[kypfer]

Is the Shake Reduction feature on the K-5 purely mechanically sensor based or is there an element of optical sensing as well?
I appreciate that the focus indication has problems with small-aperture lenses and I often find myself relying on the image in the viewfinder to set the focus, with long tele-photo lenses. If I get it wrong the foreground or background is clearer than the subject then it's my mistake - I accept that.
Occasionally, however, everything looks like a case of camera shake and I can't decide why. The camera is on a reasonably good tripod and I'm using a cable switch release and when it works it works quite well, but I don't seem to get anything like the quoted four stops of shake reduction mentioned in the handbook (page 139)
The only factor I can't isolate is the effective small aperture of the long lens, 500mm f/8 + 2x, so effectively 1000mm at f/16 ... am I simply expecting too much?
T.I.A. for any insights or similar experiences

[Unregistered User 8]

Hi kypfer, when using a tripod, it is recommended to turn the SR OFF. Here is a thread dealing with this question. Good luck.

Shake Reduction when using a tripod? - PentaxForums.com

[pschlute]

No optical sensing in the SR system. If you are on a tripod SR should be turned off

What shutter speed are you using ? Is the tripod and head rated for the weight your are putting on it ? Shutter speeds in the range 1/30-1/250 may cause a shutter-shock induced wobble of your setup. Try using MLU which may assist.

Manual focus will be much easier in LV using 100% zoom

[Skodadriver]

Not to forget using a time delay, mirror up image take.

[stevebrot]

Is the Shake Reduction feature on the K-5 purely mechanically sensor based

It uses inertial sensors.


Steve

[kypfer]

Thanks for all the answers so far Typical exposure would be around 1/1500-1/2000 with 6400ASA sensitivity. I've tried lower and higher sensitivity settings with little success, also with and without the Shake Reduction feature activated seems to make little difference. I'd been using the Shake Reduction simply because I was aware of very slight camera vibration on the tripod and was anticipating being able to compensate for it. The mirror lock-up feature is not very helpful in my scenario, mostly because I'm trying to photograph somewhat distant wild birds that will un-cooperatively move about when I'm trying to photograph them


The "zooming in Live-View" option is not one I've tried (or was aware of), so I'll give that a go next time I'm out


My next trial, when I can arrange a suitable support, will be for a much more damped support for the camera/lens. I'm thinking "bean-bag" for want of anything else, so if anyone has other ideas I'd appreciate them.


At least I've managed to confirm the electro-mechanical nature of the sensors involved so can ignore any reservations I had about small apertures

[pschlute]

Typical exposure would be around 1/1500-1/2000 with 6400ASA sensitivity

Ok, you should not notice any shake at those speeds caused by the shutter, but if you are pressing the shutter button by hand you can cause some shake. The SR system will not make any difference at those speeds, on or off.

perhaps post some pictures with full exif where you are not happy with the results.

[UncleVanya]

Beefier Tripod is the first suggestion. Also remote release via IR or wired remote. And as said above - post a few of the photos with full exif to help us see the issue.

(Oh and maybe just maybe - are you using a filter? On Telephoto shots those can be a problem for some people. I know that will not cause motion blur but I haven't see the shots yet. )

[kypfer]

Very many thanks for all the suggestions, comments and helpful links

Having the confidence to disable Shake Reduction (and leave it off) made me look into more mundane reasons for my less than reasonably perfect photos.

I introduced a modicum of damping to the system, mostly by using the tripod as a bipod and leaning the whole assembly on a solid padded surface, the point of contact being the base of the pan/tilt head. This made a significant difference.

I can now recognise that one of my lenses, an old Tamron 200-500mm f/6.9 with a Tamron SP 2x converter fitted, is limited by colour fringing. The lens alone seems to work perfectly adequately

My other lens, a Tamron 500mm f/8 mirror isn't affected (so much) by colour fringing with the same 2x adaptor fitted, but of course it's fixed focal length, which can make finding the subject in the first place rather more hit-and-miss and depth of field can be an issue if there's more than one subject, at differing distances, in the frame.

Nevertheless, I feel I've made significant advances in my quest for "almost perfection" without forking out for expensive modern autofocus glass ... maybe next step would be to buy a lottery ticket

Just one point, re the use of magnification in Live View ... that's a young man's game ... with the limited close-focus caused by advancing years I can't actually get close enough to the viewing screen to judge the critical focus without the whole thing going out of focus ... time for another visit to the optician


Thanks again all for the help and advice. I now have the confidence to press on improving my technique without the nagging feeling that I'm fighting the technology

[UncleVanya]

A tip for your mirror lens, invest in an astronomy or shooting type red dot finder. These make finding the subject much easier. Some are setup with hit shoe mounts others your going to have to determine how to mount to the lens. Keeping this calibrated to the lens may be a little complicated.

[kypfer]

A tip for your mirror lens, invest in an astronomy or shooting type red dot finder. These make finding the subject much easier. Some are setup with hit shoe mounts others your going to have to determine how to mount to the lens. Keeping this calibrated to the lens may be a little complicated.

I used to have one of those on my 12-bore over-&-under ... I've a sneaking suspicion it's still lurking at the bottom of a drawer in the hall cupboard. I'll have a dig about later!
Thanks for the idea