Anyone else use this camera with flash?

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GreenLarry
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Anyone else use this camera with flash?

Post by GreenLarry »

I have a Canon EOS 300 (EOS Rebel 2000 to you guys), and I recently bought a TTL off~the~shoe adaptor, which works fine with my Cobra 440AF flashgun.

However, I seem to remember last time I used it I had trouble setting an aperture that I wanted when in a auto mode, and when I put it in manual it tells me that at f22 I am often drastically underesxposing with a shutter speed of 1/90(flash synch speed)

Can I just put it in manual, set the shutter spped to 1/90 and use any aperture I want and let the E-TTL flash sort things out?

I'll be using print film so theres considerable latitude, which does mask out a lot of errors making it difficult at times to see if you got it wrong!

Thanks all
~Larry~

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GreenLarry
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Post by GreenLarry »

I really could do with some help with this (scrathing head) :?

rjlittlefield
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Post by rjlittlefield »

Larry,

OK, maybe a little information is better than none at all.

In theory, E-TTL should be able to sort it out.

But I don't completely trust the theory.

The reason is, I own a Canon Digital Rebel, and I bought and returned several different E-TTL flashes because they wouldn't work right with hardcore manual-aperture setups like reversed lenses on bellows.

After much thrashing around, I finally realized that for me, straight manual operation works just fine, given the rapid feedback of digital to help me set things up.

Unfortunately, straight manual is a serious pain in the rear with film, so I can't recommend it to you.

I do know that my Digital Rebel's internal E-TTL flash works fine with Canon's automatic lenses, if I manually set 1/200 (minimum flash sync speed) and any sufficiently wide f/stop depending on ISO setting and distance to subject. What seems to mess up the works is when I swap in fully manual optics.

Best I can recommend is to read all your manuals again, then try what you suggest (let E-TTL sort things out), and see if it works.

You can tell from the negatives if you're getting proper exposures. If you've got detail everywhere you care about, and the darkest shadows/blacks are not quite clear film, it's perfect.

--Rik

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GreenLarry
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Post by GreenLarry »

Thanks Rik, I'll have to dabble and see.

Im sure i have some other shots somewhere of flowers taken with this set up, but i have photos EVERYWHERE!

Going digital would certainly be a benefit in that department!

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Post by twebster »

Here's everything you ever wanted to know about Canon flashes, Flash Photography with Canon EOS Cameras.
Tom Webster
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GreenLarry
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Post by GreenLarry »

Thanks Tom, I saved the page!

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wilash
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Post by wilash »

You may find the answer a simple one. TTL flash cannot be used with such small apertures. There is not enough light for the metering system to respond so flashes and cameras are not designed to work at f/22. The only way is to use manual control of flash and camera exposures.
Will

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Post by rjlittlefield »

Hhmm...

E-TTL at f/45 works fine for me, even with my Canon Digital Rebel's wimpy little pop-up flash.

Of course that's only for macro work, out to a couple of feet and down to 1:1 with my Sigma 105mm. :) 8)

I'll bet the E-TTL works fine as long as the flash has at least enough power to make a good exposure at whatever distance, magnification, f/stop, and film speed you're using.

Unless, that is, you run into some silly firmware bug like my Digital Rebel's not working with really manual apertures. I think I would have been completely happy with my E-TTL strobes except for my penchant to using reversed enlarging lenses and microscope objectives on bellows, and still expecting auto-exposure to work (which it should, grouse gripe :!: :evil: )

--Rik

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Post by MikeBinOKlahoma »

ETTL and TTL are different (in the Canon system), and that may be part of the original problem (if the adapter is intended for TTL).

TTL works by measuring the light of the flash reflected from film. I haven't ever used TTL, but I assume that's the reason for the f/stop limitation Wilash mentioned.

ETTL works by the flash prefiring a low-power burst, and measuring the reflected light. This doesn't depend on aperture for the measurement to work.

Larry, you might want to verify that you aren't mixing equipment intended for TTL only in with equipment in ETTL and getting weird results because of that.

I only have experience with ETTL and digital (digital sensors have different reflectivity than film, so TTL won't work at all with them) so I can't be more helpful than that, I'm afraid.

If you're actually using TTL for all purposes, and threw in "ETTL" once as an oversight, what I just wrote isn't going to help.
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rjlittlefield
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Post by rjlittlefield »

I used to use TTL flash a bunch, albeit with Pentax rather than Canon equipment. It was quite robust, especially with strange optics, precisely because it measured exactly what hit the film under image-forming conditions. E-TTL basically assumes that it can predict what is going to hit the sensor, after the camera stops down the lens and the flash does its best to put out however much light the camera ordered. E-TTL is a predictive system, where TTL was strictly reactive. For accuracy and robustness, I'll put my money on reactive any day. With a nice bright flash at a short distance, my Pentax TTL was lark happy exposing through a pinhole at the end of a bellows.

Unfortunately, as I understand the issue, TTL flash essentially requires a sensor that is itself a diffuse reflector, and digital sensors were too shiny to make it work. So reactive is out and predictive is in.

It would not be a bad tradeoff, except for that silly firmware bug that I'm hoping appears only in the exact model Digital Rebel that I have.

--Rik

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Re: Anyone else use this camera with flash?

Post by rjlittlefield »

GreenLarry wrote:when I put it in manual it tells me that at f22 I am often drastically underesxposing with a shutter speed of 1/90
By the way, my Digital Rebel does the same thing, even though the E-TTL flash makes a fine image. The problem is only that the camera has no idea whether the flash is actually going to provide enough light or not, so it does something like just meter ambient light and tell me about exposure based on that. No surprise, there's not enough! I have learned to ignore the indication so thoroughly that I didn't even think to mention it until now.

My old Pentax TTL equipment had the same issue. But it provided an after-the-exposure indication by beeping a couple of times if the exposure had actually been OK. (Beep twice if and only if TTL quenched the strobe.) I don't think my Digital Rebel does that, but of course its LCD screen tells the story. Check your manuals and see if your film system does something like the beep indicator. If I recall correctly, the beep actually came from my Pentax strobe, and it was also controlled by the power switch: off, on with beep, on but quiet.

--Rik

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GreenLarry
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Post by GreenLarry »

the manual the manual, damn where did I put the manual.... :wink:

Thanks for the info guys.
Now a question, is there one of these TTL systems(TTL or E-TTL )that will only fire the flash if it can make a reading before making the exposure. Reason I ask is sometimes the flash wont fire when using the off camera cord(Canons own) and I thought I had a dodgy flash

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Post by rjlittlefield »

GreenLarry wrote:Now a question, is there one of these TTL systems(TTL or E-TTL )that will only fire the flash if it can make a reading before making the exposure.
Both systems should fire the flash at least once.

For TTL, that would also be the exposure that takes the picture.

E-TTL normally fires the flash twice -- a little one for metering and then a bigger one a small fraction of a second later to take the picture. E-TTL has enough information to hold off on the big flash if it's not going to be big enough, but that would seem pretty perverse and in any case you should be able to see the metering pre-flash, at least if you pay careful attention.

Does the strobe always work if it's mounted directly on the camera? Maybe a cable problem?

--Rik

(Sorry, no Digital Rebel info today -- I'm on travel and the camera's about 3000 miles away!)

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GreenLarry
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Post by GreenLarry »

I'll have to dust it off and give it a go.

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GreenLarry
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It seemed to work!

Post by GreenLarry »

Well, I had a go Friday night. I took some photos of a flower and a fern at lifesize, using the TTL flash, which worked fine!

Will have to wait a while to see the results tho as this is film, and i have a lot of it unprocessed!

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