Flash and Exposure Modes

Depending on the exposure mode you have selected, your choices of flash mode change.

In this article we'll briefly discuss the flash modes available for each of the exposure modes.

Mode Dial

The K10D's mode dial is a little different than the rest of the Pentax DSLR line and probably other brands of DSLRs also. For those that are looking for a point and shoot option you have 2 modes to choose from.

Before we talk about those 2 modes lets talk about the program line as that setting is the basis on how the camera will compensate for exposure changes.

PROGRAM LINE (pg 145 user manual)
Located in the main menu under custom settings, the program line is used to tell the camera what exposure setting in the camera you want to prioritize. What the camera does then (if it can) is to hold the program line setting and adjust the other exposure values to compensate.

Here's an example. Say you want maximum depth of field in your photos, then set the program line to depth of field. Now when the camera goes to set the exposure it will try to set the maximum aperture it can with the available light.

(edit 24 Nov 2007 11:14am) I tried the DoF setting in program mode and apparently it works opposite of what I had envisioned. It seems to keep the aperture set to minimum. I will experiment more and let you know in a later post. (edit)

The other settings are for high speed shutter priority and modulation transfer function (MTF).

High speed shutter is just that, the camera tries to give you the fastest shutter speed possible under the lighting conditions.

MTF needs a little explaining and is only available for certain (newer) lenses. Modulation transfer function is used to find the sweet spot using the data (focus distance/focal length/aperture) obtained from the lens. I assume the camera has a built in table of this data and this setting will try to set the lens to the optimum aperture for the focal length and focus distance. Those who are not so happy with the quality of the kit lens might try this program line setting.

So the program line setting will depend on what you are shooting, sports - high speed, macro - DoF, or MTF - best quality from the lens.

GREEN MODE
The green mode automatically adjusts the aperture and shutter speed according to the program line setting. The photographer has no control as this feature is totally automatic and bases it's settings purely on the program line. You can't even do exposure compensation (EV) in green mode. But that's fine if you just want to shoot pictures and not worry about the camera settings, your typical point and shoot scenario. This mode is not available with manual lenses. Although I managed to get my camera to fire the exposure was underexposed.

P or HYPER PROGRAM MODE
This mode gives the photographer a little more freedom with exposure settings. While in P mode you can adjust exposure compensation with the front dial while holding the +/- button, shutter speed with the front dial, and aperture with the rear dial. When you change one setting the others, depending on program line, will adjust to compensate. This mode is also not available on manual lenses. Although I managed to get my camera to fire the exposure was underexposed.

Sv or SENSITIVITY (ISO) PRIORITY
Sv mode is another fairly automatic mode that limits the photographers ability to make adjustments. It does not use the program line to determine the computed settings. The photographer is only allowed to adjust the exposure compensation EV setting. The way this mode works is the photographer sets the ISO level and the camera sets the shutter speed and aperture to the proper exposure. This mode is also not available on manual lenses. Although I managed to get my camera to fire the exposure was underexposed.

Tv SHUTTER PRIORITY
Tv mode works like on any other DSLR. The photographer sets the shutter speed manually and the camera adjusts aperture and ISO (if on auto ISO mode) to the correct exposure. This mode is also not available on manual lenses. Although I managed to get my camera to fire the exposure was underexposed.

Av APERTURE PRIORITY
Av mode also works like any other DSLR. The photographer adjusts the aperture with the rear dial and the camera adjusts the shutter speed and ISO (if in auto ISO mode) to the correct exposure. This mode is also not available on manual lenses. Although I managed to get my camera to fire the exposure was underexposed.

TAv SHUTTER AND APERTURE PRIORITY
The TAv mode is a combination of the Tv and Av modes. The photographer adjusts the shutter speed and the aperture with the front and rear dials and the camera adjusts the ISO to the correct exposure. This is nice to have the camera do automatically as many advanced photographer did this manually before and had to go a few levels deep in the menus to change it each time. This mode is also not available on manual lenses. Although I managed to get my camera to fire the exposure was underexposed.

M MANUAL MODE
Manual mode is just that. The photographer sets the shutter and aperture and ISO to what they think is appropriate. The camera will let you know if the exposure settings are incorrect and by how much. If you have a manual lens, the little green dot button just to the left of the shutter button will set the shutter speed according to the meter reading after the aperture is stopped down. When you press it you will here a brief swish-swish sound of the aperture blade moving. This is the mode to use on all manual lenses.

B BULB MODE
Bulb mode is used when taking photos of an undetermined amount of time or a time longer than the cameras minimum shutter speed. It is used mainly for astrophotography, fireworks, and any long period of time for light painting but has many other uses only limited by the photographers imagination. This mode is compatible with manual lenses.

X X SYNC
X Sync mode is used to set the camera to a shutter speed of 1/180, the K10D's maximum flash sync speed. When a non compatible/non high speed flash is connected to the camera the shutter speed will not be able to be set higher than 1/180. Personally I think this is a severe limitation of the K10D and severely limits the use of flash when trying to over power the sun in bright daylight situations. So far this is the only major gripe I have with the K10D. If I find a way to bypass this through the camera's debug mode I will pass that info on.

USER
The user mode is recalls settings from memory that the photographer has stored. There is only one memory location so only one set can be stored at a time. These settings can be adjusted on the fly while in user mode.

Next Article

Metering Exposure.

Youth Soccer Team

Taken at 75mm. The on camera flash was fired in hopes it would trigger a slave flash that was about 45deg off the goal. But the sun was too powerful and the slave did not pick up the signals from the camera so it didn't fire. The on camera flash did not add much to the photo as I was quite far away from the goal at 75mm.

The saving grace in this photo was the K10Ds multi-segment metering mode that works well in back lit situations like this.

---

The first basic function of any camera is to figure out how the camera meters the light in a given scene.

The K10D like most modern cameras uses a built in light meter to calculate the amount of light and make internal adjustments to the exposure settings to obtain the best exposure.

Digital sensors have the ability to capture a wider range of light than negative and slide films, but they still do not come close to the range of the human eye. This is obvious when a photographer tries to shoot a scene that is light by bright noon sun and has many deep shadows. What the photographer sees and what the camera sees are completely different. The camera sees pure white in the brightest areas and pure black in the deepest shadows where the eye can see shading and details in both the bright and shadow areas.

It is the photographer's job to try to figure out where to set the midpoint so the camera can capture the optimum range of light. The camera offers a few tools to help communicate this data. Inside the K10D are 16 zones that can measure light levels. There are 3 metering methods available (pg 142).

MULTI-SEGMENTED METERING
The multi-segmented method relies heavily on the camera deciding what the light levels are and the photographer is left out of the metering loop. This can be a good thing or a bad thing depending on the skill of the photographer.

This metering method reads the light level in each of the K10D's 16 zones and adjusts the brightness in each zone. This is great for point and shoot where you want a very balanced even lighting with highlights and shadows both exposed to the best of the camera's ability. However, it is not the magical metering method it sounds to be. For one there might be some zones where there is both bright light and dark shadow. The camera then tries to find a happy medium and the shadows will be lowered if the brights are lowered and vice versa. However the zone next to it might be in complete shadow or complete bright and it will be adjusted differently and as a result the 2 adjacent zones will not be exposed the same. The result will be either a photo with a very compressed tonal range or a photo with a patchy tonal range. The former is what happens when we post process an image with a wide tonal range anyway, the latter would look more like a bad post process dodge/burn job. However, this mode is good for back light scenes if you want to see detail in the silhouette.

CENTER-WEIGHTED METERING
This mode also measures the entire screen but more emphasis is placed in the center of the screen. If you look at page 143 in the users manual you can see the graph that represents how the meter evaluates the scene. As the book says this is not to be used for back light scenes as there will be a substantial amount of silhouetting.

SPOT METERING
This mode is the one the photographer uses to decide what they want the exposure to be. You point the center of the viewfinder at the area in the scene that you want to meter and press the exposure lock button to lock in that reading.

METER OPERATING TIME
Meter operating time sets the length that the meter will hold the exposure value before reseting it. This is a handy feature as you will find certain scenes that take longer to compose and you want the metered exposure to last a little longer before it resets.

HISTOGRAM
One other thing that should be discussed in the metering section is the camera's histogram. The histogram is a graphical representative of the quantity of each tonal range. The left edge of the graph represents pure black and the right edge of the graph represents pure white. The area in between from left to right is a gradual increase from pure black to pure white. What the histogram will convey to the photographer is the amount of underexposed (pure black) and the amount of over exposed (pure white). There is no exact correct histogram shape and they will vary from scene to scene or could be the exact same shape for 2 very different scenes that have the same quantity of tonal values. For an average lit scene with shadows and bright spots there should be readings all the way across the histogram, but if the histogram shows all the data bunched up to one end or the other then it is indicating an improperly exposed photo. The experienced photographer looks at the histogram to judge exposure and the image to judge composition. This is called chimping. You may only have to chimp a few times to get the exposure you are after then just take photos until the scene changes and you chimp again.

Next Article

New K10D

I've had my new K10D for just under a week now. I have only shot one event with it but that was nearly 500 photos. It was a youth soccer game at the local Y. I suspect my Tamron 70-300 4.0-5.6LD Marco lens is not the best suited for action sports but it did a decent job and I ended up with some keepers.

I took some quick and dirty (literally) product shots of the camera here.

It's going to take some getting used to with the different mode dial settings, but from what I've seen so far I really like it. It has some neat features that I will discuss over the next few weeks.

Next Article

Why This Blog

Understanding the Pentax K10D

When I got into digital photography I opted to invest in Pentax because of the quality/price performance of their lenses. That and the fact you could use any K-mount or screw mount (with adapter) lens ever made. To me it was a no-brainer. So I started with a Pentax *ist DL and have loved the camera from day one.

I recently upgraded to the K10D for the larger sensor size, image stabilization, and the PRIME graphics engine that provides the ability to shoot continuously in jpg mode.

In this past year my only gripe with either DL or K10D (and the AF540GZ flash) is with the user manuals. They are not written very well nor in enough detail. The flash manuals are outdated since they don’t include any information on the K10D and there are several errors I have encountered in the manuals. As a result I see many Pentax owners online asking the same questions and complaining that the manuals are confusing.

I searched online for any help I could find and what help I found was scattered in forums and not logically ordered. I ended up with only a few book marks scattered all over the internet.

Another of my hobbies is Unix/Linux and my operating system of choice is FreeBSD. One thing I like about searching for FreeBSD help online is I found the majority of the information I was looking for at one or two websites.

I decided since I have pillaged many a website for information over my lifetime that is was time I gave a little something back. So here it is, a single website repository full of information about the Pentax K10D.

Please leave comments on how I can make the blog better. If you have any questions just ask and I will try to answer, or some other kind reader may answer.

Next Article