K-3 - this one needs a service badly!

In this thread in Leads to Deals, we got talking about issues for the Sigma 100-300 F4, and it looks like my copy may need a new board to correct severe back focus - if that board is still available!

However, at Duxford today I took a lot of shots with the K3 set to AFC, 1st Shot Focus Priority and Focus Priority, either Medium or High Burst Speed, sometimes with Single Point Focus and sometimes with Expanded Area Focus - and with viewfinder focus confirmation - and very few, except a few ground movement shots, were actually in focus, thus very few keepers and especially the airborne shots .

Then, unfortunately near the end of the show, I changed to the old K5 for comparison - and then I started getting a few sharp airborne shots. Only a few because the K5 is so much slower to focus the screwdrive lens and then to lock on - but those that were in focus were much sharper than with the same lens on the K3.

Looks like a repair job for Johnsons (ouch!) unless some has some other ideas !

But maybe the lens is OK (although I still had to apply +10 backfocus adjustment on the K5 as well as the K3 - but it had more effect on the K5!)?

I was there with k3 and Da 300 combo. Similar problem also. 😕

Was thinking as it was a sunny warm day, could it be heat haze affecting the focusing?

Rob

It was pretty warm, but I didn't think it was that hot (certainly not much >30C because I really begin to suffer badly at those temperature levels!) and can't remember noticing any haze/shimmer and so I'm not sure that's the reason - and if it is, then I'm surprised I haven't seen anything to the same effect yet on the US forum from people who live in the much warmer parts of that country.

However, that's not say that the K3 can't be heat-sensitive - so, any others experienced anything like this today or before?

PS: Roughly where were you standing?

PPS: I have been there on days when it has been hotter with the GX10 & K5 without experiencing the same issues.

1st visit there so not familiar with the Base, but I was standing about 20yds away from the large dome building still under construction if that makes sense?

Rob.

That building is the American Air Museum building which is being completely refurbished (not being built!) - with only the B29 and B52 still in the building. I was about 200yds South of you, just to the North side of the Land Warfare Centre - and, in fact it was very crowded there and I should have been about another 150 yds further South on the steeper bank.

Anyway, we were in roughly the same area, so the location factor should not come into question.
PS: watching the weather forecast and the Cambridge area is likely to get some rain after lunchtime tomorrow

Just to add further bits to my first post:
- most of the time I had the OS switched ON, but when I switched it OFF then the images were even worse.
- anti-aliasing filter was switched OFF
- the body is at f/ware V1.21

I'm not the steadiest of hands(left handed too) so I'm sure my technique plays a part. But what I find works best for me is shutter priority fix iso(sometimes auto if changing light) single focus point with expanded to 9.
Then hi speed shutter with 1st shutter focus priority, and focus priority in Afc continuous.
Hold focus OFF.

Have same same version software.

Headed home yesterday as the sUn tired me out a little and did think about camping over but with the forecast didn't fancy packing up in the rain!!

Rob

Pretty similar settings except that I was using TAV as I normally do (generally ISO 200-1600), and Hold focus at High (Level 4) which I have seen recommended in several posts here and elsewhere.

John

PS: we had some rain late last night, and it's pretty murky in the London area but no rain this morning.

Hope you're having a better 2nd day.
I was gutted as I took my MZ-7 with a few rolls of b/w Ilford. Wanted to shoot some personnel in uniform. Unfortunately on the 1st frame the camera froze with mirror up!! 😕
Put new duracell batteries in and still no reaction, showed low battery??
(Date on packet 2020 purchased from Amazon)

Since I got back have tried some other new batteries purchased from my local store and hey presto it blumin worked!!
Must have purchased some duff batteries from Amazon.
Gutted and annoyed 😠

Not there today - good job when looking at the weather here in W.London although it is beginning to brighten up as I type.

I assume the MZ-7 takes (IIRC) 2x CR2 like my old MZ-5N (now sold) - but there appear to be fake duracells on the market in some places (Trading Standards found them).

Although I do buy batteries (notably Eneloops) from Amazon, if I want anything unusual I get them from CPC Farnell because they are part of a very large electronics distributor - the CR2 list is here - and they generally keep good stocks of up-to-date products.

Anyway, coming back to the K-3 issues, I've now downloaded the SD card to the PC and taken a closer look at most of the JPGs - it's now looking that the few flying keepers were generally at higher shutter speeds (320th) than I would normally use for prop planes and anything much slower was generally not that good. Did get at least 1 good/sharp shot of Red 7 (the 109) though!:
- Cropped to about 1/4 original frame area but no other processing at all (and all the shots before/after this one varied from poor to PBA!).

However, you can see that the 1/320th shutter speed was nearly too fast, so maybe it's me as much as the camera - I shall have to practice my panning techniques more often (:roll but I'm still not terribly convinced that the body is performing totally as it should.

In the short period that I owned the K-3 I could never work out the benefit of focus hold when doing Airshows. I thought the whole idea of that was to keep lock on the subject as it passed by something else .. which is unlikely when photographing a single plane in the sky.

BTW, made it to Yeovilton in the end, place was absolutely heaving and I left well before the jets at the end as I didn't want to get stuck in a free for all as people left the massive field that served as a car park. Maybe I have done too many airshows in the past few years as I was a bit bored with it all tbh, RIAT next weekend then Bournemouth and I may not bother for the following couple of years.

Mike

You could be right about focus hold - this was the first time I used it in Level 4 (High) mode, and maybe it did not have the desired effect but caused raised processor activity which then slowed down other functions detrimentally.

I have tried the focus hold when shooting the jets in the loop to specifically hold on the 1st jet when on the odd occasion maybe a 2 ship or more enter the viewpoint and I want to hold on the nearest subject. Didn't work for me anyways.

I personally leave the focus point unlocked (if this makes sense) so I can manoeuvre it around.

I assume the less the camera has to do the better! 😊

I had a similar set up last year, K5IIs with the DA*300, also found it was difficult to focus consistently, the lens is slow to focus and also slow to acquire a target, I was hoping that the K3's stronger focus drive would improve things, not so it seems.......

Andy
The Sigma certainly changes focus point much quicker on the K3 than on the K5 - have shown many times - and so the DA300 should probably exhibit the same sort of characteristic, but it will depend on
a) Whether the lens defaults to the screw-drive or the AF motor - and if it's the latter (which I suspect it is) then the lens is slower when it uses the screw-drive! (there is a lot on the US forum about attempts to disable the motors on DA lenses so they only use the screw-drive but not following that because I don't have any such lenses)
b) How long the focus movement is - the longer the movement then the slower the lens may be to reach the focus point (was told by Sigma that that is why the 100-300 F4 is faster to focus than the 150-500 HSM, because the latter has to move the elements further than the 100-300)
c) The camera body!