[Jewelltrail]

I have read at our forum that some flash mechanisms can destroy the electronics in our Pentax DSLRs. This has inspired a specific question for me:

Does anyone know if the Pentax AF160Sa is safe to operate with the K20d?

[GerryL]

I have read somewhere (no longer sure exactly) that all Pentax flash would work on new Pentax DSLRs (not fry the electronics), albeit not dedicated (TTL vs P-TTL).
Don't take my word for it though.
The best way is to test the trigger voltage of the flash in question.
Some say 12v below is ok (for Pentax) whilst others say that 6v is max (usually true for Canons)..but others go by the Canon one as it is the one usually said to be safe for DSLRs.
Why not just get the Pentax DSLR P-TTL dedicated ones so you will have all automatic controls and them some?

[GerryL]

Here are your options and some more: https://www.pentaxforums.com/forums/camera-studio-accessories/43215-pentax-p-...omparison.html

[Jewelltrail]

GerryL: I have read somewhere (no longer sure exactly) that all Pentax flash would work on new Pentax DSLRs (not fry the electronics), albeit not dedicated (TTL vs P-TTL).
Don't take my word for it though.
The best way is to test the trigger voltage of the flash in question.

Thank you very much for all of your help. It turns out you are right; the flash is safe for use on Pentax DSLRs. I almost never use flash and only have this one because it was given to me. It is nothing special, but is better than the on-board flash. I thought I would spend some time with this, practicing, then move on to better stuff if I feel it is necessary.

[ChrisC]

Hi
I have a number of flash guns and have been researching if they are useable with the pentax200d - I came across this site which has some very helpful information

Photo Strobe Trigger Voltages

Wasn't able to check an old Albinon - M550T-Zoom but there are lots and lots listed !!

[Jewelltrail]

Chris, thank you for the help here.

[spystyle]

I have read at our forum that some flash mechanisms can destroy the electronics in our Pentax DSLRs. This has inspired a specific question for me:

Does anyone know if the Pentax AF160Sa is safe to operate with the K20d?

I stumbled across this thread from Google.

I have the AF160SA flash, it's a cute little flash.

It works TTL on my K20d, the only caveat is - it always fires. Even in super bright sunny light - so I take it off when I don't want it to fire.

I am unsure if it's even stronger than the on-board flash LOL

I tried it for fun, and was surprised it worked properly.

I'll do more detailed tests if requested, but for now I think I was in Tv mode @ 1/60, "auto ISO", and that mode makes aperture "auto". 18-55mm kit lens.

I think the flash always fires at full power, but adjusts the lens' aperture to get the correct exposure. If this is true it can only work TTL on modes that make the aperture "auto", like P, Tv, Auto, and similar.

I've also used it as a manual flash on several cameras, it's a cute little flash but lacks the ability to "bounce" or adjust power.

So for manual work I'd prefer to use the $40 YN460 strobist flash

The AF160SA flash has a little "eye" too, I guess that's called a thryristor circuit. That eye may be measuring the light ?

So the AF160SA may be an exception to the rule, it works on the K20d as TTL

OK have fun!
Craig

[Lowell Goudge]

I stumbled across this thread from Google.

I have the AF160SA flash, it's a cute little flash.

It works TTL on my K20d, the only caveat is - it always fires. Even in super bright sunny light - so I take it off when I don't want it to fire.

I am unsure if it's even stronger than the on-board flash LOL

I tried it for fun, and was surprised it worked properly.

I'll do more detailed tests if requested, but for now I think I was in Tv mode @ 1/60, "auto ISO", and that mode makes aperture "auto". 18-55mm kit lens.

I think the flash always fires at full power, but adjusts the lens' aperture to get the correct exposure. If this is true it can only work TTL on modes that make the aperture "auto", like P, Tv, Auto, and similar.

I've also used it as a manual flash on several cameras, it's a cute little flash but lacks the ability to "bounce" or adjust power.

So for manual work I'd prefer to use the $40 YN460 strobist flash

The AF160SA flash has a little "eye" too, I guess that's called a thryristor circuit. That eye may be measuring the light ?

So the AF160SA may be an exception to the rule, it works on the K20d as TTL

OK have fun!
Craig

Are you sure about this????

It implies that the camera sets the aperture but that is impossible, think about it for a moment.

The flash cant do any of the P-ttl functions to fire a preflash. therefore the camera does not know how much light will come back through the lens, therefore it simply cant know what aperture to set, because the light coming back through the lens is a function of subject distance, which it simply can't know. and changing aperture during exposure is simply not done.

true, the flash always fires at full power, and also true, the flash is about the same power as the body flash. the number in AF160 i.e. the 160 part, means GN=16. Most body flashes are somewhere between GN11 and GN13 so yes it is very close in power

[spystyle]

Well I just took several snap shots with the flash and they were all correctly exposed.

In one room all were at f/16, in another room they were at f/11

Here is what I used :

K200d (Tv mode with ISO set to auto, that means auto aperture and auto ISO)

FA 28-80mm (this is an auto aperture lens, as opposed to a manual lens)

AF160Sa set to "program"

I tell you it works TTL like this

Let's see other combinations ...

P mode with auto ISO
P mode with manual ISO
Sv mode
Tv mode with auto ISO
Tv mode with manual ISO
AUTO PICT with auto ISO
portrait mode with auto ISO
macro mode with auto ISO
sport mode with auto ISO
night portrait with auto ISO

It seems the trick is, having an "auto aperture" and "auto ISO". Also the flash set to "program".

So, this flash is some kind of TTL on k200d and k20d, with those settings.

But "direct flash" sucks compared to "bounce flash", so I don't think it's a big deal. Such unflattering light, like headlights, but in certain situations it's OK.

OK, have fun!
Craig

[Lowell Goudge]

Note with a GN of 16 at ISO 100 and a shooting aperture of F11 to F16 this is probably all the foash could do, what set the aperture to 16

[spystyle]

The ISO's were all over, higher than 100

[demp10]

The AF160Sa along with the AF200Sa (Pentax provides the same manual for both on their support site) are not TTL flashes and they will not work as such.

The AF200Sa has a single Auto mode that is F4 @ 100 ISO and cover a distance from 0.8 - 5 m. I am not sure about the AF160Sa but it should be similar just covering a shorter distance since it has less output power.

Like all Pentax flashes with the additional contacts (beyond the center pin that fires the flash) they can signal the camera when they are charged and also indicate their auto f-stop if at that mode. If the camera is in certain modes, it uses these signals to set both the sync speed and the f-stop. The flash has no way to communicate ISO information. If the flash allows to select an ISO value, then the Auto F-stops are modified accordingly to compensate for the new value.

TTL mode implies that the flash fires, the camera measures the light that reaches the sensor and when enough light has accumulated to satisfy the exposure, it signals the flash to turn off.

P-TTL does almost the same, using a pre-flash in low power to determine the needed light for correct exposure and then fires the flash for the duration needed.

Auto flash relies on a sensor on the flash itself to measure the exposure (like in TTL mode) and as long the camera and lens are set for the same exposure parameters as the flash everything works fine.

Auto flash, when it is used within its limitations, is a very usefully mode and works surprisingly well.

[spystyle]

Oh thanks, the term I was looking for is "auto flash", the flash has a little eye

And there are 3 contacts on the bottom, a center pin and two others.

Thanks for the info
Craig