Using T32 Flash With E-P2

<p>Owning most of the T series of flash guns for use with the OM series of cameras, I have been finding out how they work with my E-P2. Intitially this was done for macro.<br>

The short version of the story: The sensor is far more sensitive than film is to flash, hence some surprising settings.<br>

The outcome: ISO 100 or 200 can be used for most purposes.<br>

The camera/lens settings: M (manual) or S (shutter), shutter 160, ISO 100, f8.<br>

Flash gun (T32) settings: Manual (slider reversed), ISO 25, f4.<br>

This gives good exposure at about 6ft (just under 2m). (Other distances not tried).<br>

For bounced flash (45 degrees off white domestic ceiling), use ISO 200.<br>

All of the above done in a mostly white kitchen.<br>

T32 flash guns are readily available at little cost compared with dedicated units.<br>

For larger apertures either select a higher one on the flash gun and/or use some diffusion or reduction of the flash is required. There is a filter kit for the T32 which contains ND filters and a wide angle (21mm lens) diffuser. For smaller apertures select a higher ISO.<br>

I hope this starting point helps someone.</p>

<p> </p>

<p>Interesting observations, thanks for sharing.</p>

<p>I've successfully used digital cameras with a number of these older style flashguns - the ones with sensors on the front which measure the light coming back from the scene and cut off the flash when the required exposure's reached. They work rather well provided you keep an eye on the trigger voltage and don't fry the camera! But I can't see why you are making the exposure settings so complicated. I just tried my T32 on my Canon Powershot G5 (don't have an EP-2). I just set the flash and camera to 200 ISO, selected F5.6 on the "Normal Auto" slider of the gun, and put the camera on manual, f5.6 and 1/250th, and the T32 seems to expose the shots pretty well, both for direct and bounce flash, and at various distances. That's what the auto mode is designed to do, whether with a film camera or digital, why not let it do its job?<br>

<br />I'm not sure why you seem to think that a digital sensor is "far more sensitive than film is to flash". Could it be something to do with the mostly white kitchen you are working in?</p>

<p>I know of one sitting in a thrift store in Pacific Grove right now, about $10 I think. It would look big on an M4/3 camera. Can I assume any Olympus flash, old or new would not cause problems on a Panasonic Lumix camera? </p>

<p>Better check the flash trigger voltage before using older flash on newer cameras. Some may be high enough to damage the camera. One of my older Olympus flash units has a high trigger voltage and is unsafe for anything other than simple manual cameras.</p>

<p>There are safe sync devices and optical triggers to use older high voltage flash units safely with newer cameras. I have a couple of these and they work fine.</p>

<blockquote>

<p>"The sensor is far more sensitive than film is to flash, hence some surprising settings."</p>

</blockquote>

<p>If you double check with an accurate incident and flash meter you'll probably find the difference is explained by other factors. Digital sensors are not more sensitive, but occasionally nominal ISO ratings are significantly off spec - a 1/3 EV difference is enough to be visible.</p>

<p>Shutter speeds and apertures can also vary somewhat from nominal specs, enough to produce visible differences. So can in camera JPEG processing.</p>

<p>This is a project in which the E-P2 had no control over the flash power. This was done by another camera, an OM4. It clearly demonstrates the difference on sensitivity:<br>

<a href="http://www.photomacrography.net/forum/viewtopic.php?t=16626&postdays=0&postorder=asc&highlight=proxy&start=0">http://www.photomacrography.net/forum/viewtopic.php?t=16626&postdays=0&postorder=asc&highlight=proxy&start=0</a><br>

(Alan Wood has looked at this and has yet to tell me I'm wrong).<br>

Maybe someone would like to try the other way round, using digital flash on a film camera?</p>

<p>I think I have worked out what is going on.<br>

For this purpose, ignore the actual exposure settings for my proxy metering project, as macro magnification factors were involved. Using the two cameras cancelled that out. So we need only consider the relative exposures on the digital versus film camera.<br>

To summarise the macro findings, where the E-P2 (manual, 160 sec) had no part in triggering or metering the flash. The E-P2 set at f11 (required aperture, manual lens) and ISO 100 was equivalent to f2.5 at ISO 400 on the film camera.<br>

The key factor is that the E-P2 didn't 'know' it was flash illumination and treated it as ambient light with no metering. In these circumstances, the sensor <em>is</em> several stops more sensitive to the flash light than is the film camera.<br>

It seems that when the E-P2 triggers the flash it changes the sensitivity of the sensor to match flash illumination to the sensor ISO. Film would not do this. So it seems that the sensor is more sensitive to flash than is film but that is dealt with internallly in flash mode. This indicates that alternaltive electronics are needed for fill flash.</p>

<p> </p>

<p>Correction "E-P2 (manual, 160 sec)" should be E-P2 (manual, 1 sec). This was effectively a "bulb" setting but was the shortest exposure in which I could be sure to fire the E-P2 while the shutter was open. (The room had very subdued light to prevent ambient light contributing measurably).<br>

(I am now using manual,1/160 for outdoor macro flash with similar T32 settings).</p>

<p>Correction "E-P2 (manual, 160 sec)" should be E-P2 (manual, 1 sec). This was effectively a "bulb" setting but was the shortest exposure in which I could be sure to fire the E-P2 while the shutter was open. (The room had very subdued light to prevent ambient light contributing measurably).<br>

(I am now using manual,1/160 for outdoor macro flash with similar T32 settings).</p>

<p>In macro photography I'd suspect the bellows effect unless you're using an aperture corrected macro lens.</p>

<p>If you're using the same lens on a 35mm film SLR and a Micro 4/3 digital camera to get the same magnification, you'll need to adjust for the differences between camera-to-subject distance and the bellows effect in the extended macro lens tube. That would probably account for the exposure differences you're seeing, rather than any significant differences in sensor/film sensitivity at any given ISO.</p>

<p>No, it wouldn't even come close.</p>

<p>If you're looking for a solution to what appears to be the original premise...</p>

<blockquote>

<p>"The sensor is far more sensitive than film is to flash"</p>

</blockquote>

<p>...I'd suggest reexamining your methodology.</p>

<p>The least likely answer is "the sensor actually is far more sensitive than film to flash." The most likely answer is to be found somewhere else in the process.</p>

<p>If I encountered results like you've described, I'd start by using my flash meter to determine whether the flash output was consistent at every setting, distance, etc. An older flash unit like the T32 is likely to have developed some inconsistencies due to aging. In my own older flash units I've needed to exercise or reform the capacitors to produce consistent results. In most cases - as long as the flash units weren't defective or needed new caps - reforming the caps usually involved several cycles of fully charging the flash, popping it at full output and repeating the cycle a dozen or so times. If I haven't used the flash for awhile I'll repeat the process, using my flash meter to determine when the output is consistent.</p>

<p>On the other hand, if you're satisfied with your methodology for your purposes, that's good enough. Whatever works, works. I'd only by skeptical regarding the premise that a digital sensor is more sensitive to flash at a given ISO than film of the same ISO.</p>

<p>I kept the story simple I did not mention here that I used two diifferent T32s and two OM4s (4 combinations). I did find a small, initial difference in the ambient light metering of the two OM4s, due to a battery life nearing its end.<br>

Anyone out there can simply replicate what I did, ignoring the macro element. The effect is real but only for off-camera flash.<br>

"Whatever works, works." Precisely. More important: whatever does not work does not work. This caused great hesitation at the beginning of my project. Had the film and digital relative sensitivity been reversed, I might have shot several rolls of film, using a digital flash, and maybe susbsequently had my OM4s needlessly serviced and perhaps had an almighty row with the processing lab.<br>

As for recycling, I would probably qualify for the Olympics! :)<br>

The original intention was to calibrate my fully manual Vivitar (meter not used) and Sunpack (no meter) flash guns for use with digital. I used those for many years with 25 ISO film on a twin macro flash unit in my pre OM days. This gives correct exposure every time. That was going to involve a hand-held flash meter. The sensitivity issue diverted my efforts. The proxy method gives the same results but lacks flexibility, although it gives bonus, such as perfect back-lit exposures.<br>

<a href="http://www.photomacrography.net/forum/viewtopic.php?p=107626#107626">http://www.photomacrography.net/forum/viewtopic.php?p=107626#107626</a><br>

I can now proceed with that, after it, for many weeks, seemed doomed. That fully manual flash will not require exposure adjustment for the lightness or darkness of the backgrounds, as the current use of the T32 on the E-P2 does. (Yes, there is considerable scope for post-processing to adjust that but why not get it right in the first place?).</p>

 

<p>Lex Jenkins advice on checking the trigger voltage is worth to consider. According to the list at<br>

http://www.botzilla.com/photo/strobeVolts.html<br>

the Olympus T flashes should be fine, but I measured on the earlier Quick Auto 300, 310 trigger voltages in the 250V range, and the even older PS200/PS200Quick ca. 190V.</p>

<p>Thanks, Konrad.<br>

I hadn't seen that website before.<br>

I have two Vivitar 283s. One was one of the last made. The other is decades older. Umm, now which is which?<br>

I will use them via a slave trigger, with a small T flash on the E-P2 hotshoe.</p>