Wednesday, February 24, 2010

The Little Canon Flash

The small REVUEtron flash has been retired forever. In the last blog I sang his praise which was appropriate as he did indeed good service and it was his retirement speech after all. He is now gone and we can confess openly that he could be a pain in the ass at times.

The manual flash is not very precise as distances have to be estimated. (In advance.) It is completely unpractical in fluid situations when distances change rapidly. In Situations when there is sufficient time to calculate exposure and aperture, like in macro or still photography, the distances from Objects to flash and/or camera are so short that small errors of estimation make a noticeable difference, so one actually needs to measure them.

The (photographic) world was longing for some flash automation.

I planned to make some experiments with the little manual flash and then introduce two automated flash systems. Unfortunately the little REVUEtron left us so that I will jump right to the first flash system, CAT from Canon.

The idea of the CAT system was simple: The lens of the camera is focused anyway to the most important part of the picture, so one can use the focusing information from the lens and translate it somehow into an electronic signal to vary the flash output. (When the DSLRs appeared and the film based TTL did not work anymore. The technique of reading the focusing information from the lens was re-introduced.)

One catch of the Canon CAT system was that it worked only with cameras which where built specifically for it (a trend started by Canon that has become widely the norm today) and it worked only with a few select lenses.

For SLRs the CAT flash was the Speedlite 133D.
For compact cameras without interchangeable lens it was the Canolite D
For the Datematic and the Canon 110 Pocket camera it was the Canolite ED.

The Canolite ED, or short ED, is .... you might have guessed "The Little Canon Flash". I think I never owned a camera which would work with ED. So I really can not remember why and how I bought it. I am however pretty sure that it must have seemed like a good idea at the time. (In the picture ED is connected to a Mecalux 11 optical trigger from Metz.)

It works perfectly in manual mode and has a guide number of 14m. I will use ED for all the experiments I intended for the REVUEtron. ED is still in perfect working condition and I guess that it has to do with the fact that ED is powered by two AA batteries. ED has a flash ready lamp on the back and a guide number table for ISO 100. Any other ISO must be calculated. ED has no manual release switch! The recycle times with fresh batteries are about 3 to 4 seconds. Much faster than the REVUEtron Not bad.

I will not use the flash on a film camera because I am too lazy and to cheap to make the many intended test shots on film. Therefore I needed to trigger ED with a digital camera.

First a word of WARNING. Old flashes can have VERY high voltages on the contacts. Do not ever attach an unknown and/or old flash to your modern digital camera. Always consult your manual about the voltage your camera can take and then measure or look up the flash voltage.

A second word of warning: Your measurement might be very imprecise, but looking it up might not be safer as you put your trust in results that might be manufacturers specs of a new unit. Internet search for trigger voltage might produce a result, but it was measured by someone you don't know. And you do not know how good his equipment and method was.

How does ED measure. My Multitronic measurement device is very slow and therefore not very good in this situation. The problem is, that the flash fires the moment you connect the measuring probes of the Multitronic. So my readings when first charging the flash and then measuring were about 85 V. However I tried a second method by leaving the measurement device attached and then switching the flash on. It will charge and the voltage raises. At some point it will fire.
The reading in this case was about 165V. Hmmm that is the voltage when the flash will EARLIEST fire. I still do not know the voltage when it is FULLY charged, which might be considerable higher.

The Handbook of the Nikon D300s specifies 250V maximum. Sorry ED you will never be attached to it!

At this point I got sidetracked by the question how best to use photocells to fire ED when using Nikon i-TTL.

I have two models of all round photocells available: The Metz lux 11 and the China Import DS-1. The China Import claims to be specifically suited for digital flash systems with pre-flash. The half page manual is in a bit of a garbled English but makes a lot of sense once you ignore the grammar.

I tried three i-ttl flashes on my D300s: SB-800, SB-900 and Metz MZ54 4i

I got some expected and some unexpeced results:

The Metz photocell performed as expected. It did not work at all with any flash. The ED was fired by the pre flash and contributed nothing to the picture.

A flash picture of a flash! So far so good.

But listen to this: I tried the China gadget and it does NOT work with the SB-800 however it does work reliably and repeatedly with either the SB-900 or the MZ54 4i.

Why? I have no clue !


SB-900: Hurray the ED fired in time!

More fun with the ED in the next post.

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