From my experience, there are two types of CA.

1) Where the lens shifts some colours more than others. Try taking a photo of newsprint and examine in Photoshop at 200%. You may see red or purple fringing.

2) Highlight CA. Some of this is perhaps unavoidable. Two of my most expensive Pentax lenses exhibit this under very bright highlight conditions (SMC-F 100mm/f2.8 macro and the new SMC-DA 12-24mm/f4) The amount of CA varies with the quality of the lens. With the two lenses I mentioned, it's probably not visible in a print - just when you blow up to 200% in PS.

Type (1) can be fairly easily removed. Photoshop CS2 has a CA removal feature in both RAW conversion and lens correction filters. I have just started using PTLens (which is very reasonably priced) and can remove much of the CA, as well as barrel/pincushion distortion and vignetting. Definitely worth a try

Yet I have found that nothing except some colour adjustment action, or manual removal will get rid of type (2) CA (which can still remain after removing type 1). But definitely get rid of type 1 first... then do the second.

Failing that... convert the image to B&W

Matt

Don't forget, that if you use spot metering in "P" mode, you must lock the exposure! i.e. point the spot at the Zone V area (palm of your hand is a good one too), then lock the exposure and reframe.

If you use spot-metering, it's a good idea to use the "M" mode. That way you can just press the green button to get a good exposure (assuming you've pointed it at a Zone V area first!) - and then the exposure will stay. On the *ist-D it will also show you in the viewfinder bargraph just how much over, or under exposed the scene is - that way you can move the spot around the view to guage the level of exposure for each element and adjust the manual settings appropriately.

If you're shooting fast and in auto - shoot RAW. Then you have quite a bit of lattitude after the shoot at the RAW processing stage

Matt

Mario,
As George rightly says, the AF360-FGZ and AF540-FGZ are the best match for all your cameras, even though they will not do wireless P-TTL on any of them.

Note: Both the AF360 and AF540 can be switched to "dumb" slave mode and will trigger off any flash - but you'll need to use them in Manual or Auto mode (not TTL/P-TTL).

The AF360/540 will give you:
* TTL on the MZ5, P-TTL on the K10D.
* Auto (where the flash does the metering, not the camera, but you have to dial in the appropriate aperture on the camera and set the ISO rating on the flash) and Manual flash on all cameras.

Metz SCA adapters only support TTL (not P-TTL). The MZ5 does TTL flash only, but the K10D only does P-TTL. The latest adapter is the SCA3702.


I have read that Samsung make a flash gun that's the same as the AF360... the "SEF 36PZF" which may be available
http://www.fotosense.co.uk/Samsung_SEF-_36PZF_Flash_Gun_for_GX_Series.asp?produc...
and
http://www.samsungcamera.co.uk/product/pro_acc_view.asp?prol_uid=1406&cat_ui...
It does bear a striking resemblence to the Pentax AF360-FGZ, and whether it's the same I couldn't possibly comment

Hope that helps!
Matt

LOL! With my eyes, especially in low light situations, I need the AF
Matt

Liam - the beep is a good point. However, apart from being distracting when you're doing low-light candids, it has another small problem. As you focus, if you rely only on the beep you could have focussed past the point and never be 100% sure you're actually correct.
That was my point regarding the AF red-light overlay. That too can light up as you cross the focus point. The only sure way to check is the green hexagon - that has indicates critical focus (and with the AF red-light overlay off, and beep off, I pay much more attention to it!).

Peter - I assume you're referring to my choice of lens. Yes, it's sickening isn't it I must say that once you've tried the Pentax f1.4 lenses you don't want to give them up easily... there's just something about them

Matt

Just a small thought:

When using the *ist-D with a manual focus lens, I was getting a number of "off-focus" shots.

Turned out I was instinctively relying on the red AF illuminator to guage focus. DOH!

The red AF indicator is not a guide for focus - it's the green hexagon at the bottom of the viewfinder that should be used!

Having realised this, I have disabled the "Superimpose AF area" in all my custom menus - as I only ever use the centre focus point.

...And now I can't decide which I like best: the SMC-A 50/1.4 or the SMC-F 50/1.4

Matt

I quite agree Kimbo! But then I haven't done any further tests lately, and am not even sure if I have any parafocal zooms left.
Perhaps there's some test that could be setup to try this out?
Matt

It's not down to multipoint AF. It's a question of how the SAFOX focusses. You'll notice that the *ist-D "knows" what lens is connected. Each lens has a 2-byte ID. In theory, it is possible for the camera to compensate for the given focal length/lens/aperture combination and focus on the HF point.

Maybe that's why some third party lenses misfocus? (Their ID reads as a Pentax lens, and the body focusses according to its table of values). Just a hunch, of course

Matt

Getting waaay off topic here

ROFL!

You can tell the *ist-D focusses at the hyperfocal distance when you use a parafocal lens. The focus is always off when you zoom, and it shouldn't be. Try the lens on a film Pentax (like the Z1) and the parafocal lens is fine.

It wasn't actually me that said it, but Pete (who runs this site and ePhotozine) who was told direct by Pentax. Whether it holds true for all firmware issues, I don't know.

Generally I do trust the AF, using only centre spot focussing. I'm too short sighted to get a good lock normally, unless I have an age to get the focus right (used the SMC-A 50/1.4 and missed too many shots). But then, yes, the AF does get it wrong at times!

Matt

Don:

Info available here: http://www.dofmaster.com/
This link ( http://www.dofmaster.com/charts.html ) will allow you to spit out a little chart for your lens and camera combination.

I have a freebie utility for my Pocket PC - "DOF" by Jonathan Sachs. (http://home.comcast.net/~jonsachs/)

Hope that helps
Matt