Flash on Nikon d50 broken, need to set up correctly

Question

Nikon D50 comes with built in flash now it's not been firing for a while and its impairing the camera's usability. I've now changed to a speed-light but seems that the two different flashes have a very different outcome on the quality of the picture. I am getting very bad grain on black sections or darker sections of my photos when using the speed-light no matter what ISO setting I have.

Is there a way to stop this or reduce the grain? As I don't want to fork out for the repairs on this camera It may be worth just buying a new camera.

Answer 1

"Grain" (really, noise) in your photo is principally determined by the ISO level. More stictly speaking,

1. by the electronic amplification applied to the electrical signal captured from the photosites in your camera's sensor
2. by the shot noise inherent given a specific photosite (sensor element) physical size and actual light level
3. by the temperature of the inside of your camera

It seems unlikely to me that the speedlight is directly causing noise; I can't think of a physical mechanism for this. It's more likely that you are seeing a higher ISO level or there are image processing differences. The second could just be different camera settings.

The first could be caused by low flash output causing your camera to push its ISO settings; this will only happen in auto-ISO mode. But since you said "no matter what ISO setting I have" I'm not certain you'd be uaing auto-ISO.

Try posting an A/B comparison pair of images if you would like more specific advice.

Answer 2

What kind of flash unit? The pop up flash on camera is pure evil. Just gaff tape it down and never use it. At ISO 200 there is no way you should be getting noise. Check your metadata and see if something is consistently the same on the bad pics. Also try shooting at ISO 200 outside in natural light as a test.

Answer 3

It may just be a case that the flash power is too high -- Have you tried dialling in some flash exposure compensation to reduce the output from the flash?

Answer 4

I would check your camera's flash settings. Usually, there are settings for the built-in flash and separate settings for other flashes. The two settings may not be the same, so matching the settings for alternative flashes to the settings of the built-in flash may help normalize your results.

It should also be noted that the built-in flash and the external flash could have different results simply due to quality and part factors. Built-in flash tends to be very cheap, where as other flashes can be of much higher quality. You may need to adjust the in-camera settings, and possibly the flash settings, to compensate for the differences to get similar results.