Flash and digital cameras
Using external flash with digital cameras
Introduction
When I bought my first digital camera it was a very difficult decision for me. I was very insecure buying the Canon S30 or G1. The G1 has a hot shoe for attaching external flashes which was important for me because I was used to a big Metz flash for my Canon SLR. It was a good idea that I took my flash to the shop when buying the digital camera because my flash did not work with the G1. Unhappy about this I decided to buy the S30 because it is smaller and better fits in pocket.
Possibilities
If your digital camera has a hot shoe for external flashes you in general have two possibilities:
- Attach external flash on hot shoe
- Use a slave adapter triggering external flash by internal flash
Hot Shoe
When attaching a flash the following things are important otherwise it won't work (as it should):
- The flash must be compatible with the camera. Some companies provide different adapters for their flashes - either for Canon, Nikon etc. cameras.
- Your flash should support E-TTL (Canon) and maybe I-TTL (Nikon). If you already have a flash that you used with your SLR/optical camera than it will most likely only support A-TTL which may not be sufficient.
- Be careful with older strobes. They might run with a different voltage which could damage the camera.
Slave flash
A special adapter registrates the light impulse from a primary flash (camera internal flash) and in the same moment triggers a flash connected to the adapter. With such an adapter (e.g. Hama 6967) you can combine any external flash either with your digital compact camera (without hot shoe). But there are some issues:
- The flash may not get fired if the connected flash does have not only the middle contact.
- The flash may wait for more than the impulse coming through the middle contact. Metz for example used to offer different adapters for their flashes e.g. one for Canon camera models, for Nikon etc. - and a simple adapter with only middle contact (Metz Standard 301). They do not offer these any more.
- You might experience flash synchronisation problems.
- There are people saying that the digital camera produces two flashes (at least Canon PowerShot G series). A first one to get information about white-balance etc. and a second where the image is recorded. This might be true for some cameras, I do not think it is true for the Canon PowerShot S50 (after some tests). However, If your strobe supports Stroboskope flashing that you could set the flash stroboskope to get the same effect for your flash. It only takes a lot of time (and battery) for tests until you got the correct settings.
Case study
In my case I wanted my Canon S50 to work together with my Metz 40MZ-2 flash that I used with my Canon EOS 500N SLR. OK, these models are very old, but the principle remain the same.
First I buyed a Hama 6967 adapter for using my Metz flash as slave. I was told in the shop that a middle contact is required at the flash foot. The flash has a middle contact - but not only (there are some other contacts as well). Well, I ordered the adapter and then tried but nothing happened. The Metz flash was not triggered. First I thought that probably the adapter is broken but then I contacted Metz. They told me that I need another "foot" (the standard 301 "foot") for my flash (indeed they are changable and I had only the Canon adapter). After buying this adapter (this time I took my camera and flash to Metz because I wanted to be sure that it works before buying the adapter) the flash fired.
However, the pictures were very dark. Although I have seen that the flash fired, it didn't seem on the picture. I began to read some articles on the web (which I usually do before, but in this case I hadn't) and found some people struggling with the same problem. If I had read these articles before I wouldn't have bought these adapters and tried it myself. Now I am happy that I didn't read those articles before because now I got it to work. But step by step:
I read on the web that the problem could be that the digital camera is doing two flashes and the external slave flash triggers on the first flash already. Well, I believed, this could be exactly my problem and so I desperated for a while and than I reminded that my flash offers a stroboskope feature (n flashes with frequency f usually used for longer exposure times to have the same - moving - object more than once on the same picture). I thought that what my camera can, my flash is also able to act this way. Then I began to play around with the stroboskope feature and after a long time of making test shots (fortunately I didn't have to bring films to development and wait for it) I found out the proper frequency and optimum exposure time. So my flash also triggered twice. And I saw the flash on the picture.
But I was not really satisfied because the flash was too strong (although in automatic mode). Meanwhile I read even other articles where somebody mentioned that it could be the white balance requiring the 2 flashes. I then tried with the white balance set fixed to flash hoping that now probably one flash is enough. I then played around again with the exposure time but in addition to that I tried to get the correct power of flash (setting the flash to manual mode). After a lot of testing again with direct flash as well as with indirect flash I found out that:
- Exposure time is best with about 1/60 (this is the time that is also used when using only the internal flash) and below. Aperture should be around 5.0.
- Flash should be set to manual - especially when using indirect flash. For direct flash the automatic setting was also ok for a lot of pictures. Therefore power must be manually adjusted to match distance of the subject(s). For indirect flash I use power setting approximately P 2 or 4, for close subjects with direct flash I usually use P 64.
- Flash power should not be set to maximum. I was really surprised by this fact and I discovered this only by accident. It seems that the Metz flash works a little different when doing a full-powered-flash. Working on full power the flash probably is triggered a little too early or too late resulting in dark images.
- Especially when using indirect flash it is important to adjust the Zoom level on the flash which should not be too much in direction wide angle. Better is around 70mm.
- Pay attention on the angle when holding the flash with one hand and shooting with the other. You may easily miss the target with the flash.
- If the sensor of the flash is on a too flat angle against the camera then the sensor might trigger too early or too late. I now after some experience prefer three locations:
- a) Turn around flash to have the sensor looking back to the camera and place the flash slightly before and above the camera.
- b) Turn flash 90 degrees look up in the air for indirect flash and sensor looking back to the camera.
- c) Turn flash 45 degrees having the sensor looking back to the camera in 45 degree angle.
Using direct flash (no matter from which side - and the Hama 6967 adapter works on very flat angles also) I do now have no problems any more - even doing only one flash (without using stroboscope feature) - and even with automatic white-balance.
Only indirect flash sometimes fails giving the disired enlighting. But this may also be given by the fact that I hold the camera in one hand and the flash in the other trying to catch the correct angle.
The tests on the other hand were done with the flash lying on the table and the camera on a tripod.
The camera internal flash I set usually to less than normal power so that it is sufficient to trigger the slave flash but not too strong to disturb the desired effect (visible light coming from the slave flash only).
More information
There are others trying the same. Here are more experiences and tipps: