Help with T90/300TL : LUSENET : Canon FD : One Thread

Anyone know a good source (preferably on the Internet)where I can get a CLEAR explanation and instructions for using the 300TL and T90. Both manuals (T90 and 300TL) read clear as mud.


-- A.G. Lang (, April 16, 2002


You could try a book called 'Canon T90' by Richard Hunecke which is clear in the way it goes into detail. I mention this particular book because it is in a current eBay auction

The original brochure is also quite informative of all the features your camera has and what they are for although I don't know where you would get one.

The T90 is not that difficult to use really. I just practised on mine until I knew what everything did. I don't have a 300TL though, I use a 299T which works fine.

-- Joe Margetts (, April 16, 2002.

In reference to the Hunecke T90 book, it is very informative and available from new for $17.90 plus postage. They also have the Hove book that covers the Canon Speedlites (550ex,540ez,430ez,420ez,includes 300tl) which gives some good info on these flashes and flash photography in general.

-- Terry Taylor (, April 16, 2002.

Careful what you ask for. . .

I agree with both you and Joe: The original manuals are less than perfect but, then, the T90 rapidly becomes intuitive (except, perhaps for its strange approximation of fully manual metering, but that's another story.)

The 300TL seems to multiply, drastically, the options and responsibilities available to the operator. Because I only use my flash occasionally, I often stand there stupidly wondering if I've done things right while my subjects grow impatient. There are several authoritative sources to help you puzzle out this magnificent strobe, though. Describing them each is going to take a while, so bear with me.

Hunecke's book is pretty good and I recommend it, too, but I swear it's translated from German because the sentance structure sometimes leaves me scratching my head. Some crucial bits make more sense on the camera than they do in his text. Apparently, his book was originally published with colour photos (they're B&W in my copy), so you might want to find an earlier edition. My buddy Gerry Siegel notes the following in his 1999 post at g/T90MBoard/index23.htm : 192pp., by Richard Hunecke, Hove Fountain Books, ISBN 0-86343-074-0, reprinted 1989, by Hove Foto, US distributor Saunders Group, UK Distributor was Newpro UK Ltd.

Gerry also suggests the "'Canon User's Guide [to] Speedlites 420/430/540EZ,' features Speedlite 300TL and numerous references to T- 90, Hove Foto Books by Philip Raby, ISBN 1-874031-54-1, Note: currently [the] only reference in this list that is readily in stock and reliably available by mail!"

The most detailed resource for the 300TL is from Canon and it's actually TWO SEPARATE PUBLICATIONS, each called "the Speedlite Reference Guide." In my research, it took me three years to suspect everyone was discussing two books, not one, and another couple of years to confirm I was right.

Both books are out of print and Canon will not grant permission to post either on the web. (I've spoken directly to the author about this; no dice -- but that doesn't mean they're not out there.) The first is entitled "Canon's Reference Guide for the 300TL Speedlite" by the Canon U.S.A. Technical Department (Chuck Westfall & Richard Bellomy), 1987, 30pp. Its cover has a small drawing of a waitress carrying a T90 on a tray. It discusses in detail how the camera and flash operate and all the various configurations for interconnecting wires.

The first book was available at and may still be there.

The second is entitled "Speedlite Reference Guide" by Canon, 1991, 76pp. The author was, again, Chuck Westfall. The cover shows three Speedlites against a background of vertical stripes. This book is significantly broader than the first but no less deep. It covers Speeedlites 430EZ, 420EZ, 300TL, 300EZ, 200E, 160E, ML-2, ML-3 and the cameras EOS-1, T90, EOS 10s, EOS 630/EOS RT, EOS 650/EOS 620, EOS 700, EOS 750/EOS 850, and the EOS Rebel, as well as the assorted flash accessories.

Because the second book tells you what to expect when you use other flashes on your T90, it's the much more valuable reference. (No other Canon Speedlite, old or new, will provide all the features provided by the 300TL.)

I once condensed down all my 300TL sources into a reply to a Photo.Net forum question about bad flash results. Now, I keep a copy with me as a cheat sheet for when I get bewildered. I'll dump it again for you. (Just a note, first. If you put the 300TL on the "Off-Camera Cord 2" it will know it's NOT in the hot shoe and pointed straight forward, so it will always act as though you had twisted the head to "bounce" the light. Further, if you put the 300TL on any combination of Canon's modular cables/cords, distributors, Off-Camera Shoes, and what-have-you, the flash will assume it's not the only flash and so it will NOT use its light sensor in the usual manner.)




Original ("simple") TTL works with a light sensor picking up light reflected from the entire frame of the film. The aperture and shutter speed are controlled by the camera and the light sensor just turns off the flash when it thinks the whole picture is exposed enough. The sensor only does it's job adjusting the flash during the exposure. If there's a lot of ambient light, which the sensor can't control, the picture will be overexposed.

The 300TL can use A-TTL (Advanced-TTL) or FEL (Flash Exposure Lock). Canon tells us A-TTL is easier while FEL gives more control.

In both A-TTL and FEL, the 300TL measures ambient light before the shutter opens and uses this measurement to decide how much flash to apply. If it's dark out, you'll get three times as much flash as if you're in daylight. This means you get a weaker fill-flash at daytime and a strong spotlight at night.

A-TTL and FEL act differently after this: A-TTL blinks out a pre- flash -- either infrared, if the 300TL is pointing straight ahead, or a weak (5%) white flash if its pointed toward the wall or the ceiling. The light sensor ON THE FLASH measures whatever bounces back so the flash knows how reflective your target is. The 300TL's light sensor measures an area of 14 degrees which equals the area of a 180mm lens or 30% of the area of a 50mm lens. TO ADJUST THE A-TTL POWER: Adjust the Exposure Compensation Index (the highlight / shadow buttons on the T90 next to your thumb) OR change the ISO setting to 'lie' to the T90 about what speed film you're using. Be careful, because doing either of these will also change the ambient light exposure.

FEL is different: To use FEL, press the spot meter button on the T90. This gets the ambient light reading I mentioned above. It also causes a 5% white flash to leap from the 300TL which is measured BY THE SPOT METER IN THE CAMERA (not reflected off the film) and stored for 30 seconds while you recompose the picture and shoot. This way, you can adjust the flash for only the bit of your target in the viewfinder's 'spot zone.' If 30 seconds is not enough time, you can retain the flash reading for more time by pressing the Exposure Preview button on the back of the camera.

Perhaps you are missing (as I sometimes do) the 'bad exposure' warnings you're getting. I'll cover the warnings the camera gives you and how to fix them for each mode:

FULL PROGRAM MODE / PROGRAM A-TTL: The "full program" modes do everything for you. You either 1) put the 300TL in "P" and lens to "A" or 2) put the 300TL in "Mode Set + A-TTL" and the camera in Program, or P. To quote the 1987 _Reference_Guide_, "There is no difference between Full Auto Mode and any kind of Program A-TTL." VIEWFINDER WARNING: Both speed and aperture blink (after the pre- flash) when you're out of range. SOLUTION: Move closer and pre- flash again until the blinking stops.

SHUTTER PRIORITY (Tv) AND APERTURE PRIORITY (Av) A-TTL: These modes give fill-flash, only. In Tv, set the speed from 30" to 1/250. In Av set the aperture. The viewfinder readings will be completely different from the program modes because now only the ambient light is being measured. The fill will be added later. VIEWFINDER WARNING 1: Speed OR aperture will blink if the ambient light is too little or too much for your camera settings. SOLUTION 1: Give up and either use Program A-TTL or put the camera in manual and pick your own settings. VIEWFINDER WARNING 2: Both displays will blink if the target is too far for your aperture. SOLUTION 2: Move closer or open the aperture. Or get a faster lens.

STOP-DOWN AE A-TTL (for lenses where you have to manually set the aperture): Adjust the aperture ring, set the camera to Program, P, or Av. The shutter will be set by the camera based only on ambient light. VIEWFINDER WARNING: Blinks if shutter speed must be outside the 30" - 1/250 range or if you're too far away. SOLUTION: Move closer or open the aperture. Or get a faster lens.

(After this, the viewfinder 'warnings' get more subtle. . .)

PROGRAM FEL: You set the 300TL to "Mode Set + FEL" and the T90 to Program or P. You aim at the "spot" you want to meter and press the spot button. The camera sets the aperture (based on the pre-flash) and speed (between 1/60 and 1/250.) Recompose and shoot. VIEWFINDER WARNING: The dot on the right edge of the spot metering scale must be at the same height as the triangle index marker. SOLUTION: If the dot is too high (nearly impossible) move further away from your subject. If the dot is too low, move closer.

Av FEL: An amazingly useful mode! Pick a good metering pattern to measure the available light. Put the spot meter zone over your main subject and press the spot button. VIEWFINDER WARNING / SOLUTION 1: If the dot is higher than the triangle move further away or close the aperture. If too high, get closer or open up a bit. Now you've got the correct flash exposure for your subject. Next, watch as the floating bar moves up and down between the dot and the triangle. If the bar is lined up with the triangle, too, the background will be correctly exposed. Your aperture controls the flash exposure and your shutter speed controls the ambient light exposure. To change the background (ambient) exposure, move the floating bar by adjusting the shutter speed with the Highlight and Shadow buttons. You can set the speed (displayed in the viewfinder) anywhere from 30" to 1/250. Also, you can fine-tune the flash exposure by changing the aperture with the input dial. This lets you tweak just the light on your subject.

Tv FEL: The 1987 _Guide_ tells us this mode is not very useful, unless you are switching between flash and ambient light for moving subjects. The same rules apply for the dot and the triangle but you have less control. The Highlight & Shadow buttons change both the ambient and the flash exposure, so don't bother with them. The input dial changes the background exposure by shifting the shutter speed. (The aperture balances automatically to keep the subject correctly exposed.) Doing another pre-flash will match the flash output to the new speed.

STOP-DOWN AE FEL: Set the camera to Program, P, or Av. Set the lens aperture manually and lock the stop-down lever on the camera. Pressing the spot button will lock in the correct flash for the spot zone in the viewfinder and set the correct shutter speed for the ambient light. Use the Highlight / Shadow buttons to adjust background lighting. Adjust flash exposure with aperture ring on the lens.

STOP-DOWN FIXED-INDEX FEL: This mode is where you pretend you're using a match-needle meter, as in an FTb or other, earlier Canon camera. Set the T90 to Tv but set the aperture manually with the lens ring. Lock in the stop-down lever. Take meter readings with a half-press of the shutter and you'll see the vertical viewfinder scale light up. At the bottom, the red LEDs will tell you to either open or close the aperture by displaying "OP" or "CL." This mode also lets you use that neat viewfinder scale to take readings in average or partial metering. That's normal SDFI. Now, we'll add the flash: Set the 300TL to FEL and press the spot button to get your pre-flash. The Highlight / Shadow buttons don't work now, so use the shutter speed to adjust ambient exposure. Now, the viewfinder LEDs say "HS" (Higher Speed) or "LS" (Lower Speed) if the backgound exposure needs fixing. The same old rules apply for the dot and triangle so you can see what you're doing when you adjust the subject (flash) lighting with the aperture ring. Make sure to correct the background exposure with the shutter speed when you do.

MANUAL CAMERA / SIMPLE TTL AUTOMATIC FLASH: (The last one!) This gets you control over BOTH speed and aperture AND automatic TTL falsh exposure. Set the flash to either A-TTL or FEL, the T90 to Tv, and pick a speed between 30" and 1/120. Take the lens ring off of "A" and set your aperture with it. First, measure the available light: either use a hand-held meter or just use the T90 by turning the flash OFF so it won't deactivate the camera's meter -- and remember to stay below 1/250. Change the shutter speed to lighten or darken the background. Raise the film ISO to underexpose the flash; lower the ISO to overexpose it. Be sure you stay within the numbers on the automatic distance range chart (the sticker that came with the 300TL). Be careful that lots of ambient light doesn't wash out your image. This isn't a great mode for daytime.

Three other "TTL Auto" Variations:

1) Same as above but camera in Program, P, or Av. Gives you TTL Auto at 1/250 speed, only.

2) Camera in Program, P, Av, Tv, or Stop-Down AE. Lens on "A" but under stop-down control. Flash in "Mode Set" but with none of the four mode buttons pushed in. The ambient light exposure will be set as if there was no flash but the flash exposure will be TTL Auto at the aperture in the viewfinder or on the lens. (In Program or P on the T90, your speeds can only go from 1/60 to 1/250.)

3) Camera in Program, P, Av, Tv, Stop-Down AE, or Stop-Down Fixed- Index. Lens on "A" but under stop-down control. Flash on FEL. Now, if you 'forget' to hit the spot button before you shoot, you'll get TTL Auto at the aperture in the viewfinder or on the lens.

-- Robert Segal (, April 16, 2002.

Thank you all so much. I must have been dozing when I posted the question. I listed my old (closed) email address.

-- adam g. lang (, April 16, 2002.

Thanks again, I printed the rference guide off the site specified, very helpful.

My memory was jogged by the post and found that I also have a copy of the Speedlite reference guide sent to me by Chuck Westfall (great guy, a great asset for Canon USA, if he still works there) when I asked a similar question a few years back on the old CompuServe Photography forum. Never got around to reading it, guess I'm not real big on flash. But THIS time I shall master it!

-- adam g. lang (, April 17, 2002.

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