Non-TTL flash for film photography

<p>What is the best kind of non-TTL flash for a film camera, where taking a reading isn't always an option?<br /><br />I have seen flashes that have an aperture and distance gauge, so it's possible to gauge distance/power through that.<br>

This is to use with my Fuji GW67III. I'm not sure if TTL <strong>is</strong> actually an option with film cameras? Please correct me if so, as this would also be an option.</p>

<p>Thryristor controlled flashes like Vivitar 283/285 works well for me.</p>

<p>Some MF film cameras have TTL capability: Hasselblad 503 for instance.</p>

<p>I can answer your last question - yes, but it depends on the camera. I believe that a film camera would need, inter alia, an electronic shutter for ttl flash.</p>

<p>Thanks, I've just realised that I am able to calculate this with my Yungnuo 560 (GN of 58) using the table.<br>

I am having difficulty getting mead around it, ie. calculating flash power required at a certain aperture and distance, for example f8 at 2 metres (ISO 400). </p>

<p>Does anyone know of any <strong>practical</strong> guide to using this method? I have found lots of long winded guides and calculators, but would like to see how it is done in practice.</p>

<p>I have a bunch of Vivitar 283 and 285 flashes that work fine for me. You set the ISO on the flash and it gives you a choice of four f-stops to use with a color code next to each. You set the sensor of the front of the flash to match and the flash does the rest. Of course you can also use them on manual. Nothing fancy but cheap and reliable. If you want something newer, go to <a href="http://www.strobist.com">www.strobist.com</a> and see his recommendations.</p>

<p>Many flashes have non TTL auto mode and that's would be just as quick to use as TTL. In theory it's not as accurate as TTL because the light sensor is on the flash and not in the camera and looking thru the lens but in practice I see little difference.</p>

<p>To set your flash with GN 58 for f8 @2m ISO 400, note this is f29 @2m ISO 100 , say f32.<br>

Here is a sequence of flash numbers:<br>

http://pleasemakeanote.blogspot.co.uk/2010/10/mathematics-of-fstop-aperture-numbers.html<br>

For ISO 400 f32 converts to f64.<br>

The sequence of flash power is then Full=f64, 1/2=f45, 1/4=f32, 1/8=f22, 1/16=f16 1/32=f11, 1/64=f8. So to get f8 @2m ISO 400 set flash at 1/64 power or a bit higher (because of the approximation f29 =say f32)<br>

I think that's right but no guarantee.I have a Yongnuo 560 as well.</p>

<p>I see that many new flashes do not have a non TTL auto mode so if your camera doesn't support TTL you have to use manual mode with GN which is quite slow to use. </p>

<p>Craig, you brought back memories. In those days, when as McNally said, I would take the little hammer and break the glass that said break only in case of emergency over a compartment where the Vivitar flash was kept. I have one of the 283's and a 285. Now I would just suggest a meter whenever possible. </p>

<p>Hi</p>

<p>There is a very simple relationship between guid number (GN), object distance (D) and f-number (N):<br>

GN = D x N at ISO 100<br>

Remember that D is in meters if GN is in meters, D is in feet if GN is in feet.<br>

Have a look at this article in Wikipedia:<br>

http://en.wikipedia.org/wiki/Guide_number</p>

<p>Regarding zoom flashes and guide numbers, have a look at this discussion over in dpreview (GN varies with zoom):<br>

http://www.dpreview.com/forums/thread/3386098#forum-post-55965701</p>

<p>Cheers,</p>

<p>Like Craig I used Vivitar 283 units with my Nikon FM2n cameras together for years. I shot with Tri-X and HP-5 often and recall the Vivitar's yellow setting was f/5.6. Worked very nicely.</p>

<p>Henry Posner<br /><strong>B&H Photo-Video</strong></p>

<blockquote>

<p>There is a very simple relationship between guid number (GN), object distance (D) and f-number (N):<br />GN = D x N at ISO 100</p>

</blockquote>

<p>It's quite simple but try to do the calculation while shooting an event and especially when you need to bounce the flash. I found if I have to I can just set by experience and then chimp and it's still faster. </p>

<p>Henry's got it exactly right. Tri-X in my F2 and FM bodies with the 283 on yellow and the lens on 5.6 nailed thousands of shots. The yellow setting was good out to about 40 feet and 5.6 was small enough to give some depth of field (focus was manual back then). Maybe it was the wide latitude of the negative film, but I had no need at all for anything more sophisticated.</p>

<blockquote>

<p>I found if I have to I can just set by experience and then chimp and it's still faster.</p>

</blockquote>

<p>Agree. When I use manual flash, it is for macro where things tend to be more straightfarward.<br>

My post was ment for explaining what the guide number is (and maybe what it isn't).</p>

<p>You need to bear in mind that the people who write Guide Number tables seem all to be pathological liars! Every single published GN table is out by about a stop - on the optimistic side to make the flash look more powerful than it really is. Most top-of-the-range speedlights (or lites) have a true GN of around 28 (in metres) @ 100 ISO and with the 50mm head setting. The GN doesn't actually increase very much in going from 50mm to 105mm or whatever. You might gain a stop at best; giving a GN of around 40 at the maximum zoom setting. There ain't a hotshoe flash on the market that acheives a true and measured GN of 58.</p>

<p>Anyhow. Working back from a GN to a power setting is a bit tricky, because GNs are linked to the aperture number series, which is based on the square root of two =~1.4. So doubling the power of the flash (or doubling the ISO speed) only increases the GN by a factor of 1.4. Likewise if you halve the flash power or the ISO speed, the GN is divided by 1.4.</p>

<p>Going from 100 ISO to 400 ISO is easy - you just double the GN. And going from full to 1/4 power on the flash is easy too, you just halve the GN. However, single stop steps require multiplying or dividing the GN by 1.4.<br /> Half stops? - Don't even go there!</p>

<blockquote>

<p>"..but would like to see how it is done in practise."</p>

</blockquote>

<p>Let's assume your flash is typical and has a GN of 28m @100 ISO and you want to use 400 ISO film instead. So we double the GN to 56. Then you want a distance of 2 metres and an F-number of 8. Distance x F-number = 2x8 =16. Divide the full-power GN of 56 by 16 and we get 3.5. Divide 1.4 (our magic sqrt2 number) by 3.5 and we get 0.4. So the flash power has to be turned down to 0.4 of its full power. On flashes that allow power decrements in 1/3rd stops, that would be 1/2 power -0.3 stops, or near enough. 1/2 power would probably be within normal exposure tolerances though.<br /> </p>

 

<p>Whoops. That calculation above should read "Take the square of 3.5 and invert it = approximately 1/12. That's the power factor you need - 1/12th power, or about 1/8th power - 0.7 stops.</p>

<p>Sorry, I was trying to make the maths simpler and got into a mental tangle. There's actually no easy way to do GN calculations back to power factors. A calculator is almost essential.</p>

<p>Correct Joe! I can do all the calculations for the fun of it but when I am shooting it's way too easy to make a mistake.</p>

I used two Vivitar 285 HVs for years with film cameras. Wedding shooters used the yellow mode for fill and eye highlights they preached.... Auto exposure using the color modes like yellow typically gave reliable results. Also Vivitar produced a number of useful accessories for their flashes. The cartridge holder allowed simple changing of the four AA cells. The HV models were also capable of using third party power packs for quick recycle.. Auto mode still works well, and has not been overtaken by TTL as much as the vendors like to believe. I would disagree with the pathological lying part that Joe asserts, though they tend to produce the best face on things. I am not sure that guide numbers were interpreted as a reliable standard at any rate.. You have to do your own tests to zero in. But as to ease of use, the Vivitars ( thinking of the auto thyristor models) were so good that there were books written on how to get the most of the popular Vivitars. LIke this fine comprehensive one by Susan McCartney:

 

http://www.amazon.com/Mastering-Flash-Photography-Advanced-Techniques/dp/0817445455/ref=sr_1_5?s=books&ie=UTF8&qid=1440538322&sr=1-5&keywords=Mastering+flash+photography