Hi Matt, any chance of elaborating on this?

Regards - Steve

I don,t know if they are interchangeable, but the Pentax part is available from Johnsons. The 'lever' part of the switch is relatively cheap around 5 GBP I think. The actual micro switch that it activates is attached to a small flexible circuit board. If the micro switch is broken, you will need to replace the board, cost is around 40GBP.

If you send me your email address via pm, I will send a copy of the K10D parts schematic.

Regards - Steve

Manual focus, M,Av and B exposure modes only. Strip out most of the in camera processing, output RAW only. Non crippled mount allowing use of K and M series lenses without needing the green button.

Regards - Steve

DA* 8-16 F4
DA* 24 F2
DA* 135 - 400 F4

Regards - Steve

Thanks Gwyn

Regards - Steve

It should be down on the Super A also. The return spring has probably become detached.

Regards - Steve

Limit now back in force.

Same here, maybe explains why the 5 uploads a week limit is not being enforced at the moment.

Regards - Steve

As it is a * lens, Pentax would recommend you send it to their offical servicing agents Johnsons http://www.johnsons-photopia.co.uk/JP%20Service%20Solutions_17.php

Why not give them a ring and explain the problem. They are based in Leek, so maybe even worth a visit. For calibration, they might need your camera as well. It is possible that the problem is because camera and lens are at different extremes of their production tolerances.

They do not charge for the initial inspection and if you decide not to have the work done, the only charge will be for return packaging.

Regards - Steve

After reading this thread I decided to use a gap between family commitments to fine tune the AF of my lenses for use my recently acquired K5.
The ability to fine AF was one of the key drivers for me, as I was always compromised with the K10. On my K10 the DA*16-50 and DA*50-135 both back focused (by differing amounts), but my FA50 F1.4 and FA 31Ltd both front focused. Interestingly on the K5 the two primes required no adjustment, the DA*s were +4 and +6 respectively.

So to the test, firstly I admit that the methodology was rough and ready, but I did take multiple shots on different occasions so for my camera/lens combinations the results are valid and repeatable.

1. Having consulted an EV chart, I noted that EV1 equated to using ISO 3200 @ F1.4 would require a shutter speed of between 1/15th and 1/8th of a second.

2. The subject was a finely printed document from my bank, placed flat on the floor under the shadow of a table.

3. I used FA 50mm F1.4 and FA31Ltd 1.8 wide open at closest focusing distances.

4. I used the fine tuning adjustment on the K5 to monitor its effect.

4. For the 'night' shots the room was lit by a single 16W low energy bulb. Using AV mode with centre spot metering this gave a shutter speed of between 1/10th and 1/20th of a second.

5. For the 'day' shots taken around 7:30am in the morning I used the same setup and waited until the cameras meter indicated the same range of shutter speeds.

Results
1. Both combinations K5/FA50 and K5/FA31 produced acceptable in focus images in both day and night EV1 conditions.
2. Moving the the AF fine setting by + or - 2 produced noticably worse results. Moving the adjustment by + or -4 produced significantly worse results.

Conclusion
I accept that the methodology is not perfect, I did allow time for the lenses to lock on, but there was little if no hunting. The 31ltd was very quick, a big improvement on the K10

For my purposes the combinations are fit for purpose. It is unlikely that I will be shooting down at EV1 levels very often, but it is nice to know that for me personally the results are acceptable.

Regards - Steve