Light meter question

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OK, so I bought my first light meter and started to play with it. Set my SB-800 and SB-600 to manual (CLS) and fired them off at the meter. It read what you see in the picture. So I set the camera to those settings (ISO 100, SS 1/100, F2.0) and this picture is what I got. I think this is clearly overexposed.

So my question is...why?

Flash%20Test-003.jpg
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Did you have a square blinking around the flash symbol (lightning) on the meter when you took the picture with the flashes?
 
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I cannot tell from the posted image if there was any other lighting in the scene, but ideally you should be using a shutter speed that will avoid recording any ambient light as the meter is likely to be affected by this ambient light if it is strong enough.

I think that you should try a series of images at varying shooting distances to judge if exposure off overall and I would also suggest that you use the highest flash sync speed your camera offers to avoid the meter taking into account the ambient light. Not a bad idea to try in a semi darkened room first?

If you find that you are getting consistent overexposure then you may want to consider calibrating your meter - I think it will have a calibration adjustment function.

EDIT: Just a quick question as I do not own this meter. On the top left of the meter display next to the battery level there are three symbols which I guess are (L-R) Ambient light and two flash symbols. I guess that the two flash symbols are for cordless or corded flash? Your image suggests that none of these options has been selected as none are highlighted in anyway - maybe it is just that selection flashes on an off. If not and the selection should be highlighted then this may be the problem? I know that the question was asked and answered but I would have thought that the actual selection should be highlighted. Just a thought FWIW
 
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Roscoe,

Try reverse engineering it?

If you have two flashes with CLS try taking a portrait of someone (TTL) using Flash Value Lock on the face until you get a properly exposed image.

THEN introduce the Flash Meter in front of the sitter's face and see what you get?

DG
 
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Do you have the dome slid in the correct positon so your not getting a reflected meter reading?
 
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OK, so I bought my first light meter and started to play with it. Set my SB-800 and SB-600 to manual (CLS) and fired them off at the meter.

I'm not familiar with the meter. But are you sure it's not metering of the CLS preflash? That would be a fairly dim flash, causing the meter to return an exposure that will greatly overexpose when using the "real" flash.
 
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I'm not familiar with the meter. But are you sure it's not metering of the CLS preflash? That would be a fairly dim flash, causing the meter to return an exposure that will greatly overexpose when using the "real" flash.

Good call Lurker,

A possibility!

My suggestion re: Flash Value Lock would obviate that problem.

DG
 
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OK, so I bought my first light meter and started to play with it. Set my SB-800 and SB-600 to manual (CLS) and fired them off at the meter.


The Commander is incompatible with all manual stuff, including a flash meter. Simply different systems, incompatible. Just use real Manual mode everywhere.

It is not just the preflash from TTL remotes, but the commander flashes commands before the shutter opens (any mode). The meter will meter what it sees.

If you need the internal flash to trigger the remotes, then
put the remotes into their SU-4 mode (a simple optical slave), (SB-600 does not have it, but can be added, see http://www.scantips.com/lights/slaves.html )
and set the camera flash to Manual (real Manual mode at E3) at lowest power. That would work. This can be metered.

Or... complicated and convoluted... but ...

The flash meter has an infrared filter, to only meter visible light the camera sees.

The internal flash puts out both visible and infrared. You COULD (not suggesting, only the principle).. you could add a Nikon SG-3IR infrared shield on the internal flash (or use SU-800 infrared commander), so mostly, only infrared gets out (no visible light). That still operates the remotes, their sensor is filtered anyway, for only infrared. The flash meter is filtered the other way, only visible.

No filter is perfect, and there is leakage, but if the flash meter is at least maybe 5 or 6 feet from the commander, it can work then too. But you gotta really be hard up to be interested in such kludges. :smile:


It's against my nature to promote this in any way, I think we ought to use proper gear (manual ways to trigger manual flashes, if we are using a manual flash meter). But I could be a little more complete. As is, no filter, if you set the flash meter to a long shutter speed, say 1/2 second, even if your exposure will use 1/200 second), it will sample all of the light for this longer time. That is time enough for the commander signal, and then shutter opens, and then the final flash. That can work too (for Commander Manual mode, assuming a healthy powerful flash level). However, it is Not the same as a good plan. It will also pick up 1/2 second of ambient, some of this stuff not present in your 1/200 second picture.
 
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Thanks for the advice...but apparently FV lock doesn't work with external flash in M mode (of course, we all know how clear camera manuals are :smile:). The manual says that at least one channel has to be in TTL mode. So I set the pop-up to TTL and -3.0 to keep it out of the picture best I could (and the lock icon finally appeared in the viewfinder). Still metered way to low. I had to go from 2.8 (metered) to 5.6 just to get something close to right.

I have no idea what's going on, maybe the meter memory is too long and won't forget the preflashes.

Any ideas? I wasn't planning on triggers anytime soon but looks like I have no options left.

<sigh>
 
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I am not sure of your goal, but right, FV Lock is about TTL, and is not about M mode. FV Lock triggers the TTL preflash then, and meters it then, and later applies that remembered exposure to the next shutter release for TTL mode. FV Lock does nothing in Manual mode(s), which is why manual says there has to be at least one TTL group. There is nothing for it to do in Manual modes. FV Lock does not affect Manual mode flashes. Manual Remotes use the power level from the Commander menu (which is sent at every shutter button).

Because, there is no TTL exposure to be metered in Manual mode. Manual is however you set the lights power level yourself (perhaps with the handheld meter), or in the case of Commander, however you set the manual power level yourself in the Commander menu. You can of course press the FV Lock button with manual, but nothing happens (commander does not flash request for TTL preflash to be metered).

To disable the internal flash with Commander, just set the Internal Group to mode "- -" in the Commander menu. That disables the internal flash (will not contribute light for the picture), but it still works as commander, which still flashes commands to the Remote flashes (including menu manual power level sent to remote flashes).

But the handheld light meter for Manual ain't gonna work with the Commander, except maybe with one of the kludges mentioned. The light meter will just meter the commander signal to transfer the manual power setting from the commander menu, before the shutter is open. The meter meters that, instead of metering the final flash (unless the kludges).

Commander is its own system, with its own ways, and is totally incompatible with all genuinely real Manual mode flash gear. We should choose one or the other system, Commander or Manual gear.
 
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Roscoe,

My suggestion about using FV Lock was made so that you could reset the meter between the pre flash and the main flash.

I take your point about Manual Flash and FV Lock - I don't use that combination:smile:

Hope that makes sense?

DG
 
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My suggestion about using FV Lock was made so that you could reset the meter between the pre flash and the main flash.

Except that FV Lock won't help with the handheld meter. It does prevent pictures of the subject blinking from TTL commands and preflashes.

Commander signals (flashes from camera) include:

1. Command flash to each TTL group in turn to request TTL Preflash. Each TTL Remote complies in turn, and its preflash is metered. FV lock button does this when we push it, and it locks it (remembers it), and if locked, this is skipped at next subsequent shutter button(s).

Groups in Manual flash mode does not need or do any of that (their power level is already known, in the Commander menu). FV Lock does nothing (inactive) for Manual groups.

2. At any shutter button (FV Locked or not, TTL or Manual, every shutter button), the Commander flashes a command to each group to convey TTL or Manual power level to the remote. This occurs immediately before shutter opens (too quick for the subject blinks to respond). It seems to also be an encoded signal to enable the remote flash, and there is a milliseconds time out preventing any other flashes from triggering it later.

Anyway, FV lock does not affect this. The commander flashes immediately before shutter opens, in every case. The handheld meter will meter this, instead of the following full flash.

A handheld flash meter is a Manual flash technique. Commander is anything but Manual flash, even in its manual power level mode. Commander is its own system, simply incompatible with real Manual flash gear and techniques. We really need to choose one or the other systems, and go with it. Either system can work great, but mixing them is bad news. Never what anyone wants to hear.
 
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Wayne, everything you say jives with my understanding of the system, thanks for that. Time to look for some triggers...or learn to use the CLS without a light meter.
 
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You could solve the problem for maybe about $15.

The SB-800 has its SU-4 optical slave mode, and it is an exceptionally fine one.

The SB-600 does not, but you can add one from Ebay for maybe about $15.
Maybe not any one of them there, but some of them:
See http://www.scantips.com/lights/slaves.html

Then you can set the camera flash to Manual mode in E3 menu (Not Commander), and set its power level to (probably) Minimum power. This is about the same low trigger flash the Commander would have done.

Set them out there and meter them in this Manual mode (SU-4 Manual).

Should work fine.
 
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We really need to choose one or the other systems, and go with it. Either system can work great, but mixing them is bad news. Never what anyone wants to hear.

That, I agree with.

The Op's mixing of CLS and the use of a Meter is confusing.

I am a firm believer in the capabilities of the CLS system and usually, if it does not give the expected result, it is my selection of the point on which to FV Lock that causes the problem.

We have a great meter within the camera (the Histogram) with which to judge exposure.

Take a test shot = Take a meter reading.

I must put a battery back in my old Flash Meter and prove you right Wayne:smile:

DG
 
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That, I agree with.

The Op's mixing of CLS and the use of a Meter is confusing.

I am a firm believer in the capabilities of the CLS system and usually, if it does not give the expected result, it is my selection of the point on which to FV Lock that causes the problem.

We have a great meter within the camera (the Histogram) with which to judge exposure.

Take a test shot = Take a meter reading.

I must put a battery back in my old Flash Meter and prove you right Wayne:smile:

DG



Roscoe is using manual flash levels though, so the camera meter is of no use then, it only works for TTL. Nikon provides no means for metering manual flash, but manual flash has a lot of advantage in the studio (control). The histogram does work fine with ONE flash, but it cannot set relative levels of multiple flashes. Fill at one stop down from 255 ought to be around 187 (73%), but this varies in the camera (settings for white balance, contrast, etc)

It's of course very natural to want to use the handheld flash meter for manual flash, but it's a hard road when the commander gets in the way.

Filtering the commander is one kludge, and using a longer exposure in the meter is another. Simply turning Commander off, and using a manual system is by far best (assuming manual flash).

For manual levels, the commander is only used for a trigger.

There are other trigger methods that do work, the inexpensive optical slaves for example (some flashes already include this). Both optical ideas can have similar limitations, direct line of sight, sunlight, and from the internal flash, a weak trigger flash that conceivably could slightly affect the picture lighting from that direction (catchlights in eyes sometimes).

Commander has one advantage of setting flash power at the camera. Otherwise we have to walk to each manual flash to set power level. But my own rooms are not all that big. :smile:

But if multiple flashes, the internal flash only has to trigger the near one, with lowest possible level (or any other method could trigger this first one). And then it triggers the other slaves, in sync, with full working power, which bounces off walls very well, no longer line of sight. In that way, normally optical slaves normally are simply no issue at all indoors, even when hidden behind subject, etc.
 
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Where's a good website that explains how to use CLS? For example, if I have one flash set as Group A for Key a second set as Group B for fill (both TTL), what levels do I set them at? What mode do I put the camera in?

Manual mode I understand (just physics), this automatic figure-it-out-for-you TTL stuff is confusing.
 
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TTL ... any camera mode, A, S, P, or M. Camera M is only manual with respect to the continuous ambient... Outdoors in sun, unless using a handheld meter, you probably want P or A, since we cannot ignore the sun, it overwhelms, must be dealt with.

But indoors, we hopefully can ignore ambient, and I almost always use camera M, so I can control the ambient (get rid of it) with fast shutter speed (near Maximum shutter sync speed, for no orange incandescent). But use any camera mode for TTL.

Camera A would be next choice for flash, but it will always use 1/60 second with flash (default, there are limited options, menu E2).
M mode simply means you can set any shutter speed.
Flash does not care what shutter speed is (ambient does).

In TTL, you do not assign levels. Automation does it. You only put the flash into Remote mode, the hot shoe foot goes dead, and then EVERY control is in the Commander menu (not on the flash). There is no Standby, don't leave it on overnight.

The TTL flash is still fully automatic flash in any camera mode. It simply responds to whatever ISO and aperture it discovers is in play, however it got that way. Then it does its thing. If you change ISO or aperture, it won't change exposure, since automation it will simply respond to the new situation. TTL is automatic flash.

Flash Compensation is how we control TTL, to get different desired results... more or less flash.

Groups. Ideally, you put each flash into a different group, A or B, so they can be metered and controlled individually. In the same group, they act as one flash.

Here is the thing: In different groups, TTL will meter them and will set them all Equal at the subject (flat, no ratio). Equal no matter what, distance, modifier, direct/bounce, etc.. If they have enough power capacity to do it. With Remotes, it is good to set the Ready Warning to beep, so you will know. The viewfinder Ready is just guessing then. Commander is all one way TO the remotes, nothing comes back.

This Equal at the source metering is a starting point. But you also can specify group Compensation in the Commander menu groups, maybe to set Fill to -1 EV, or -1.7 EV, for ratio (its often a really good thing to do). And the commander will do that too. The menu A and B are of course the A and B that you assigned.

Normally, it is no surprise to discover Commander TTL needs more flash compensation because it is a bit underexposed (it is TTL BL). So instead of fill to -1 EV, and Main to 0, you might set Main to +1 EV, and fill to 0, which is same 1 stop ratio, but also +1 EV overall compensation. As needed, but that is good start.

Regular Flash Compensation works fine too, but it only has a +1 EV range. They add, so setting Main to +1 and setting FC to +1 is +2 (if the flash has power to comply).

But this is the beauty of Commander... point&shoot wireless multiflash, with ratio.

You can just throw the lights out there, and Commander will make them equal, and then offset them with your specified ratio. Its good to think about lighting though, as always.


My commander writeup is at http://www.scantips.com/lights/awl.html
I am just repeating. It should be all you need.
 
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WayneF, your site was spectacularly helpful. A little confusing at times, but after a couple of stop-and-goes it all made perfect sense. I'm still a little fuzzy on the need to set the TTL key light well above 0 but that was my experience as well so at least I know I'm doing it right :smile:

I've also figured out how to use my SB-800 in Optical slave (SU-4) mode. Now I figure I can get by with a simple 2-trigger (Tx-Rx) setup, using my SB-600 with the Rx and optically triggering the rest. Now I can play with my meter and compare the two techniques inexpensively. In short, you rock!
 

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