

One of the definitions of base iso is the one with the most dynamic range... so yes it can be "definitive". That said most cameras will not fulfill this exactly at the iso notches presented. It may be 123 or 237 ect...
Of course all this is subject to interpretation like iso itself....... The wiki article is quite good...
Film speed - Wikipedia, the free encyclopedia
The ISO standard 12232:2006[14] gives digital still camera manufacturers a choice of five different techniques for determining the exposure index rating at each sensitivity setting provided by a particular camera model. Three of the techniques in ISO 12232:2006 are carried over from the 1998 version of the standard, while two new techniques allowing for measurement of JPEG output files are introduced from CIPA DC-004...................
The saturation-based technique is closely related to the SOS technique, with the sRGB output level being measured at 100% white rather than 18% gray. The saturation-based value is effectively 0.704 times the SOS value.[17] Because the output level is measured in the sRGB output from the camera, it is only applicable to sRGB images—typically TIFF—and not to output files in raw image format. It is not applicable when multi-zone metering is used.
....................
Despite these detailed standard definitions, cameras typically do not clearly indicate whether the user "ISO" setting refers to the noise-based speed, saturation-based speed, or the specified output sensitivity, or even some made-up number for marketing purposes. Because the 1998 version of ISO 12232 did not permit measurement of camera output that had lossy compression, it was not possible to correctly apply any of those measurements to cameras that did not produce sRGB files in an uncompressed format such as TIFF. Following the publication of CIPA DC-004 in 2006, Japanese manufacturers of digital still cameras are required to specify whether a sensitivity rating is REI or SOS.[citation needed]