QTB 7500-A Not so dedicated flash . . .

Canon Fan · Sep 27, 2004

I have a Quantaray QTB 7500-A flash that my wife bought for me about two years ago. Either I don't understand it or it is not working properly. The camera only ever seems to know that the flash is present and turned on but has no control over it other than firing it. I have had to resort to figuring all flash exposures with this unit manually. None of the program modes work correctly and since I do not have the GN# for it even manual is quite the experiment. Also the range/aperature chart seems to be quite misleading. Why does the TTL not function? I have tried it on my film Rebel 2000 as well as my EOS 10D same results. What am I missing here? Am I an idiot or will this flash only ever work in manual modes?

Canon Fan · Sep 27, 2004

PS- I will be buying a Speedlight 550EX as soon as I can afford it but this is all I have for now

ksmattfish · Sep 28, 2004

I've used a lot of TTL flash rigs, and I've found them to be lacking. Try using it on manual with the aperture chart on the back, but set the ISO to 1 stop slower than you are actually shooting. See how this works.

Canon Fan · Sep 28, 2004

I'll give that a try. Does the ISO slider on this flash unit actually even effect flash duration/power? Just doesn't seem like it does

bshearer · Sep 28, 2004

Your flash is very very similar to my promaster flash that I have, based on the looks (both front and back) I would guess they are the same (-minus the module on the bottom as yours is nikon and mine is pentax)

HERE is a link to the promaster flash

And HERE is a link to the manual for the FTD 5600.

I have no idea about how to use this flash, Im a hobbyist and trying to learn how to control constant light still, let alone trying to control and guestimate the results and adjustable variance of a flash.

ksmattfish · Sep 28, 2004

Canon Fan said:
I'll give that a try. Does the ISO slider on this flash unit actually even effect flash duration/power? Just doesn't seem like it does

No, the slider is just a GN (guide number) calculator for helping you figure the math. Set the calculator on ISO 100, and then multiply distance to subject times f/# and you'll have the GN (ISO100/feet). But sometimes it seems to me that manufacturers overestimate the power of their flashes by a stop or so.

Canon Fan · Sep 28, 2004

ksmattfish said:
But sometimes it seems to me that manufacturers overestimate the power of their flashes by a stop or so.

I would have to agree with that. However this one seems to be very underrated at close distances! I get major blow out all the time at distances of 15ft or less when following the chart. Oh well, work in progress I suppose.

Canon Fan · Sep 28, 2004

bshearer said:
Your flash is very very similar to my promaster flash that I have, based on the looks (both front and back) I would guess they are the same (-minus the module on the bottom as yours is nikon and mine is pentax)

HERE is a link to the promaster flash

And HERE is a link to the manual for the FTD 5600.

I have no idea about how to use this flash, Im a hobbyist and trying to learn how to control constant light still, let alone trying to control and guestimate the results and adjustable variance of a flash.

HA! Ureeka! Yes that is the exact same thing, and same manual that came with mine that has since been lost! This should help, thanks much. I've tried searching the web for info on the QTB and either I suck at searching or there is just nothing out there. I'll try this stuff for now.

Canon Fan · Sep 28, 2004

Um, well what can I say? I found a heck of a deal on a Quantaray PZ-1 TTL flash unit with off shoe cord on Ebay for $75.00 I know it's not a 550EX by any means but seems to be much better than what I am using now (besides I won't be able to afford the EX for quite awhile) Plus the added bonus of the off shoe cord which will work nicely with the stroboframe I will be getting next month.

So the question has now changed, what type of results should I expect with this flash and just how usefull is the LCD data-back?

usayit · Sep 28, 2004

Don't think that flash will work with canon digital slrs like your 10D. TTL flash is different from E-TTL which is available in canon's EX line.

Canon Fan · Sep 28, 2004

It will work, just not in full auto mode, which as I read today is the reason for the QTB being unresponsive also. From what I understand it will work in TTL mode but not E-TTL. Also the remote slave trigger function will not function properly when using the onboard flash to fire it (because of the initial metering flash from the camera)

However, the bonus I feel I will get from this unit is the auto-zoom head, flash strobing program mode (special effect I know), and more accurate readout of the power level setting (on the flash) and I won't need to remember to adjust the head position (being redundant). Plus I got a free off-shoe cord which is worth a good 30-40$ I would assume.

I'm not afraid of manual flash I just felt much more "in the dark" about it with the QTB (pun itntended :lol:

) and even if I do experience some problems I still think I got a decent deal on it and should have a bit more control with this one.

If not and I don't like it? Well I guess it'll be up for sale in the classifieds here! :lol:

The question I have though is if this unit will work with my Rear Curtain Sync command?

Canon Fan · Oct 4, 2004

OK well I didn't realize that this flash would not even fire! Not even in full manual mode. Why the heck will my el-cheapo QTB work with the 10D but the PZ1 won't even fire?!?! I thought it would at least work in manual. The auto zoom head does work just fine but no flash ready light in the viewfinder and will not trigger the flash to fire under any circumstances. I assume this IS the E-TTL messing it up but why does the QTB fire then?

Am I screwed forever into shelling out big bucks for the 550? Or a 420?

PS- The flash does seem to work fine on my Rebel2000. In any mode and fires perfectly

BTW sorry for sounding a little pompus there usayit