Here's a summary of what we've finally concluded about TTL support on Pentax DSLRs:

• Pentax *ist D: Full TTL support for the internal flash and any external TTL flash used with any lens
• Pentax *ist DS/DS2: TTL support for external TTL flashes only (Must be in M mode for manual lenses or when away from "A." Extremely fast apertures cannot be used)
• Pentax *ist DL/DL2: No TTL support
• All newer DSLRs (K100D, K10D, K20D, K200D, K-x, K-5, K-3, K-30, etc.): No TTL support

Sadly, even though the DS/DS2's both have the TTL sensor, TTL support for the built-in flash seems to have been disabled via firmware. Also, if P-TTL is available on the external flash, it will be used over TTL.

More clarification for DS/DS2 users:
-TTL features are identical in both models
-To obtain TTL with M, K, or M42 lenses (or when using extension tubes), the mode dial must be set to M.
-The built-in flash only supports P-TTL and therefore cannot be used with M, K, or M42 lenses.

Quick Definitions:
-TTL uses a real-time sensor to control lighting during exposure. This sensor is only avaiable in the *ist D, DS, and DS2 DSLRs.
-P-TTL calculates lighting before exposure using a preflash shot and does not function if the aperture value is unknown.

[GregNS]

> > Also, if P-TTL is available on the external flash, it will be used over TTL.
True, but . . .

Sorry Mo, but it might be useful to mention here that if the flash supports both P-TTL and TTL (like the Sigma EF 500 DG Super) then one can force the flash into TTL by moving the aperture ring on the lens (as long as it has one) away from "A" and setting the f-stop manually. Then the camera/flash system will revert to TTL.

[Adam]

Thanks for the clarification, although it goes a bit beyond the intention of my post

[RiceHigh]

> * Pentax *ist D: Full TTL support for the internal flash and any external TTL flash used with any lens

Nope. RTF of *ist D does not support TTL, it's P-TTL only. Only that MZ-S has TTL for RTF and P-TTL (only) for external flashes.

> * Pentax *ist DS/DS2: TTL support for external TTL flashes only (Must be in M mode for manual lenses or when away from "A." Extremely fast apertures cannot be used)

My experience with setting a FA lens at non-A position did NOT engage TTL mode and exposure was in a mess.

> Sadly, since the DS/DS2's both have the TTL sensor, TTL support for the built-in flash must be disabled via firmware. Also, if P-TTL is available on the external flash, it will be used over TTL.

Yes.

> -P-TTL calculates lighting before exposure using a preflash shot and does not function if the aperture value is unknown.

P-TTL rely heavily on the distance info after AF (probably MF too) completes. So, if there was mis-focusing, the exposure will be off too.

[Adam]

My experience with setting a FA lens at non-A position did NOT engage TTL mode and exposure was in a mess.

On the DS/DS2, TTL only works when mode dial is set to "M".

As for the D, it indeed supports TTL for all lenses, but not for ISO ranges above 800. This has been confirmed, so let's not be confusing all the visitors here.

[BarneyCG]

Pentax *ist DS/DS2: TTL support for external TTL flashes only (Must be in M mode for manual lenses or when away from "A." Extremely fast apertures cannot be used)

Sorry to drag this up again but surely the bit in brackets is obvious since when using manual or "A" lenses but not in the "A" setting you must use M mode anyway for the metering system to work

[Adam]

It's not quite obvious for everyone, so we'll be leaving it there for clarification.

Adam
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[Dana G]

Apparently the new firmware for the K10D adds support for TTL flash, but I don't know all the details.

[sklathill]

Apparently the new firmware for the K10D adds support for TTL flash, but I don't know all the details.

Really? That would be interesting...but nothing like that is found in the documentation with the firmware update. Besides, wouldn't TTL require a physical TTL sensor in the body?

[Adam]

Lol, that's definitely not true.

The K10D doesn't have the TTL sensor, so it cannot physically support TTL. Let's not be confusing people, here...

[Denis]

Lol, that's definitely not true.

The K10D doesn't have the TTL sensor, so it cannot physically support TTL. Let's not be confusing people, here...

The K10D has P-TTL but only with the Pentax flash AF360 and AF540 according to the booklet. Higher Sync mode is available while using these flashes.

Denis.

[calicojack]

Hi all. I'm new here at the Forums and have a question maybe someone can clarify for me. I've read the entire DSLR's Support TTL Flash thread. No, I'm not confused by it, but.... I'm just working on the purchase of a K10D (my first DSLR). I've been a Pentax user since 1968 (or so). From my last film SLR set up, I have an AF280T flash unit that I'd like to use with the K10D. I recently sent Pentax customer service a question about using the two in TTL mode. I thought I might have sent it to an incorrect email address, so I sent it twice. The next day, I got 2 responses from 2 different people in "Pentax Imaging Customer Support". Of course, you know that one said "No, unfortunately, your AF280T will not work on the K10D" and the other said "That flash will work in the TTL mode." Does anyone have a definate yes/no answer on this? I note that toward the end of the thread, someone mentioned that a firmware upgrade allows TTL functions with older flashes. Has anyone done the upgrade and tried a TTL on the K10D yet?
Thanks,
Brian (aka Calico Jack)

[Cideway]

Hi all. I'm new here at the Forums and have a question maybe someone can clarify for me. I've read the entire DSLR's Support TTL Flash thread. No, I'm not confused by it, but.... I'm just working on the purchase of a K10D (my first DSLR). I've been a Pentax user since 1968 (or so). From my last film SLR set up, I have an AF280T flash unit that I'd like to use with the K10D. I recently sent Pentax customer service a question about using the two in TTL mode. I thought I might have sent it to an incorrect email address, so I sent it twice. The next day, I got 2 responses from 2 different people in "Pentax Imaging Customer Support". Of course, you know that one said "No, unfortunately, your AF280T will not work on the K10D" and the other said "That flash will work in the TTL mode." Does anyone have a definate yes/no answer on this? I note that toward the end of the thread, someone mentioned that a firmware upgrade allows TTL functions with older flashes. Has anyone done the upgrade and tried a TTL on the K10D yet?
Thanks,
Brian (aka Calico Jack)

They will function as manual flashes, or if they have an A sensor in the flash its self they will function in A, but no TTL as the camera doesn't have the required sensor.

[Ash]

The K10D has P-TTL but only with the Pentax flash AF360 and AF540 according to the booklet. Higher Sync mode is available while using these flashes.

Denis.

Hi all,
A newbie (and amateur) from Australia with a K100D.
Just wondering if anyone's tried the Digital Concepts flashes dedicated for Pentax dSLR.

I've picked up the 736AF, claimed to be P-TTL, and truthfully I'm not so well inclined to flash function, but testing it , the flash exposes correctly in all lighting situations except with bounce photography (mostly underexposes). This one doesn't have manual mode.

Any ideas about this range of flash?

[MEtoK110D]

That's really quite annoying, but I think it answers my question. I have a Centon FH85 flash with which I am very happy. It's quite a good one with swivel head, fill-in flash, off-camera cable and so on. I have a Centon "Pentax PX" module designed for my Super A and ME Supers and have managed to get hold of an AF module designed for MZ series cameras and the like. I did that because I have finally updated to a K110D.

I have neither the budget nor the desire to replace the flash. Amongst other things, I believe that I should get from the AF module an IR pre-flash to assist focussing?

However, it now seems that I can have either the built-in sensor on the non-AF module or the IR on the AF one, but in neither case is TTL going to work.

Is P-TTL, which I think I now understand having read this page, really an advantage? Does anyone have any useful suggestions or comments, apart from "Buy a new flash?" Have Pentax done the dirty on us by removing TTL or is there a good reason?