Is it safe to use old flashes on modern cameras?

Sometimes the possible consequences of connecting old flashes to modern electronic cameras (both digital and film) through hot shoe are discussed. The problem is high voltage (up to at least 300 V) of those flash units on their contacts, exceeding the standard limit of 12 V. I’ve never heard about a destroyed camera from direct user experience, but people are warned not to try such things.

What’s my own experience? An old simple hot shoe flash with voltage about 90 V on its contacts usually worked with my Pentax MZ-M camera, but I sometimes experienced delayed mirror return (for about half a second) after taking a snapshot. I was more cautious with my other body, Pentax Z-1, reported to be sensitive to high voltages. I once attached another flash unit, 40 V, to it. Two snapshots went fine, but on the third one it actually happened what the rumors had warned about: the camera got completely frozen and I had to remove the battery from it to get it alive again. However no other damage has happened.

I no longer risk damaging my cameras by using old flash units. I bought a used Pentax flash unit for €15, with safe voltage. It is only a bit stronger than common built-in flashes, it doesn’t have any TTL etc., but it works, it’s safe, cheap, small, light, inconspicuous and communicates with the Pentax cameras. It’s enough for my occasional flash use.

This is my warning to other photo amateurs: Although no permanent damage has happened to my cameras, I can confirm that using old flashes with voltage higher than 12 V on their contacts may cause at least temporary malfunctions. And it’s not true that Pentax cameras are safe up to 600 V.

Printer calibration

Some time ago I’ve finally managed to get my Epson R220 printer somewhat calibrated. Standard Gutenprint drivers suffer from strong green cast on this printer and I wasn’t successful to get it corrected directly in Gutenprint. Trying to play with the driver color settings has led me only to other problems, replacing one kind of color cast with a different one. Much better than standard settings but still not always usable. So the only way to print photos on my printer was performing printer color calibration. How did I do it?

First I installed Argyll color management system. It’s not included in Debian (I guess not many people perform color calibration regularly and they are scared of irregularly maintained software with lots of possible problems) but it can be compiled and run easily. It’s just not easy to use it. But it contains complete documentation, so with enough time, patience, ink, and paper it’s possible to get the desired results. I didn’t have enough time during last year so it took me more than one year, but it seems to work now.

The first step was to calibrate my desktop scanner. This was necessary to scan the printed samples for calibration processing. I ordered a scanner color calibration target from Wolf Faust and followed instructions from Argyll documentation. This step was relatively easy and I got my scanner calibrated soon.

The next step was significantly harder. When I tried to generate color patches for my 6-color ink printer Argyll created just greyscale patches. I didn’t understand it, although the Gutenprint driver apparently uses inks other than black even on greyscale images (as long as color printing is enabled), I decided not to go this way. So I generated and used patches for an RGB printer. Yes, it’s probably completely wrong from the point of serious calibration, but it basically works. First I tried to generate the patches for the target 10×15 media but the number of the patches on this area was too small and the calibration results were bad. I didn’t have a larger piece of paper of this kind so I used a different kind of paper in A4 size. Professionals would probably fall faint reading this but I wasn’t willing to spend another €15 for paper in order to print our family photos perfectly. Then I had to scan the printed results and to process them with Argyll. The process was smooth once I had managed to use proper commands with proper arguments and proper use of the srgb.icm file (taken from digiKam).

The final step was setting the color profile in PhotoPrint. This was easy and worked very well.

Of course my calibration process had several serious flaws: I used a desktop scanner instead of a proper measurement tool, I generated color patches for another kind of printer and I used different kinds of paper for calibration and printing. But the results are still better than any of my previous attempts of manual adjustments. They are not perfect, but my old digital camera is not either, not mentioning my uncalibrated monitor. And I’m glad that faces on the printed photos are no longer green nor violet. This makes my family satisfied enough :-), so this poor man color calibration fulfilled its purpose.