[iht]

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Hi everybody,

I'm a complete newbie who just bought a used Pentax *ist DS from a great seller on this forum.

I've been using it with the only lens I have - the Super Takumar 50mm 1.4, which is a fully manual M42 lens.

All is well, except for the built-in flash, which always fires at maximum. This seems to be a bahaviour that is well documented in this forum, so I take it this means I need an external flash.

Requirements: I've never used one before, so I'd prefer it be easy to use, i.e. in auto mode and so on. I just need it for indoor shots of people in darker rooms and occasionally in churches with high ceilings, and maybe flash-fill in brighter conditions. I don't really know... And yes, it has to be cheap, by that I mean under AUS$50 (or US$35 or so). I heard that having a swivel would be nice, but really, I don't know, maybe one with a vertical tilt would suffice?

And no, I still don't quite get all the jargons like TTL, P-TTL...

I'm from Sydney, Australia. I saw a listing on eBay (it's a AF220T):
PENTAX AF220T TTL Compatible Flash. - eBay, Flashes, Photographic Accessories, Cameras. (end time 07-Jun-09 19:44:01 AEST)

Your help would be most appreciated. Thanks!!

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Last edited by iht; 05-31-2009 at 06:41 PM.

[Just1MoreDave]

Quick flash type rundown:
Completely manual - you set the power yourself.
"A" Flash (flash has a sensor to control light output) - Usually has at least a couple of automatic ranges and a full power mode at minimum
TTL flash - measures the light coming back Through The Lens, so it is better at getting the exact light to match, easier to use a zoom or different aperture settings.
P-TTL flash - fires a short preflash, measures light from that and decides how powerful the real flash should be. More expensive because each flash needs extra power for the preflash.

The only way you can get any sort of automatic flash with an M42 lens is to use a flash with its own sensor. Your camera can use TTL or P-TTL flashes if you get a KA-mount or newer lens. With just that 50mm lens, you can go with any reasonably powerful "A" flash, something powered by 4 AA batteries. You'll need a little more power because your lens is slightly telephoto.

Probably there are hundreds of potential "A" flashes. You need to be careful of the trigger voltage, which shouldn't be very high. Pentax is vague about the exact number but says all Pentax flashes are safe. The Pentax flashes I've tested are around 6 volts. A tilting, swiveling or zoom head will limit your choices somewhat. You might find something anywhere that sells used camera equipment.

Among the Pentax flashes, the AF280T is worth looking for. It bounces and swivels, works as an "A" flash and also in TTL if you get a compatible lens. The AF240Z does everything you want except swivel, and it has a zoom head to work with telephoto or wide-angle lenses, but no TTL. The AF200T doesn't bounce or swivel, has TTL and "A" flash, and has three manual power settings. There are a few others but those are my top three recommendations.

The AF220T you linked to does not have its own sensor, so it only works as a TTL flash, not with your lens. I use the AF500FTZ, which has a lot of features and power except for any "A" flash ability.

Sorting through third-party flashes might be worth your trouble. I have an Achiever 260T with a bounce/zoom head and three power ranges. Most of these flashes will sell for little money but should work for you.

[Mike Cash]

Among the Pentax flashes, the AF280T is worth looking for. It bounces and swivels, works as an "A" flash and also in TTL if you get a compatible lens.

A hearty "Amen, brother" to the AF280T.

The AF200T doesn't bounce or swivel, has TTL and "A" flash, and has three manual power settings.

Four manual power settings (full, 1/2, 1/4, and 1/8). Compact, versatile, and a most handy tool for off-camera flash.

[AndrewG NY]

Another recommendation for the AF280T. Have used this some on my similar *ist DS2. You probably already know that these are sub-optimal on newer bodies since Pentax dropped TTL support on the K*D series, only P-TTL is supported--so if you want to use a flash like this on the newer bodies you need to use manual or auto-flash; so these are good features to have if you think you might want to use the flash on a newer body later; makes the flash more versatile.

[iht]

Thanks guys. Sounds like the AF-280T is the way to go for the *ist DS. Very helpful info. I'll see if I can find one locally. It seems they go for about US$50 or so.

I'm intrigued by the "Auto" mode re how it would work with a manual M42 lens. I take it the flash sensor can sense distance and brightness of the subject irrespective of camera settings.
- How would the flash calculate what it thinks is the correct exposure, when it doesn't know my aperture and so on?
- Have you had experience in working a manual lens with the AF-280T?
- Do I need to start learning about guide numbers and so on?

And general AF-280T/flash questions:
- How does flash work with different focal lengths? I saw on eBay wide-angel/tele "converters" for the AF-280T. Are they required?
- In general, what's the difference between a very expensive flash, and say, the AF-280T? Is an expensive flash brighter, or is it more versatile in some way?

Sorry if some of the questions are a bit basic. It just seems flash is in a whole world of its own and it's a bit intimidating to look into.

[iht]

Just resurrecting this thread here:

I got my AF-280T at AUS$58 from xbay about a month ago. It's a flexible flash!

I put my flash on the *ist DS, and set the ISO to 200, stopped down on the Takumar 50mm, set the flash to AUTO GREEN mode....it was WAY overexposed for a subject about 3 metres away. I was bouncing the flash off the ceiling about 3m high, and compensate flash exposure by +1ev.

I then flicked the flash into TTL just to see what would happen. From the previous replies I take it TTL is not supposed to be compatible with a M42 lens. Behold, the photo was correctly exposed! I've been using TTL mode ever since with subjects within 5-6 metres, and it's working well.

Any idea why?

[iht]

And yes, I was shooting in Av, but I think the shutter speed is always locked at 180, which I'm guessing is the sync speed of the flash.

[iht]

Oh dear...in bad form today....forgot to mention I stopped the lens down to f5.6 or so, or at least f4.

[pbo]

Eh... I might be wrong here, so someone correct me if I say smth stupid.

You were using a manual lens, so probably your camera *still* fired at full power and not TTL - this is what I'm not sure about, though.
I'm thinking you probably just got lucky with aperture. If you fired at subjects at a constant 5~6 meters away - then I can pretty confidently say you got lucky with aperture try something closer or farther - and you'll get over/under exposed shots.

Now, about auto mode - though it's been for a month, nobody answered your question.
The flash itself has no idea about what's going on in the camera. On auto, it TELLS YOU what aperture to set for a certain subject certain number of feet away. You should be able to match the distance to the subject with an aperture needed by reading the scale on the back of the flash.

And yeah, 180 is camera's sync speed.

Hope it helps,
Bo.

[Just1MoreDave]

Eh... I might be wrong here, so someone correct me if I say smth stupid.

You were using a manual lens, so probably your camera *still* fired at full power and not TTL - this is what I'm not sure about, though.
I'm thinking you probably just got lucky with aperture. If you fired at subjects at a constant 5~6 meters away - then I can pretty confidently say you got lucky with aperture try something closer or farther - and you'll get over/under exposed shots.

I think there was some luck and some help from the flash involved. I used my *ist DS, a Takumar 50mm f1.4 lens, and my TTL-only AF500FTZ at about the same distance. I took shots at every stop from f1.4 to f16 in Av mode with the lens set on manual aperture, and the camera set the shutter speed at 1/180 sec. The flash adjusted its power each time, very low for f1.4 and high for f16. Exposures were too bright at f1.4 by maybe 1.5 stops and too dark at f16 by maybe 2 stops. Exposures were not correct except in that f4-5.6 range, the luck part. If I get closer, the exposures are better over a wider aperture range. The combination appears to almost work, but missing some element needed for full automation. The Auto flash mode should be more automatic than TTL. I have no idea why it's not.

And general AF-280T/flash questions:
- How does flash work with different focal lengths? I saw on eBay wide-angel/tele "converters" for the AF-280T. Are they required?
- In general, what's the difference between a very expensive flash, and say, the AF-280T? Is an expensive flash brighter, or is it more versatile in some way?

Sorry if some of the questions are a bit basic. It just seems flash is in a whole world of its own and it's a bit intimidating to look into.

Converters either spread out or concentrate the flash beam to match the field of view of the lens. Older flashes are designed for a "normal" lens (around 50mm) on film. On digital, your lens is more like a short telephoto, so a telephoto converter might work for you, concentrating the beam to only cover what your lens sees.

More expensive flashes can have a dizzying array of cool features. For example, my AF500FTZ has a motorized zoom that gets focal length information from the camera, and zooms along with the lens. That automatically does the same thing as those converters. I can take it off the camera and set it to fire at the same time as the onboard flash. It can fire the flash just as the shutter is closing instead of just when it opens, for interesting effects at slow shutter speeds. The current expensive Pentax flashes have many other features. A lot of them require a modern lens to work. Documentation of these features and how they work with each camera is thin.

[newarts]

There's a few free ways to use your on-camera flash- here's two:

1), The guide number for your on-board flash is 15.6 @ ISO200. Here's how you use it to set up a photo:

Set the camera to ISO 200

Estimate distance to the subject (meters or yards or waist-heights) then set the f-stop=15.6/distance. Take the photo.

Example: subject is seated about 4 waist-heights away. Set the f-stop to 4 (15.6/4 is about 4) and take the photo.

2). Fool your camera into thinking the lens is an A type lens - this involves a slight modification of the camera mount - then the flash will work automatically with a manual lens.

Dave

PS if it is easier for you to estimate distances in man-heights, just change the guide number to about 8. So at ISO 200, a subject 2 man-heights away needs about f-4. This is fun actually, imagining these guys lying head to toe from you to the subject.

[spystyle]

...2). Fool your camera into thinking the lens is an A type lens - this involves a slight modification of the camera mount - then the flash will work automatically with a manual lens...

Can you describe this procedure?