Sanjeev Sabhlok's notes on technology, hardware, gardening

K 100D pentax camera personal notes

The Sigma 70-300 lens often ‘freezes up’ on K100D without warning. That is because some mishanding has loosened the aperture ring. The camera simply won’t recognise the lens when that happens.

Go to page 139 of the manual (softcopy available here) and look at the last paragraph on the page. The aperture ring is the first ring from the point where the lens is connected to the camera. The ring must not move (if it does, that means its setting is no longer working).

If the ring is moving, press the little black knob and move it so that the little white mark (peer below the ‘PENTAX’ flash system that over-hands this mark) is facing Number 22. At that point release the black knob. The aperture ring should become firm and stop moving. Now the camera is ready to work again.

Some guidance also available here: (Using Your Pentax K100D by Richard Grimes).

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Managing the wireless at home

Restricting access to wireless at home

  • Select ‘Wireless’ from left hand side.
  • Change the 10 digit password (WEP key it is called).

Apparently this is very weak security. Better security guidance is available at:…TemplateId=35798

MTU setting on wireless
Unable to access web site (or POP mail) from home. Was able to access email from mail2web (which uses IMAP), but not able to download POP3 to Eudora

a) Suspected a firewall issue. Checked. No problem there.
b) Cleared cache from Internet Explorer. Used Mozilla Firefox to rule out an Internet Explorer problem. No success.
c) Asked my ISP (scottsdale) if any problem with hosting. Everything was fine with them.
d) Finally, waited for an hour on phone to ask Optus if my website was visible from their end. Yes. It was.
e) Removed DLink router and directly linked cable modem to computer. Website came back alive! Clearly the dlink router was causing a problem.
f) checked Dlink website (australia) and troubleshooting hints. Stuff about MTUs. Changed them endlessly. Including using TCP optimiser to change computer MTU. No luck.
g) Reset router. No luck.
h) Downloaded next version of firmware. No luck initially, as my MTU was now at 600.
i) Reversed MTU to 1500, with the new firmware. Everything came back!

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