[emalvick]

I just found an AF-280T in excellent condition for $35 on Keh.com, and bought it as my first flash for my K10d.

I know it isn't P-TTL, and I know the TTL won't work. My question is how well does it work for people in its Auto and Manual Modes?

From what I read the auto modes work decent. If I set the camera in P-mode, the camera and flash will both adjust appropriately?

A bigger question for me is that I wanted a flash to serve as a fill flash for high contrast scenes. Is it hard to do that with the AF-280t? For instance, I have a scene that requires a 1/500 sec shot to keep from blowing out the bright areas. Can I make the flash fire in those situations?

I am not sure if I'll be receiving a manual or what with the flash and realize that even with a manual it may not be very helpful for my K10d, so I am looking for any and all suggestions or advice so that I can make the flash work decent on first try.

It doesn't help that I've never worked with an external flash before, but I couldn't afford a better P-TTL flash, and I'm usually quick at learning things anyway, so the AF-280T will be sufficient for me as I practice.

Thanks in advance for any pointers or advice.

Erik

[Ben_Edict]

It is probably the best flash gun Pentax has ever made. Extremely reliable and the Auto-mode is very good.

You cannot use it with high-speed sync, though. The shortest sync speed is the standard x-sync speed of your camera.

For fill-flash use an manual mode on the flah and simply dial in (in the flah) an ISO setting one EV higher, than you use in camera. Example: camera = ISO 200 and flash = ISO 400. That gives a nice fill, but preserves the ambient light as the main light.

Ben

[emalvick]

It is probably the best flash gun Pentax has ever made. Extremely reliable and the Auto-mode is very good.

You cannot use it with high-speed sync, though. The shortest sync speed is the standard x-sync speed of your camera.

For fill-flash use an manual mode on the flah and simply dial in (in the flah) an ISO setting one EV higher, than you use in camera. Example: camera = ISO 200 and flash = ISO 400. That gives a nice fill, but preserves the ambient light as the main light.

Ben

Thanks for that information.

... So I basically need to be sure that I have my camera set at a shutter speed at 1/180 or slower and whatever ISO gets me that shutter speed, I should set the flash one stop higher as in your example.

Now what I wonder is what affect adjusting the aperture in that case might have. I ask because being new to flash and the need for fill light (a bit naive and ignorant in the past on my part), I recently had an experience where the shutter speed of the photo at ISO 100 and f8 was 1/320 sec. That left me with a shot that was underexposed in the foreground but perfect for the remainder of the shot. With a fill flash, I would have solved the underexposure issue, but I am not sure what affect the aperture would have with regard to the flash in this application.

If I adjust the aperture in such a shot to get the shutter speed to 1/180, do I need to worry about the effectiveness of the flash that typically goes with adjusting the aperture? (again this is for fill and not a typical dark scene).

I guess I have a lot to learn. Hopefully, I'll have my flash Monday and I'll get a chance to play with it and see just how things work out. I think I also look into a book on flash photography to learn as much as possible.

Erik

[Mike Cash]

The AF280T is a very nice flash, but it doesn't have much in the way of manual power settings. Fortunately, if you want to do daylight fill and your camera has ISO 100 you can easily do it on one of the auto settings.

Here's the idea:

For a broad daylight "Sunny 16" situation at ISO 100 you're looking at a shutter speed of 1/100 at f16. If you (roughly) cut the shutter speed by one stop to the flash synch speed of 1/180 then you have to adjust the aperture open one stop to f11 to compensate. The two auto settings will give you a choice on the two auto settings of either f8 or f16 (at very close ranges) so you can choose one stop over ambient or one stop under ambient.

Adjusting the ISO slider on the flash unit has NO EFFECT on any setting whatsoever. Actual ISO adjustments must be made in the camera.

[emalvick]

Mike, thanks for that information. That is what I wanted to know. I get used to shooting in the f8 to f11 range for my lens since it gives its best performance, so I wanted to be sure that adjusting the aperture is reasonable, and I see that it is.

By the way, it has been a lot of your examples that convinced me that the AF-280T would be the way to go for my wallet and camera as a starter flash.

[Ben_Edict]

... So I basically need to be sure that I have my camera set at a shutter speed at 1/180 or slower and whatever ISO gets me that shutter speed, I should set the flash one stop higher as in your example.

O.k.: you know, that 1 aperture stop is equivalent to one step in the speed ladder. So f/8 at 1/250s leads to the same exposure as f/11 + 1/125s or f/5.6 + 1/500s etc. Now the film or sensor speed comes into the play: changing the ISO setting from 200 to 400 is exactly one f-stop faster.

Now we have three variables and the combination of these variables can lead to the same expsoure:

f/8 + 1/250 at 200 ISO leads to the same exposure as f/8 + 1/500s at 400 ISO.

This is the reason, why I suggested to simply adjust the ISO setting on the flash.

Now what I wonder is what affect adjusting the aperture in that case might have. I ask because being new to flash and the need for fill light (a bit naive and ignorant in the past on my part), I recently had an experience where the shutter speed of the photo at ISO 100 and f8 was 1/320 sec. That left me with a shot that was underexposed in the foreground but perfect for the remainder of the shot. With a fill flash, I would have solved the underexposure issue, but I am not sure what affect the aperture would have with regard to the flash in this application.

The problem with fill-flash, which you cannot high speed sync is, that the shortest exposure time is basically fixed at 1/180s. So you have two adjustement possibilities: aperture and ISO setting.

To use fill-flash successfully, you would usually adjust aperture (fixed 1/180s shutter speed) so, that the general background is exposed properly. That leaves you usually with deep shadows on the faces of people you want to portray. The trick now is, to use the flash in a way, that brightens those shadowy faces to a degree, which looks still natural. You would usually not want to make the flash light obvious or dominating.

This is the reason, why you would chosse a flash output which is app. 1 f-stop less, than a correct expsoure would require.
Now, how can we achieve such an dimmed flash output?
With a P-TTL flash, you can just dial in an -1 EV exposure correction in the camera menue. Or (depending on the flash gun you use) you can dial in this correction directly on the flash.
With an Auto (Thyristor) flash gun, you would usually just dial in an aperture 1 f-stop smaller, than you actually use in the lens. If you have set your camera lens to f/8, you would dial in f/5.6 in your Auto flash.
You could also, because ISO/aperture/shutter speed are interdendend, simply dial in the aperture of your lens and set the ISO setting 1 step higher, than you use in your camera.

In both cases (dialling in smaller f-stop or higher ISO setting), the result is the same: the flash produces an output 1 EV less, than would be required for correct expsoure - the ideal fill-flash.

Unfortunately the 280 is limited in available Auto-settings. It offers only 2 f-stops. At ISO 100 you can either use f/4 or f/8. But the 280 also has full manual output in two steps, high or low. So it might be easiest to just use the manual output and make test shot, to see, which setting works best. With a digital camera this really is easy and fast.

I hope this somewhat long explanation is readable for you. I guess my first answer was a bit short ion places, which led to Mike's post.

Ben

[emalvick]

I understand, and I understand the concepts of exposure. The new variable to me is the flash. I understand how the flash relates to aperture for the typical flash use, and you guys have cleared up how things would work with the fill flash. Obviously, I'll learn quite a bit more once I have the flash and can play with it for all instances I might use it.

The fact that the flash only has limited options will I hope be a blessing.

Just as an aside, the thing that always bothered me about flashes these days is the variety of settings they can have combined with the variety of settings you can end up with on the camera. I probably could learn them, but I was used to using a film SLR without a flash in the past and more recently the inadequate flashes that are onboard digital cameras include the one on the K10d. The fact that a simpler flash like the AF-280t could work with the K10d was enough to make me go out and get one because it basically is nothing more than a high and low option, which is all I really need at this stage of the game.

I'm sure that as time goes on I'll want more, and hopefully it will be a bit more time so that I can afford the more (or those more options get cheaper). As it is, I've gotten by for years without any decent flash, so I am sure the simple AF-280t, will be a huge improvement and a nice educational experience for me.

This forum is fantastic for learning these types of things. Thanks for the help.

[code4code5]

I also use an AF280T, handed down by my father. Indoors, I always bounce to avoid hot spots. I find that the red auto mode works about perfectly indoors and generally set the camera to 1/160 at f5.6, but I've never tried to use it for outdoor fill. I am certainly no strobist, but I am usually quite happy with the results.

When I can't bounce, I use a Lumiquest omnibounce and find that this flash has plenty of power to compensate.