Nikon N80 SB-28 underexposure

[sundaram_venkatachalam1]

All my slides (Fuji Velvia) that I used with Nikon N80 and SB-28 DX

combo turned out to be dark (severely underexposed). Non flash pics

turned out well exposed.

 

I checked my batteries (they are fresh), Aperture Priority Mode -

lens completely open at 2.8 (35-70/2.8D), flash set at TTL Matrix,

camera metering set at Matrix Metering, no camera or flash

compensation, subjects within 8 feet, film speed set at DX, Stofen

Omnibounce (not tilted).

 

Can anyone help me?

 

I'll try and scan the slides and post them.

 

--Sundaram Venkatachalam.

[arnabdas]

Were you shooting indoors? If so, try with standard TTL flash.

 

These electronic AF cameras continue to amaze me. Such a steep learning curve ...

[hal_bissinger]

No Arnab, that's not the problem.<p>

Sundaram, either the settings are not as you say or there is a problem with either the flash or camera. There is no reason for the underexposures otherwise.

[armando_roldan]

Aperture Priority Mode - lens completely open at 2.8 (35-70/2.8D),

 

perhaps your shutter speed defaulted to higher speed than what your flash sync is. You were shooting WIDE open and the shutter might have gone to 1/500 or 1/1000 of second duration

[sam_portera]

I get underexposed pics when I use my N80 and Sb28 in TTL matrix mode when the on camera flash is the only source of light. Use standard TTL it did the trick for me.

[musubi1000]

Try checking the ASA setting on camera. Sometimes with the DX auto setting the speed sometimes changes.

[sundaram_venkatachalam1]

In aperture priority, the shutter speed is capped at 1/60 sec - you can't go faster than that. However, I will check when I do my tests again.

[todd peach seattle, washi]

A couple thoughts come to mind:

Nikon tends to bias towards flash underexposure (at least on the combinations of N90/N90s/F100 - SB-25/26/28DX that I have shot); this coupled with the 'matrix balanced fill flash' modes usually gives a more 'subtle' feel to the flash. With a 'narrow' film like Velvia, I would not be surprised to see this underexposure 'fall off the end of the earth'.

 

Second, the omni-bounce (not tilted). If you're using a light modifier on a Nikon flash, you're running the risk of mucking up the 'D' calculations. When you're using a flash straight ahead in a D system, it assumes it knows the distance and uses the GN of the pre-flash to determine if the subject is 'non-normal' reflectance (black or white instead of gray). When you insert a 'loss' in the flash path, the system doesn't know it. The system sees the pre-flash return 'dim', interpolates 'dark subject', then biases in underexposure to the main flash.

 

Note that when you tilt the flash head, it disables the D system.

 

There are folks who swear by the omni-bounce on Nikon D systems. When I have got into the details with them, they usually have some pretty specific opinions on "+1 stop" or something like that.

[Jerry_]

With indoor shooting, print film likes a little extra light, and the Nikon speedlight is made for out-door fill flash. One can regularly go up to +1 on the exposure compensation (large or small spot meter) and get decent prints.

 

 

With slide film, this does not happen. The exposure has to be 'on the money' or you get results that are not going to please you. Suggest you take notes, lose the flash modifier for your test shots, and try the camera in 'M' mode for a few shots with dead-on flash.

[Carl Stone]

Here's an example of NPH 400 shot @ ISO 320 with an SB-28DX and omni-bounce

not tilted, in TTL matrix fill mode, with a D lens. As Todd says, "subtle" fill flash.

[angel_o.]

Actually, it should work perfectly. I first thought that maybe you're too far away, but 8 feet at F/2.8 aren't nothing for an SB-28.<br><br>

I guess that you have a problem, either an electrical problem, a camera failure or a flash failure. Have you tried cleaning the contacts of the flash and camera? The next thing I would do is changing the batteries of the flash and the camera (at least, take them out and reinsert them -> sort of an hw-reset) and trying again without the omni-bounce. <br><br>

BTW, you should check that the settings of the camera are transmitted correctly to the flash (ISO, aperture, focal lenght, 3D-TTL symbol: the one with the four sectors and the dot in the center)<bR><br>

Good luck!

[bruce_rubenstein___nyc]

I have the equipment you have. Todd Peach has been the only one to give your the right answer: you can't use an Omni Bounce, without tilt, in 3D Matrix mode because of the D pre-flash. The pre-flash can be turned off by: tilting the head, setting the flash to plain TTL or setting the flash mode on the body to rear sync. (You have to do the same thing if you want use a flash meter.)

[Carl Stone]

"I have the equipment you have. Todd Peach has been the only one to give your the

right answer: you can't use an Omni Bounce, without tilt, in 3D Matrix mode because

of the D pre-flash"

 

That certainly is NOT true of the F100 using the SB-28DX and an Omni-Bounce. See

my post above yours where I included a photo doing exactly what you said wouldn't

work.

[todd peach seattle, washi]

Hey Carl -

 

Are you sure that shot was with the omnibounce in place? It's a lovely shot, but my reading of the shadow edges (under hat, arm) tells me it was a harder light than what I would expect from an omni at that range.

 

I do like to defer to people who are actually making a technique work for them, but I still feel compelled to dredge up the 'theory of operation' when trying to figure out why a user is getting bad results.

[Carl Stone]

"Are you sure that shot was with the omnibounce in place?"

 

Yep, I'm positive.

 

"It's a lovely shot, but my reading of the shadow edges (under hat, arm) tells me it

was a harder light than what I would expect from an omni at that range."

 

You're right about the shadows, but remember the Omni was pointed straight ahead,

and shadows were expected. What I wanted to find out, since i just got the flash unit,

was if I was going to get that tell tale hot spot, and I didn't. So, aside from the

shadows, the light was subtle on the subject. I probably should have taken a few

more shots with the flash arced up, and with the bounce card out. That would have

given me more info that I could use. The problem was that I wasn't alone, and those

folks didn't have the patience to wait while I took a few more shots. Still, it does show

that an Omni can be used straight ahead with a D lens.

 

 

"I do like to defer to people who are actually making a technique work for them, but I

still feel compelled to dredge up the 'theory of operation' when trying to figure out

why a user is getting bad results."

 

To be fair, there are some differences in what I did, For one thing I wasn't shooting

Velvia, but a faster film. And I wasn't using an SB-80DX, that may or may not effect

the shot. One of the things that I like about the 28DX is the battery saver feature, and

you can just leave it turned on all of the time. However, your memory should be

better than mine, if you do this, because sometimes you don't want the flash.

Included is a shot where I forgot that the flash was turned on, and it ruined the shot.

My pencils have an eraser just as big as anyone else's, LOL.

[angel_o.]

<i>"...you can't use an Omni Bounce, without tilt, in 3D Matrix mode because of the D pre-flash..."</i><br><br>

While I don't own an Omni Bounce, I would like to understand why the pre-flashes can't go through it and allow a proper exposure at three feet. IMO, if the Omni Bounce is not tilted, it shouldn't have any strong effect on the quality of the light except throttling the light-output. <br><br>

Can someone explain why proper 3D-TTL exposure is possible with the SB-28's "on-board" diffuser and not with the Omni Bounce? What's the magic behind it?<br><br>

Thanks for your explanation!

[Carl Stone]

The Omni-Bounce does not cover the pre flash. Some other diffusers, such as Lumi

Quest, do block it.

[todd peach seattle, washi]

OK, now I'm confused, Carl. Are we talking about the same StoFen Omnibounce?:<br>

<a href="http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=52696&is=REG">http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=52696&is=REG</a>

<p>

This should indeed cover the pre-flash (or at least filter it). Maybe I'm missing something.

<p>

The difference between this and Nikon's own diffuser is that Nikon's diffuser is 'known' to the flash unit. When you deploy it, the calculator in the flash shifts gears. The StoFen is an 'unknown'.

<p>

Nothing to do with diffusers, but the attached photo (which also 'headlines' our personal website) was done by a stranger with my N90s/SB-26/35-70 f/2.8. Everything locked down on program, AF, 3DMBFF. Subtle flash fill, but you can still see the hard edge shadow from my wife's arm on my chest (he held the camera the 'wrong way up' for verticals, but I can't argue with the results). Best shot from that trip, and a stranger did it!<div></div>

[Carl Stone]

"OK, now I'm confused, Carl. Are we talking about the same StoFen Omnibounce?:

http://www.bhphotovideo.com/bnh/controller/

home?O=productlist&A=details&Q=&sku=52696&is=REG "

 

Ayuh, that's it.

 

"This should indeed cover the pre-flash (or at least filter it). Maybe I'm missing

something."

 

Now you have me curiuous, and maybe I'm fulla sour owl crap. But, it's my

understanding that the main head is not used in monitor pre-flash.

 

"The difference between this and Nikon's own diffuser is that Nikon's diffuser is

'known' to the flash unit. When you deploy it, the calculator in the flash shifts gears.

The StoFen is an 'unknown'."

 

 

Yes and no. I'm not sure that it's an unknown to the SB-80DX, since that unit comes

with that diffuser. What I did was use the drop down diffuser AND the Omni-bounce,

for sort of a double diffusion collusion. :o)

 

"Nothing to do with diffusers, but the attached photo (which also 'headlines' our

personal website) was done by a stranger with my N90s/SB-26/35-70 f/2.8.

Everything locked down on program, AF, 3DMBFF. Subtle flash fill, but you can still

see the hard edge shadow from my wife's arm on my chest (he held the camera the

'wrong way up' for verticals, but I can't argue with the results). Best shot from that

trip, and a stranger did it!"

 

Don't be too critical, that is a nice shot. Another point to remember is that P mode is

pretty darn good in today's Nikons. Besides, without additonal lighting to chase away

those evil shadows from the flash, your stuck with what you got. Nice overcast day,

were you at Multnoma Falls?

[todd peach seattle, washi]

<i> it's my understanding that the main head is not used in monitor pre-flash. . . .

Yes and no. I'm not sure that it's an unknown to the SB-80DX, since that unit comes with that diffuser. </i>

<p>

Yeah, the inclusion of the StoFen-like device with the 80DX surprised me, but I figured that with the 80DX they added some kind of micro-switch to sense that the diffuser was there. I have been under the assumption that the monitor pre-flash *was* a main head thing, so that it was subject to the same angle of view, etc. I thought the little lights were for modeling, red-eye or some-such.

<p>

I've only used the 80Dx for a 'borrowed' weekend with a D100, and I didn't bother with the omnibounce thingy.

<p>

<i>Don't be too critical, that is a nice shot. Another point to remember is that P mode is pretty darn good in today's Nikons. Besides, without additonal lighting to chase away those evil shadows from the flash, your stuck with what you got. Nice overcast day, were you at Multnoma Falls?</i>

<p>

Yes, we like it. The 'critical' part was that I didn't shoot it! It was 'cloudy bright', and the sun is over my left shoulder (check the highlights on the shoulders, hair). The location is Steamboat Springs Colorado, a vacation for us.

[Carl Stone]

"Yeah, the inclusion of the StoFen-like device with the 80DX surprised me, but I

figured that with the 80DX they added some kind of micro-switch to sense that the

diffuser was there."

 

My assumption also. Especially since the 80 defaults to 14mm with the diffuser

attached. That must bring the head forward irrespective of the focal length on the

lens. Although I would expect a wider dispersion with any sort of diffuser.

 

" I have been under the assumption that the monitor pre-flash *was* a main head

thing, so that it was subject to the same angle of view, etc. I thought the little lights

were for modeling, red-eye or some-such."

 

Well at least one of us is right, LOL. Hopefully someone with better knowledge posts

the correct info. I'd really like to know for sure, so that I don't continue down the

wrong road.

[angel_o.]

<i>"Yeah, the inclusion of the StoFen-like device with the 80DX surprised me, but I figured that with the 80DX they added some kind of micro-switch to sense that the diffuser was there." </i><br>

<br>

It's really quite interesting to recognize how complicated this flash system is and to see how well it works.<br><br>

Thanks for your patience!

[jay_lorenzana]

Make sure your not on 3d matrix balanced FILL flash. It's for fill.

 

I've also noticed underexposre in std ttl mode when shooting indoors. With a flash meter my N80/SB28 works best w/ flash comp set to +1.5. I shoot wedding all the time works perfect.

 

When I bought the camera I was totally dissatisfied w/ the flash till I got my flash meter to really measure what the damn thing was doing. I too thought it was broken, wanted to bring it in for repair but i've learned to live w/ it and set +1.5 (@ f/4.5 - f5.6, don't normally go down to 2.8 so not sure what the comp for that is). Also with this setting the thing is right on w/ any bounce/stofen techniqe.

 

Good luck, jay

[andy_phatana]

This forum was give me loads of information.Thanks.I used D1 and sb80dx and 35-70 f2.8 af non D.I found problem with under and over explosure all the time.

But with digital I just retake it till I like it.I have to live with it due to Non True TTL on D1.What annoy me.That you miss the moment with under or over explosure.I didn't have all this problem with my film camera N90.Thanks again for all this information.

andy