K5II - centre focus point - AF at f2.8 - What?

I think that this is a reference to the aperture required at the lowest brightness figure quoted as being the autofocus operating range. For example, I have a K30 and in the specification (page 10 of the Appendix in the operating manual), it says that the autofocus operating range is EV -1 to 18 (ISO 100). As EV -1 corresponds to moonlight, I interpret this as meaning that I should expect autofocus on the K30 to work in moonlight, providing that I have a lens fitted that has a maximum aperture of f/2.8 or wider (assuming that f/2.8 is the relevant figure for the K30 also).

I also have a K200D and the specification says that the autofocus operating range is EV -1 to 18 at ISO 100, using a f/1.4 lens. The K30 autofocus system is, therefore, two full stops more sensitive than that of the K200D (again, assuming that f/2.8 is the relevant aperture). I guess folks can look up the corresponding figures in their K5 and K5II manuals.

I can only guess at what the reference to Canikon cameras focussing at f/8 means. Presumably a bit of Googling would reveal the autofocus operating range for non-Pentax cameras (or download the operating manual for a Canikon camera and look it up)

Andrew

If the K-5II does contain f/2.8 high-precision AF points
it should have been picked up by the reviews It is
after all a major improvement.... maybe the trap in focus
will work more accurately now I've not read them
so I don't know.

My 96 year old Aunt has been asking Pentax for this for years!
She will be pleased

'

Out of curiosity, I did.

The K-5 is EV-1 to 18, the K-5 II is EV-3 to 18, but I can find no reference to aperture that this refers to.

All I know is that the K-5 II is awesome at focusing in very low light with a f2.8 lens.

In a similar vein, I read that the sensor in the K5II is not the same as that in the K5, it having been redesigned - something to do with the size of the photo-sites? Only saw this once.

http://www.pentax.co.uk/en/digital-slr/K5-II.html

It actually states on the Pentax K5-II site......

SAFOX X can work with luminous flux based on F2.8 levels in addition to that of F5.6.
This increase the AF accuracy drastically when using with very fast lenses.

Strange that no one seems to have tested this accuracy with a lens of less than f/2.8 ...... say FA 50mm f/1.4 .... It's the 1st thing I would have tried if I had a Mk, II
The K-5 AF doesn't impress me it's probably within the DOF, but no better.

'

did first wedding yesterday since moving to Pentax, K5II + 50-135 2.8 exceeded all expectations at the reception, focusing quick and spot on made me really chuffed I switched systems

Where did you read this?

I have done extensive testing with the da 50mm 1.8 and the F 50 mm 1.4 and at wide open apertures the mkii is nearly always spot on with focus...

Wish I could remember! It was in an on-line piece before the K5II launch.

[/quote]Sorry, I think I was thinking of the image sensor rather than the AF sensor. Whoops

Shot a wedding today with Shaun Wilson and used the K-5iis and K-5 mk1. Used only two lenses, Sigma 105mm DG EX Macro and DA 17-70. The two lenses were interchanged between the cameras.

In a nutshell, the K-5iis blew the K-5 completely out of the water, mainly due to the sublime focussing accuracy. It is a demon in low light and nails accurate focus almost 100% of the time. In a wedding shoot situation, this is gold dust. By comparison, the K-5 was hit and miss at best and missed focus 50% of the time.

I will be buying another K-5iis as soon as the price comes down and will be trying (again) to re-calibrate the K-5.

Regards
David

I shot a gig last night and left my k-5 mki at hone exactly because of the lack of focus accuracy. First gig I shot with one body in over 5 years.

I wish the extra £100 trade in was on at srs as my order for a second mkii would be in..

I wish I could justify trading my two K-5's up for a couple of K-5II's.

I shall be holding out for the next model