Ricoh Flash 

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The flash on the R series is often criticised, but if used as the manual says, it does provide decent results in the range that the manual states.
Flash Issues (Under Construction, needs serious revision)

Beginning of re-write on flash........
With many people having problems with Ricoh flash it's time to re-state the rules... Use Auto ISO and stay within the specified distance. That's all.
No, wait a bit, I'll expand on that and list all the factors that matter....

The problems with flash stem from  one or more of the following situations.....
By not using Auto ISO
By not staying within the range stated in the manual
By not obtaining accurate focus - very important!
By not having exposure compensation at 0 or maybe -0.3 EV
By not removing the finger in front of the flash

Now for some science.
It appears that the Auto ISO is set by the distance to the subject but I need to do more careful tests there. If setting the R4 (in my test case that follows) at 1 metre distance the Auto ISO settled at 383 (with one minor variation to 400) and the aperture stayed at f/4.7 for all shots in the next test.

The test was to see how the use of the EV compensation had an effect on flash output. The manual states it nowhere, but using the plus or minus EV can make flash successful if you are prepared to take a bit of time setting up and testing for the shot in question. Mainly this is of  use for those people who (mistakenly) think it's easier to use a manual ISO setting for flash.

Here's the page of thumbnails that proves the flash variation with EV compensation....
thumbnails flash test
R4000140 at 12.3mm focal length with Auto ISO = 383, f/4.7, distance 1m, compensation -2.0 EV
R4000141 at 12.3mm focal length with Auto ISO = 383, f/4.7, distance 1m, compensation -1.0 EV
R4000142 at 12.3mm focal length with Auto ISO = 383, f/4.7, distance 1m, compensation 0 EV
R4000143 at 12.3mm focal length with Auto ISO = 383, f/4.7, distance 1m, compensation +1.0 EV
R4000144 at 12.3mm focal length with Auto ISO = 400, f/4.7, distance 1m, compensation +2.0 EV
Camera set to Colour = Neutral as that is the normal way I use it for accurate colours.
If the images don't show much, then the histograms certainly shows the exposure variation caused by the flash at various compensation levels.

I used FastStone Viewer to make the histograms, then copied the screens one by one to Paint Shop Pro, cropped and then saved as gif files, and then displayed it all in FastStone Viewer and re-shuffled the images to get them side by side. Then copied the screen to Paint Shop Pro, cropped and made this gif. Easy.

More.... (and more to be done to prove what's happening)
Tested the R4 flash at various distances and focal lengths and it appears that with Auto ISO the ISO jumps to 383 or 400 very readily, it's only when very close to the subject that ISO 125 or similar may appear. That plus the limited flash "TTL" adjustment range means that the distance focused is critical. Only a slight mis-focus (which may not be readily apparent on the LCD) will alter the ISO and aperture chosen and may put the settings out of the range of the flash adjustable output for the real distance involved.

Whenever I had perfect focus the flash was always accurate, if I deliberately misfocused by half press on a different distance, and then recompose at the desired scene, the flash output was wrong.

Just to complicate matters, sometimes when the green focus OK brackets showed, the scene on the LCD was not in focus. That would result in a bad flash result.

So the answer to good flash is always to use Auto ISO at 0 EV compensation and make sure the focus is truly correct, also I used Flash = On all the time, I found no errors that way. Some say use Flash = Auto but my findings were that it made no difference to flash accuracy.

If you get an over-flashed image then carefully check the focus before you discard it. I never got a bad flash when the focus was correct, but always got a bad flash when the focus was wrong. Just remember to switch back to ISO 64 for those outdoor daylight shots.

Old flash writings....

On first tests my R3 gave really bad flash results. After our 3 week trip where we basically avoided using the flash, we sent it in for warranty repair and it came back working better. I'll run a few tests to see if I'm fooling myself about the settings needed to get decent results most of the time. First issue I've run across is that I need to make the LCD appearance match what the same image looks like on a properly calibrated PC monitor. I have the LCD bright to suit Aussie outdoor sun conditions, so the result may appear bad on the LCD but be quite acceptable on the PC monitor. 

Setting the LCD to lowest brightness indoors makes the LCD look more like the image really does, but of course altering the angle at which the LCD is viewed changes it from apparent dramatic under-exposure to dramatic over-exposure. In that case, use the Histogram display to get a better idea of what happened to the image.

The histogram display says it all, with thumbnail images inserted over the histograms to show the under and correct exposure........

histogram 1

The histogram above is from FastStone Viewer a nice freebie found via my software pages. This histogram shows me that the scene was badly under-exposed, a spike of gloomy and dark pixels to the left near 0 brightness, and nothing really above 192 in brightness. The exposure should have been using either a larger aperture, slower shutter speed or bigger flash. In this case above I set the camera to ISO 100 and took a room scene from about 6 feet.

And now the histogram below from the same scene taken a little later with Auto ISO (it went to ISO 322) and same distance etc, now the pixels are pushed to the right, indicating proper exposure across the available range of brightness. There's a chance that some of the small highlight areas may be a bit over-exposed because there is a small bunch of pixels crammed right against the 255 mark. But the result on the PC monitor looks much better and with less noise evident due to the better exposure, and that is despite running at a higher ISO.

histogram 2

When reviewing the images on the camera, the optional display selection of including the histogram tells me more than the picture displayed on the LCD. Even though the details of the histogram looked different compared to the computer display, the same basic under-exposure histogram was evident on the same shot. The properly exposed image had a decent histogram filled from right to left, just like above.

When I have a better set of images taken under better controlled conditions, I will show all the examples here, that is, the images, and camera histograms and PC histograms.

Here's a sample of the camera screen with a little note about the histogram seen.....

histogram 3

Meanwhile, I have been raving on in the Ricoh Talk forum at DPReview that Auto ISO is not to be trusted when using flash, but now I am starting to see that it is probably best to use Auto ISO to always get the shot first try (and check the camera histogram, rather than trust the image display), as long as you understand the distance limits of the flash/lens aperture combination. The small flash means the range is really limited. More on this later after I do more testing.

Be very aware of the flash range as stated in the Ricoh manual......

With Auto ISO and at the widest angle setting, the flash range is from 200mm to 2.4m (8 inches to 8 feet), and with the lens at the maximum telephoto setting the flash range is from 140mm to 1.8 m (5.5 inches to 6 feet). Those figures assume that the camera may be in normal or macro mode. With Auto ISO the camera may expose at anywhere from 100 to 400 ISO.

The focus range of the lens without macro at wide is 300mm (12 inches) to infinity, and at maximum telephoto is 1m (3 feet 3 inches) to infinity.

The focus range of the lens with macro at wide is 10mm (0.4 inches) to infinity, and at maximum telephoto is 140mm (5.5 inches) to infinity.


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