Originally posted by madbrain Bracketing in Tv mode with fixed ISO would change just aperture as function of shutter speed. I'm actually going to try that now.
Actually not bracketing - just set fixed ISO, Tv mode, and switch shutter speed with a dial to let the camera choose aperture.
Just did these tests. Shot at ISO 3200, shutter speeds between 1/40 and 1s (could not go to 2s because I reached F22 at 1s, which is the smallest aperture on D FA 28-105).
I did only a single shot for each aperture.
My two best shots were at 1/13 and f/7.1, and 1/10 and f/8 . These were the sharpest. There is no blur visible in any shot faster than 1/8 f/9.
Blur only shows up at 100% at 1/5 and f/11 . Gets progressively worse until 1s / f/22.
The widest apertures, wider than f/7.1, actually have significant vignetting in the corners. Probably something that can be easily corrected in post.
For the most usable image, that needs no NR in post, no vignette correction, the ISO3200 1/13 f/7.1 or 1/10 f/8 are the best. Both could be printed large, cropped and enlarged.
Incidently, when I first started my tests, I had set shutter at 1/20 and was surprised to get a blurred image. Actually, my trigger was set to "remote control", which disabled SR in the camera. As soon as I switched it to "single shot", SR came back.
Very obvious the K-1 II SR has a massive effect for this shooter.
Here is the best image at 1/13s :
Or pixel-peep all 36MP from
https://i.imgur.com/EQz0xla.jpg
---------- Post added 05-12-18 at 02:45 AM ----------
Originally posted by biz-engineer Visibly sharp at 2 sec. exposure with the 15-30. That also my experience with the 15-30, in shadows, handheld, and it impressed me.
The 15-30 is big $$$ though . Wide range seems to be the most expensive to get for Pentax FF.
To that effect, I bought a Tamron 1.4x Pz-AF FF teleconverter on ebay a week ago. I tested it outdoors with my Sigma 10-20 f4-f5.6 DC . It vignettes at 10mm (15mm equivalent), but is usable at 11mm (16.5 equivalent).
That Sigma was the most expensive lens I ever bought, $500 on Amazon ten years ago. The TC was $150 last week. Poor man's wide lens solution. But hey, it's not $1200.
Time to try it indoors now. Will be interesting to see what I can handhold. I wonder if the stabilizer will get confused since it gets the focal length from the electronic contacts, and doesn't know there is a TC in the mix ... That may be a downside of having a TC. Time to find out.
Last edited by madbrain; 05-12-2018 at 02:50 AM.