Sekonic L-758 Flash Exposure

Hi just recently bought the 758 i'm new to using a meter and thought the 758 would check all the boxes i need...

Problem is, i have done a exposure profile for my camera using the seckonic dts sofware by setting up the camera profile using ambient light...... I have checked my cameras reflective meter with the 758 and it's comparable.. The problem i have is using the light meter using the speedlights it seems well over exposed, i dont really know what is wrong.. I know i can manually adjust the light meter and its about 5.8 stops over exposed...... I would love to hear from anybody who has experience with using the seckonicL-758.....The reason is i'm wondering if the meter is faulty??? Do i have to make a exposure profile for using the speedlights?? So in other words one profile for ambient light and the other for using speedlights?? Thanks for any help.. Andy..

Likely the meter is defective and needs repair shop attention...'calibration' should NEVER take 5.8 stops of correction!

Yes kind of what i thought, i will do some more experiments still not sure yet if it's something i'm doing wrong.. The calibration i did
using ambient light with the dts software was normal i think......... But a while i wasnt sure how to set up the light meter using flash so i folowwed a You tube video which didnt use the dts software it only used the grey card to setup the exposure, i found i had to manually adjust the meter to about 5.8 stops under then with flash it was ok.......But later i found out i should calibrate the camera and lens to the 758....and the only way i knew how to do that was using ambient light...... when i measure ambient light with dome out etc it measure similar to me my camera so it seems its working in the same ball park.. ..but when taking a flash test reading i input those readings to the camera take a flash photo and it's WELL OVER exposed.. I think it must be faulty but it's brand new i didnt know seckonic meters even went wrong...so i thought it must be me..

Faulty!?
That is most unlikely. And I speak from very long experience using the L758D. It is not faulty. It is you and/or YouTube, or errors in translating the skill set from YouTube to your own circumstances (which are at best, unknown at the present).
Film/digtal and flash/strobes do not require exposure profiling, and will not benefit from exposure profiling. A grey card is not required (but it is useful as an adjunct basal reading tool in multispot metering, altogether different).

Be aware also that the L758D reads 12.6% incident/invercone and 16.2% reflected (spot), and the two meter systems are exclusive of each other, e.g. the same reading cannot be transferred from incident to spot or vice versa. The variation of the two meter systems is not really significant in actual practice.

Your Spedlight must be set to baseline manual exposure and output, and manual sync of the camera. It cannot be set to full auto working with, or controlled by the camera and then have the L758D magically read the mind of the camers/flash! The L758D is primarily a measuring tool for ambient/artificial light and a mix of that, and for this it works very, very well. If the lighting mix changes each time, profiling will give very inaccurate results. This is the same for digital as it is for film.

There is insufficient information in your text as to what settings you have proceeded with to arrive at the spurious 5.8 stop.

Can you find someone near you, who has a flashmeter and who would take a reading with flash and also permit you to take a reading with your L758 to compare? Perhaps you are seriously misusing the meter and are not following Sekonic's detail documentation on meter use?!

Poisson Du Jour said:

Faulty!?
That is most unlikely. And I speak from very long experience using the L758D. It is not faulty. It is you and/or YouTube, or errors in translating the skill set from YouTube to your own circumstances (which are at best, unknown at the present).
Film/digtal and flash/strobes do not require exposure profiling, and will not benefit from exposure profiling. A grey card is not required (but it is useful as an adjunct basal reading tool in multispot metering, altogether different).

Be aware also that the L758D reads 12.6% incident/invercone and 16.2% reflected (spot), and the two meter systems are exclusive of each other, e.g. the same reading cannot be transferred from incident to spot or vice versa. The variation of the two meter systems is not really significant in actual practice.

Your Spedlight must be set to baseline manual exposure and output, and manual sync of the camera. It cannot be set to full auto working with, or controlled by the camera and then have the L758D magically read the mind of the camers/flash! The L758D is primarily a measuring tool for ambient/artificial light and a mix of that, and for this it works very, very well. If the lighting mix changes each time, profiling will give very inaccurate results. This is the same for digital as it is for film.

There is insufficient information in your text as to what settings you have proceeded with to arrive at the spurious 5.8 stop.

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Thank you for your reply i just needed someone who had experience with the 758, and it sounds like you have worked with the 758 for years.. I have only had the 758 for a short time, so I needed to practice with it, i was initially shocked at the speedlight results hence me joining this group and hoping to get some understanding from experienced photographers..... But have to say that even in the Sekonic L-758 manual it does explain how to make camera profiles using the color checker..and data transfer software an this is what i did using ambient light..

It all went a bit pair shaped when i tried making flash measurements....I will try to explain later and give as much detail including readings and step by step process of what i did... Then you or anyone can call me an idiot for not using the 758 correctly.. i can take it on the chin..
As suggested by another member in the group (wiltrw) I will try to find someone who also has a light-meter so i can compare results..Obviously preferably someone who has the L-758..but i think i'm going to struggle finding someone..

Well the L-758DR should certainly NOT give 5.8 stops overexposed... I can't imagine what you might have done unless the sync was off (so the flash didn't detect any light at all)... You can integrate ambient and flash with it, so the shutter speed does matter. Can you explain some of what you did in the tests you tried?

mazz236 said:

Then you or anyone can call me an idiot for not using the 758 correctly.. i can take it on the chin..

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That will not happen. I am not into name-calling!

Everybody has a few stumbles with most Sekonic meters. The flagship L758D is a best seller and really, unbeatable in even tell most challenging situations. You will master it eventually!

The manual is rather vague and does contain errors in the text (corrected to some degree with an addendum, usually slipped into the rear cover). I got the opinion it was written by people not fully fluent in English!

There are many aspects of the L758D that can give rise to unusual results, besides not being aware of the two individual (not shared) metering systems -- peope do tend to think the meter is faulty when they cannot transfer readings from spot to incident! Little things like baseline calibaration ( ISO1+ISO2) an exposure shift, filter factors (ISO2) and what an how you are comparing another object against the meter (suh as colour checkers and grey cards). Even additive/subtractive metering and the way the meter 'weighs' readings have some small bearing.

Did you get your video directly from the Sekonic website?

Yes, gather more opinions from other members with advanced use of this meter, but I suspect profiling isn't something high on the list of "to do" tasks for many people.
Anyway, as with a lot of things photographic, film or digital, the devil is in the detail, and that is the meaty bit that is sought. My own use of my two meters is wholly multispot/averaged metering on transparency film in low light in the andscape. There are a few customisations of functions specific to this (the end result is RA-4 hybrid printing), and how the meter handles e.g. reversing the memory and meter buttons). I have used ambient/strobe balancing, both corded and wireless, only twice. I do avoid getting bogged in technical details because this only acts as an unwanted and annoying distraction to the business of making a photograph! KISS ☺

5.8 stops sounds like the sort of result one might get if one took a flash meter set for reflected light readings and used it to measure the light as an incident meter.
Or vice versa .

MattKing said:

5.8 stops sounds like the sort of result one might get if one took a flash meter set for reflected light readings and used it to measure the light as an incident meter.
Or vice versa .

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Pointing the spotmeter at the flash would hurt!

Hi thanks for being a bit patient with me, i've been working this weekend and I'm even working while i'm doing this e-mail, but i managed to find a bit of time to double check the problem i had with the light meter...

At least you guys gave me some confidence in the light meter, so i started to go back to basics and find out what else could be wrong....

Sorry but I never mentioned before, but my set up was using off camera flash via a Yongnuo controller with Yongnuo wireless triggers, this system is a bit tricky to set up as the speed-light has to be in TTL for the controller to work not (manual). So at the back of the speed-light i couldn't tell what power settings it was supposed to be giving out.
Anyway the controller is set to manual, which I originally thought was working ok..... (wrong)

I can say Before the controller did control the speed light power and zoom etc correctly but now I have checked it, and can confirm the controller basically just triggers the speed-light, and has lost it's control..So it was the Speed-light trigger controller which was messing me around after all..

I originally thought i was changing the settings of the flash when actually it wasn't doing anything apart from triggering, that's where the confusion started from, sorry..The only way at the moment i can change the power of the speed light is manually on the speed-light..

I will continue to practice with using the speed lights and light meter.. And now i can relax and concentrate on the photography, instead of spending time querying the equipment..I guess i need to get some more wireless triggers etc, ones which are more reliable... But in the mean time i'll practice with what i have..

Cheers guys..

So much for the reliability of electronics. No symptoms, just croak.

Bill Burk said:

Pointing the spotmeter at the flash would hurt!

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Given the sensitivity of the spot meter, I am reasonably sure such an action would effectively blind the damn thing!

mazz236 said:

And now i can relax and concentrate on the photography, instead of spending time querying the equipment..

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This!
But really, I am no clearer as to what you are doing from reading your second post, and it is very difficult to make a subjective analysis on the internet -- much better to a truly be there watching what is happening!

mazz236 said:

my set up was using off camera flash via a Yongnuo controller with Yongnuo wireless triggers, this system is a bit tricky to set up as the speed-light has to be in TTL for the controller to work

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If your Yungnuo was in eTTL mode, it first emits a (lower power) preflash for the camera to measure, then the camera sends the eTTL flash a command to emit a predetermined amount of light (to give 'proper exposure') when the shutter actually opens.
In those circumstances the normal flash meter is triggered prematurely by the preflash and it bases its reading on that lower power burst and never sees the main burst of light! That MIGHT account for nearly 6EV of overexposure, if you set your camera to that reading!