M lens and earlier, what settings ?

Take your point, Algi, but there are several points on the model in these resized images where subtle differences can be discerned (e.g. the detail in what would be the model's left foot). In retrospect, it would have been better had I used a tripod; thereby avoiding the need to re-focus between each shot. Additionally, I could have done more to even out the exposure differences at the pp stage. In my defence, however, I did describe the comparison as 'rough-and-ready'

Your shot of the nuthatch is a good example of just how forgiving the K5's sensor and Prime II imaging engine can be

All the best,

Jon

M Mode is Manual mode - TAv is Auto ISO mode. They're different!
You cannot get auto ISO in anything other than TAv mode which requires a lens that can have the aperture set from the camera body. TAv mode IS Auto ISO mode - and you cannot use it without an appropriate lens.

The usual way to get the full range of aperture settings from a non A lens (eg an old K or M lens) is to set the camera to M (Manual) and pre meter with the green button. An excepetion is to use one of these lenses wide open when you can set the metering mode to Av where it will make the exposure using the widest aperture of the lens. Stopping the lens down won't alter the expose so it will gradually become more and more underexposed depending on how small the aperture is set. It could be that one of those underexposed settings gives a better exposure than the metered setting. That's because some subjects do require an exposure less than the meter suggests. Should the lens being used not allow open aperture metering (old M42 pre-set lenses for example) these would work in Av mode but probably not reliably at small apertures (it would depend on the amount of available light.)

Should Pentax uncripple the mount in a new camera then it would be expected to work with the old non 'A' lenses which would also enable us to use the old K and M lenses in just the same way we did on our ME's and MX's etc. all that time ago. That is allow full use of a K or M lens automatically in Av or even TAv modes.

John

It would have made a more reliable comparison to show each of the shots without any PP at all as this has masked the differences. Yes, the lens will stop down to whatever you set it to and you can recover the underexposed exposures up to a point. But that isn't Auto ISO, it's more akin to underexposing a film and push processing it.

John

Fair point so here they are:

[img]http://farm8.staticflickr.com/7106/6989056372_c28d76eb53_o.jpg" class="comment_image" />

1 by Dr 'B ', on Flickr[/img]

[img]http://farm9.staticflickr.com/8164/7135140879_26e246a0f4_o.jpg" class="comment_image" />

2 by Dr 'B ', on Flickr[/img]

[img]http://farm8.staticflickr.com/7253/7135141271_d2844e86e5_o.jpg" class="comment_image" />

3 by Dr 'B ', on Flickr[/img]

Please be aware that before resizing, I checked the EXIF for each image and discovered that prior to taking the shot at f/5.6 I had applied +0.3 EV compensation; something I had not realised earlier I would have done this 'out of habit' after viewing the histogram for the first shot at this aperture and deciding that it was too far to the left. To compensate for this and facilitate comparison, I compared the histograms (RGB channel) for all 3 images and then reduced the mean and standard deviation for the image shot at f/5.6 to be within the same range as that for the others by applying a brightness adjustment of -30.

Apologies for not having realised this earlier

Begining to regret having got involved

Jon

It would need an example where only one thing gets changed, ie the aperture.
There's just too many variables in those shots so it get confused.

John

God willing !
Pete