[markos]

Hi,

I am thinking of entering the seemingly very confusing world of flash. After reading around the subject a bit, I thought I could get a mid-range P-TTL flash for my K20D and then be cooking on gas! However, I also read that when you have a split-screen installed it messes around with the exposure and whatnot. If there is any truth in this it could be a bit of a deal breaker...

On a further note would putting the flash into auto mode help? Using an old flash with an auto mode like the AF280T, or would the hypothetical screen problem affect all flashes?

Thanks for any replies!

[Ash]

Your K20D does not support TTL so the 280T may not be all that easy to use - some say you can throw it in A mode, but it will probably give you inconsistent results. Better off going manually with such flashes.

A P-TTL flash makes things a little easier since it has the ability to talk to the K20D and get exposure right automatically (at least on paper). Shouldn't be much drama with something like a Katz-eye split screen, but other third party screens may cause metering inconsistencies.

Look into the strobist.com website for more info on the topic.

[Matjazz]

First, TTL doesnt work with K20D P-TTL does. So the AF280T is out of the question as it will fire full power when used on K20D in TTL mode. On K20D you can use three modes: P-TTL, Auto and Manual.

Second, the impact that split prism focusing screen has on mettering depends on widest aperture of the lens and quality of focusong screen. This affects normal (daylight) shooting and P-TTL flash.

From my experience a good split prism in combination with f5.6 or less lens does not affect mettering.

[SOldBear]

Your K20D does not support TTL so the 280T may not be all that easy to use - some say you can throw it in A mode, but it will probably give you inconsistent results. Better off going manually with such flashes.

Have you yourself tried the Pentax AF280T?

"Inconsistent results" - It renders correct exposures better than my AF540FGZ in P-TTL.

Please read this thread on AF280T.

I also read that when you have a split-screen installed it messes around with the exposure and whatnot. If there is any truth in this it could be a bit of a deal breaker...

The split-image screen does have an impact on exposure, but unnoticeable (at least with my K10D) in center-weighted and matrix metering modes. Spot-metering becomes very unreliable.

I twice tried the split-image screen with my K10Ds, then gave up for LL-60 screen.

[Ash]

Have you yourself tried the Pentax AF280T?

"Inconsistent results" - It renders correct exposures better than my AF540FGZ in P-TTL.

Please read this thread on AF280T.

I have seen this thread, and did have the little beast of a flash at one stage. I tried it both on my K100D and K10D - sold it off before my K20D.

Used it in manual mode - that was how I ensured it gave me consistent results.
Otherwise it was inconsistent for me - seeing as though it's not TTL on these cams, how can it be?

The fact that you get good results with your cam is quite fortunate, though I'm personally much happier with my 540 in P-TTL mode.

[markos]

Cheers for your replies, very helpful and intersting. As a side note i did splash out and get a katz eye (not the optibrite - gotta scrimp somewhere eh?) and i have had no problems whatsoever. I think I'll take a chance and get a newer P-TTL flash!

-markos

[innershell]

Got the basic KatzEye with no optibrite and haven't really had an issue with exposure. If exposure is a little off, that's what EV compensation is for.

[Russell-Evans]

I am thinking of entering the seemingly very confusing world of flash. After reading around the subject a bit, I thought I could get a mid-range P-TTL flash for my K20D and then be cooking on gas! However, I also read that when you have a split-screen installed it messes around with the exposure and whatnot. If there is any truth in this it could be a bit of a deal breaker...

P-TTL uses matrix metering regardless of what is set on the camera, so you probably would be fine technically, but there may still be an issue. I assume you have a split screen because you are using older manual lenses? If so, then P-TTL isn't available for those lenses if they don't have an auto aperture setting. You may be better off with an auto flash in this case.

Thank you
Russell

[Mike Cash]

I daresay the AF280T performs just fine in Auto mode.

I had a P-TTL flash....and shed not a single tear when I sold the useless piece of crap. Now I do everything with some old flashes (AF200T, AF280T, National PE-3057) in either manual or auto mode. I wish I had never bothered with the P-TTL to begin with.

[Nesster]

While I've never used a p-ttl flash long enough to know its consistency... I can vouch that TTL is not necessarily the panacea people seem to think it is. Depending on the situation (i.e. in most situations) plain flash mounted thyristor sensors do just fine - and consistently so.

I have the AF280T and AF200T, and while not as accomplished as Mike, I use both in Auto on all sorts of cameras, with excellent results. Actually, I have used them in 'ttl' mode with the K100D and ZX-L - the AF280T does not flash at full strength with the K100d, but rather goes into the Auto mode. On the ZX-L it does the TTL bit.

As with any metering system, shooting pale things close up on white foreground with dark background will fool nearly any system, whether matrix or not, flash or not, ttl or p-ttl... there are times when one has to remember to think. Thank god for that, so our photography hasn't degenerated to a George Jetson level (push one button).

[res3567]

Thank god for that, so our photography hasn't degenerated to a George Jetson level (push one button).

Ohhh! I thought that is what our modern DSLR and flash combo was suppose to do!