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I promised to do a battery test similar to the one Glen did in this post
http://www.dslrusers.com/viewtopic.php?f=17&t=31955&sid=58257084446f5510a95e583e181b67b2

After refresh-charging one set of Imedions, and using another out of the pack, I set up one of my SB800 on the hotshoe of my D200. I set Camera to ISO100, Manual, Flash WB 1/250, F9. I put the just charged Imedions in the flash and set it to M 1/1 17mm. Then I set the camera to fire repeatedly every 20 seconds. I came back about half an hour later to check on it. The flash was indicating Ready almost immediately, but the exposures were way down. Strange. I went back over the photos & discovered the power drop happened suddenly after only 11 photos Not good for a brand new, fully charged set of batteries of any description. I tried the flash in TTL mode & it worked fine. I tried another set of betteries & it worked fine. I tried the new batteries in another flash, and they worked fine. I tried them back in the original flash & they still worked fine. I checked them in a battery tester & they read almost fully charged.

So I tried the same setup with the out-of-the-pack Imedions in my other SB800. Same result, this time after 43 photos.
I tried a Flash reset. No joy. I tried taking the batteries out and putting them back. No joy. I changed the batteries. Working again. I put the first set back in. Still working.

Neither batteries nor flash felt unduly hot, so I don't think it it was a thermal cut out ALso ambient was about 9 degrees, so I would expect more life than this. Also both worked fine in TTL mode, but not M mode.

Can anyone suggest what might be going on. It is affecting 2x SB800s and 2x sets of Imedions ( at least!) and its driving me crazy

Greg,

What was your target subject for these images? Was there perhaps something there that may have been interfering in some way?

Hi Greg, So as to eliminate variables one at a time, are you seeing poor results in every day use, or only when using the test setup you describe?

Camera was set to fire every 20 seconds Flash was tilted approx 15 degrees from vertical (i.e. mostly bounce but a little direct light)
Flash was mounted on camera & set to M 1/1 You can get everything else from the EXIF
THe room was dark (night & no light on) The door was open so I could see the flash firing, but it was at the end of a long hall, so there would not have been any ambient leakage.

First image in set

Last good image in set

first bad image in set this is the very next image taken after the one above

The flash was firing but VERY weakly (the ready light came back on immediately) The sequence continued for about 330 photos before I went into the room to check on progress.

I have not noticed this behaviour except in this test
These are all from the second group of photos (the out of pack batteries). With the earlier set, the drop off was not as severe (it was as sudden), but I did not keep any of that group (formatted card in camera)

Greg,

Off the wall thought: there have been reported instances of SB800s misfiring when used with a D200. Is that perhaps an issue that you may be seeing? It only requires a mistiming of a poofteenth of a second to totally miss sync; when you look closely at the bad images, is there any indication perhaps of misfiring or mistiming?

A poofteenth of anything is my very favourite measurement.

Off the wall thought: there have been reported instances of SB800s misfiring when used with a D200. Is that perhaps an issue that you may be seeing? It only requires a mistiming of a poofteenth of a second to totally miss sync; when you look closely at the bad images, is there any indication perhaps of misfiring or mistiming?

I WAS wondering about mistiming, but I don't think so. At least that is not the whole problem. It may be mistiming, but it is also misfiring (i.e. wrong power).
When the flash goes off for a normal shot it lights up the hallway. When it misfires, it barely raises a flicker in the hallway.

I am doing another test as we speak. To add to the puzzle, if I change to TTL for one shot within the 20 sec window, it fires OK (exposure is different, but that is to be expected. Going back to M, again within the window, it fires properly again. No time for the flash or batteries to cool down. No change of batteries, just toggling to TTL for one flash and back. Last night I tried toggling to another setting and back without firing. It did not fix the issue.

EDIT: I will try with the same flash and Pam's D70s, but that will have to wait till next week. We are about to head off to Sydney for the AW (among other things) We won't be back home till next Tuesday or so.

Hi Greg, very unusual. In my tests I usually experienced a low exposure one or two prior to a full black expopsure. Often I would then get good exposures later. I think the TTL issue is just the batteries recovering (and of course TTL is likely to be a lower power than full manual). The two biggest points of difference between your test and mine is the 9 degree ambient temp (I didn't measure mine but would have been 18-23 as I was just wearing a Tshirt) or as Gary said, D200 v D300. I am happy to test your batteries and send you mine if that helps.

Greg,

Mr Darcy wrote:When the flash goes off for a normal shot it lights up the hallway. When it misfires, it barely raises a flicker in the hallway.

Which suggests to me that this is not a (mis)timing issue then.

You said you're shooting at 1/250? Could you try 1/200 or 1/125? I don;t expect it to make any difference, but it may be worth a shot.

Also, have you properly secured (and clamped) the SB800 in the hotshoe?

I will try with the same flash and Pam's D70s, but that will have to wait till next week. We are about to head off to Sydney for the AW (among other things) We won't be back home till next Tuesday or so.

Bring the D200 and SB800 with you; we may be able to run some quick tests for you tomorrow evening, as well as run against different SB800s and different bodies.

Glen wrote:Hi Greg, very unusual. In my tests I usually experienced a low exposure one or two prior to a full black expopsure. Often I would then get good exposures later. I think the TTL issue is just the batteries recovering (and of course TTL is likely to be a lower power than full manual). The two biggest points of difference between your test and mine is the 9 degree ambient temp (I didn't measure mine but would have been 18-23 as I was just wearing a Tshirt) or as Gary said, D200 v D300. I am happy to test your batteries and send you mine if that helps.

Yes the TTL flash is lower power than the normal M 1/1. I have set the exposure spike right to the right of the graph for the manual exposure. There is a lot of white wall after all. The TTL one puts the spike in the middle of the graph.

BUT

Last night I had over 200 misfires in a row. That is lower power than the TTL shot. If battery recovery was an issue, it would have come back.

D200 vs D300 is more likely to be an issue. I will test again with a d70s

This is more of an annoyance than a real issue. I can't think of a real world circumstance where I would want to fire more than 40 M1/1 flashes 20 sec apart. I just can't do the battery test I promised. I would also like to know what is going on as that's the way I'm made.

Also, have you properly secured (and clamped) the SB800 in the hotshoe?

YES

You said you're shooting at 1/250? Could you try 1/200 or 1/125? I don;t expect it to make any difference, but it may be worth a shot.

Will do. EDIT: Tried. Flash failure showed up again. Same sequence cured it.

Bring the D200 and SB800 with you; we may be able to run some quick tests for you tomorrow evening,

Will do and a tripod

as well as run against different SB800s and different bodies.

I have two SB800s both exhibit the behaviour.

As a simpleton, I would assume that the flash is not designed to fire at full power so frequently and continuously.

I would suggest that you try your procedure again, and, as soon as the failure starts, check the physical temp of both batteries and flash unit.

20 seconds seems ok, but, at full power for 330 shots seems like a high level of demand on the circuits of the flash.

Reschsmooth wrote:As a simpleton, I would assume that the flash is not designed to fire at full power so frequently and continuously.

I would suggest that you try your procedure again, and, as soon as the failure starts, check the physical temp of both batteries and flash unit.

20 seconds seems ok, but, at full power for 330 shots seems like a high level of demand on the circuits of the flash.

I agree this is a fairly extreme test, but I was duplicating a test by Glen using the same model flash.
He did not experience the same issue.

Also, We are not talking about 200 shots before failure. My first test, with absolutely fresh batteries started exhibiting symptoms after only 11 flashes. I would expect this to be well within the capabilities of any flash designed for professional use with repeat fire capability buiilt in. The longest run I have had has been 45 good flashes.

I have checked temp, but only by feel. I don't have a probe thermometer to hand. Neither flash nor batteries felt noticeably warm. The batteries did feel warm today after about 250 shots, mostly good. But I was still getting good shots out of them. See above for how I achieved this.

Gary, I will bring the CF card with me too. With the photos still on them.
Also I will be away from reliable internet contact now till Tuesday (I will try to get to a library to load WE07 shots on Monday)

Mr Darcy wrote:Also, We are not talking about 200 shots before failure. My first test, with absolutely fresh batteries started exhibiting symptoms after only 11 flashes. I would expect this to be well within the capabilities of any flash designed for professional use with repeat fire capability buiilt in. The longest run I have had has been 45 good flashes.

Yeah, well, given that you did mention that in your previous posts, you can safely ignore my post and try to get back the 45 seconds you spent replying

Yeah, well, given that you did mention that in your previous posts, you can safely ignore my post and try to get back the 45 seconds you spent replying

Clearly you have not seen my typing lack of speed

Running on a borrowed connection - very poor & unsecured wireless
One good thing about the city. I can see about 20 Wifi connections several unsecured. Sadly only low strength. At home I can't even see my own (SSID brodcast off)

I tried to test on the d70. Forgot it doesn't have interval shooting built in & forgot to bring the tethered shooting cable down to the city, so testing will stop until tuesday Damn. I will still bring gear to AWD.

Mr Darcy wrote:Running on a borrowed connection - very poor & unsecured wireless

There's another type?

Don'tcha just love default router setups?

gstark wrote:

Mr Darcy wrote:Running on a borrowed connection - very poor & unsecured wireless

There's another type?

Don'tcha just love default router setups?

yEP MY ONME AT HOME.

Now I am very confused.
I tried to duplicate my results at the AWD so the boffins could have a look-see. It worked perfectly. Don't you just love intermiitent problems?

I tried again at in my digs in Mosman:
63 photos good in a row. Temp 14C
50 bad photos then interupted
Batteries removed checked and replaced (flash not turned off)
Auto fire turned off for the period ( 2 minutes)
Autofire recommenced. System left Returned several hours later to find camera no longer firing – Camera battery dead (not surprising) Checking the photo log revealed 381 images all good I.e. over two hours continuous firing. FLash Batteries still not dead.

My best call is that this is somehow a temperature problem that manifests somehow when either the FLash o batteries or camera warms up from cold. It does not affect operation at reasonable temperatures, hence my good results at the AWD and mid morning the next day.

It is also interesting to note though that I managed double the number of flashes than Glen got once the day warmed up" I got over 450 M1/1 flashes in total from one set of batteries & they still weren't dead!

I will give up testing and just accept that the Imedions are very good, but perhaps not at <10C
(or it could be the flash circuitry)

Greg, it seems like you have pinpointed the only variable. Interesting difference between the temperatures, somewhat explains why cars don't start on cold mornings.

Out of curiosity, did you use the 5th battery on the sb800?

Regards
MATT

Out of curiosity, did you use the 5th battery on the sb800?

No I Didn't. When I started this excercise I was aiming to duplicate Glen's test as far as possible, so his and my tests could be compared as readily as possible.
He used 4 cells, so that's what I used.

It rapidly became a WTF test, but I kept to the original intent.

My real world aim was to find out how many cells I should carry to NZ for my daughters wedding. I will be living out of a campervan there, so won't have ready access to recharging
I think I have the answer now... as many as my luggage allowance will permit

Mr Darcy wrote:

as many as my luggage allowance will permit

Thanks for the reply and good luck..

MATT