Tuesday, February 17, 2009

Nikon D70 all manual

I have a Tamron 500/8 SP lens that i bought for a Canon A1 years ago. I wanted to use it on my Nikon D70, but it took a little figuring out, for me at least. Basically, one just attaches it and checks the histogram to set the shutter speed in manual mode (rotate the mode dial to M, use the main (back) dial to set the speed). The aperture is fixed. Here are a few shots that demonstrate this:

Not a lot of dynamic range, but hey: they were ducks on a pond...

Wednesday, February 4, 2009

OSX ssh

I have had ongoing problems with OSX's ssh. Connections would essentially time out when transferring a lot of data. Others have too, see http://www.speedguide.net/faq_in_q.php?category=89&qid=129 and http://lists.apple.com/archives/Macnetworkprog/2006/Oct/msg00030.html for example. I have packet captures that i'll try to post here. Quick fix is "sudo sysctl -w net.inet.tcp.delayed_ack=2".

More: turning other parameter dramatically increases OSX's performance on high speed links. See http://www.psc.edu/networking/projects/tcptune/ for example. I created /etc/sysctl.conf than contains:
More still: the delayed_ack seems to be the critical one...