[Atlantafine]

I have a K100 and would like to add a flash. However, I have never used one before and have some questions:

1. I normally use my camera for family photos.

2. What am I looking for in a flash?

3. Could you suggest some flashes? I dont need a $500 flash. Anything between $100 - $300 would be about right.

4. Do you know anything about the af-500 flash? I have seen this one advertised for $20?!?

5. Does swivel matter? I am assuming most flashes move up and down for bounce, so when the term "swivel" is used, it is referring to the ability to turn left and right.

6. Is recycle time important?

7. What does "54 at iso 100" mean? I know what the "iso 100" part means, but what does the "54" refer to? Also, my camera starts at iso 200, so how does this translate?

8. What does "ttl" and P-ttl" mean? What does it mean specifically in response to the K100?

9. I've seen some forum discussions where people say they can only use their flash in manual or automatic. Does the flash connect to the camera where I cant use automatic focus? Do I only get to use manual focus?

10. Do you know of any websites or articles that discuss different flashes and the terms I have asked about?

11. Would you only recommend Pentax flashes with my K100 or would you suggest any other brands?

Thank you so much.

[Ash]

Wow, lots of questions, but you've probably come to the right place with them...

Firstly, I'm close to being in your situation in that I have a K100D and mostly use it for family shots, but I occasionally do small paid jobs too. The in-camera flash is handy but doesn't produce very flattering shots. So in your case, especially if you're not doing paid work with your camera, a P-TTL flash (ie. the more expensive flash units that automatically calculate required flash intensity for the settings on your K100D using pre-flash exposure metering technology) would be more a convenience than a necessity.

Having said that, the prices of third party P-TTL flashes are going down and are within your budget, but as discussed on many other threads, are generally not as good as the original Pentax P-TTLs. The K100D cannot utilise the TTL function of a TTL flash, which doesn't use pre-flash to calculate the required settings. Other more experienced people on this forum would be able to explain these concepts better, though - I'm definitely no expert on flash technology.

But what I can comment on is an alternative setup that I've been happy with:
Having a good auto flash unit (which does not communicate with the camera, but uses a light detector to calculate how much flash it should discharge for a pre-set aperture and distance) and switch your K100D to M mode to enter in the aperture and shutter speed (bear in mind, the fastest shutter speed you can have is 1/160). Then shoot and check out the histogram. By the way, auto doesn't refer to auto focus, and manual just means the flash unit throws off a consistent amount of light each time (for many units, that's just full power, but some units can have 1/2 or 1/4 strength flashes).

That's quite simplistic, but I could go on for much longer on marrying flash settings with the camera settings for a good exposure. It all depends on what you're shooting and where you're shooting it. IMO, a flash with tilt and swivel is a must - there have been many occasions I've used my swivel flash and would not have had the results I wanted without it. But using an auto flash with the K100D takes practice as well as the knowledge of flash fall-off, bounce angles and all that jazz.

You may have to do a little research as to the meanings of guide number and ISO sensitivity. They are as important as aperture and shutter speed in flash photography. Basically, in the words of a non-pro, guide number tells you how powerful the flash unit is at a particular ISO - the higher the number, the more powerful the flash, but be sure to compare numbers using the same ISO and units of guide number (feet/metres). At ISO 200, the guide number will be about 1.4 times more than that at ISO 100. Check out how to calculate and use guide number from a good flash tutorial, as well as bounce flash techniques - it's a very good skill to develop.

This is a basic website on bounce flash:
Lighting tip - 4 ways to bounce a flash | DIYPhotography.net
This is another site on general flash photography:
Flash Photography Made Simple
Here is a comprehensive series of flash photography tutorials, focussed on Canon cameras but is very informative:
Flash Photography with Canon EOS Cameras - Part I.

I'm sure there are many others, but these should help out a little...

I've said enough and let others comment and answer your other questions...
Cheers.

[aerodave]

Here's my stab at your questions. This is just one person's opinions, so take them with the proverbial grain of salt.

I have a K100 and would like to add a flash. However, I have never used one before and have some questions:

1. I normally use my camera for family photos.

2. What am I looking for in a flash?

IMO, the only critical feature in a flash for use in indoor family shots is abiltiy to bounce. Swivel is interesting, but it's far easier to live without than bounce. P-TTL mode is also nice so you can shoot quickly without thinking too much. (More details on both these things below)

3. Could you suggest some flashes? I dont need a $500 flash. Anything between $100 - $300 would be about right.

A Pentax AF-360FGZ is always a good departure point. If swivel and extra power are critical to you, and you understand why, go up to the AF-540FGZ. I can't speak for other brands of flash, like Sigma.

4. Do you know anything about the af-500 flash? I have seen this one advertised for $20?!?

I don't know anything about it, but I'm guessing it won't work in P-TTL mode with your K100D. The only Pentax models that do are the aformentioned 360 and 540.

5. Does swivel matter? I am assuming most flashes move up and down for bounce, so when the term "swivel" is used, it is referring to the ability to turn left and right.

Swivel is the ability to turn left and right. It has two obvious applications: (1) bouncing off a wall for soft side light (or when no celing is present) and (2) bouncing off the ceiling when holding the camera in portrait orientation. I don't have it, and I don't usually wish I had it. The extra cost and bulk of the 540 isn't worth it to me.

6. Is recycle time important?

That, obviously, depends on how much you think you need to shoot rapid-fire. I don't, generally, so I don't really pay much attention to recycle time. Word is that NiMH batteries offer the quicket recycle times, although lithiums give you more shots.

7. What does "54 at iso 100" mean? I know what the "iso 100" part means, but what does the "54" refer to? Also, my camera starts at iso 200, so how does this translate?

The 54 in that case is the guide number. It ought to have units attached to it, because it's important to know if the guide number is given in feet or meters. It's basically a standard way of rating the power of a flash. Bigger numbers mean more power. The guide number, divided by the aperture you want to use, gives you the distance the flash is effective. A guide number of 54 meters (@ ISO 100) used at an f-stop of 8 would mean it's effective up to 54m / 8 = 6.75m.

Using a higher ISO makes more your camera more sensitive to light, meaning the same flash brightness can be used farther away. At ISO 200, you're twice as sensitive to light, so you can move to a distance that allows half as much light to reach the camera and get the same exposure. That's not twice as far away, it's actually 1.41 times as far, because light falls of with the square of distance. So in the example above, using ISO 200 lets you get up to 9.5 meters away at the same f-stop. You don't have to do these calculations, the flash unit will show you graphically what it's effective distance is when you use P-TTL mode.

8. What does "ttl" and P-ttl" mean? What does it mean specifically in response to the K100?

TTL means "through the lens" and it's signifies a metering system where the camera reads the flash's light bouncing off the subject and adjusts the power of the flash or exposure in the camera automatically. P-TTL is a particular system used by Pentax that gives a pre-flash a split second before exposure so that the camera can guage the amount of light necessary. It's good because you can shoot without thinking too hard, but it's not foolproof. There are times when using "Automatic" or "Manual" mode are more appropriate. Automatic isn't the same as P-TTL. Automatic means the flash unit itself uses the amount of light to adjust its own output. Manual means you figure out for yourself how much light to use and tell the flash to fire at full power or some fraction thereof.

9. I've seen some forum discussions where people say they can only use their flash in manual or automatic. Does the flash connect to the camera where I cant use automatic focus? Do I only get to use manual focus?

As above, these are just flash modes. They have nothing to do with focus. They are two of the three basic modes you have at your disposal to ensure you put the right amount of flash on the subject. P-TTL: the camera decides how bright. Automatic: the flash unit decides how bright. Manual: you decide how bright.

10. Do you know of any websites or articles that discuss different flashes and the terms I have asked about?

One great place to start to get an appreciation for lighting is the Strobist website. It deals mostly with off-camera flash, something I've recently become very interested in. You don't need to start triggering your flash remotely right away, but you may one day come to the realization that it's awesome. But even if not, Strobist and its related message board are a great resource for people who want to control lighting to take better pictures. Click on "Lighting 101" on the main page for a series of articles on how to make light your friend. Again, don't focus too much on the off-camera aspect just yet, but be aware that it exists and is powerful.

11. Would you only recommend Pentax flashes with my K100 or would you suggest any other brands?

I'm not normally one to be a brand snob. But when I chose a flash, I saw no reason to stray from Pentax. They're one of a very limited set of options to get P-TTL mode, and you know for a fact that you won't have compatibility issues. But definitely get more input about this very opinion-heavy topic.