Is Sekonic 358 calibration needed straight out of the box?

[ChillOne]

So, straight out of the box, any need to calibrate my Sekonic 358 meter to my Nikon dSLR? Or, can I assume the Sekonic QA team calibrated the unit correctly during manufaturing?

 

[Barrie Davis]

So, straight out of the box, any need to calibrate my Sekonic 358 meter to my Nikon dSLR? Or, can I assume the Sekonic QA team calibrated the unit correctly during manufacturing?

Unless something has changed, and meters are now made to much lower standards of consistency than previously, the unit is very unlikely to need calibration straight out of the box.

The calibration may drift a little over a period of years. My Minolta V model is over 10 years old, but has not yet needed any correction from me.

Re-alignment, if ever it becomes necessary, is usually never more than 1/3 stop correction.

Why do you ask? Have you got a meter that seems to be inaccurate? Or are you simply getting information in advance of purchase?
--
Regards,
Baz

"Ahh... But the thing is, they were not just ORDINARY time travellers!"

 

[ChillOne]

Just curious actually. I have not used it yet, but before I did, I needed to know if I needed to update

 

[One Pixel]

So, straight out of the box, any need to calibrate my Sekonic 358 meter to my Nikon dSLR? Or, can I assume the Sekonic QA team calibrated the unit correctly during manufaturing?

Like many people, I thought that the light meter out of the box would be calibrated. Was I wrong. I calibrated the Sekonic 358 to my camera. After the calibration, the meter readings have been accurate (of course this will depend on how you use the meter). I had to re-calibrate the meter for the strobe that I started to use now.

--
Ed W

 

[Barrie Davis]

So, straight out of the box, any need to calibrate my Sekonic 358 meter to my Nikon dSLR? Or, can I assume the Sekonic QA team calibrated the unit correctly during manufacture?

Like many people, I thought that the light meter out of the box would be calibrated. Was I wrong. I calibrated the Sekonic 358 to my camera.

Of course, it could've been the camera that was off... in fact, that is more likely than the meter. Either way, you are correct in that the meter is the item adjusted to attain the match.

After the calibration, the meter readings have been accurate (of course this will depend on how you use the meter).

Well, if you are not taking readings correctly , of course, you will get errors leading to incorrect exposures. Could this have been why you thought the meter was innacurate?

• In the case of reflected readings it is matter of choosing a suitable target tone to read... ideally that will be an 18% grey tone, although other tones can be used as long as you compensate.

• In the case of incident readings it is down to orientating the dome correctly to the light source ... (don't aim at the light, aim at the lens.... or in the case of metering at the edge of the subject field, aim parrallel to the lens' axis.)

I had to re-calibrate the meter for the strobe that I started to use now.

What? That is a RE-calibration of your "out of the box" calibration?

Hmmm.... I am a little concerned that you have had so much trouble matching your meter's recommendations to the sort of exposures you expect to get, and feel your methods of use may be contributing to those problems.
--
Regards,
Baz

"Ahh... But the thing is, they were not just ORDINARY time travellers!"

 

[One Pixel]

I don't think that I'm the only one that had issues with the 358's readings. If you Google it, there are threads about it. I just read one back from 2003 (link below), where that person's 358 readings was overexposing the shot. My shots were also being overexposed per the 358 readings on ambient light.

http://www.prophotohome.com/forum/lighting-equipment-technique/7023-sekonic-l-358-calibration.html

You can easily test the accuracy of the 358's meter reading by bracketing your shots & checking the histogram of those shots. Which shot looks properly exposed? I never had any issues on the meter readings coming from my cameras. I tested the 358's reading on strobe lighting by bracketing the shots with the camera mounted on a tripod. All is happy after adjusting the 358.

--
Ed W

 

[Sailor Blue]

I got my Sekonic L-358 just over a month ago. Fortunately reading from it match my camera & lens, but I didn't trust the meter until I tested it. I mainly work with studio strobes so I checked it to be sure it was working correctly with my camera and all lenses with my studio strobes.

It is important to test your meter against all cameras and all lenses since each of those may vary in how they work and how accurate the camera metering is.

There are two ways of testing a meter that I used. The first is to use a 90% white card. Here is how I did that.

Set up the card on a stand so that it is 6' to 10' from the camera. at lens height, and flat on to the camera. Set up two studio strobes with diffusers at the 45º angles left & right of the white card, centered at card height, and aimed at the card.

Meter each light with your L-358 at your sync speed to make sure that they are at the same power level, and together so that the total exposure is one that you can set on your camera (i.e. f/4, f/5.6/, f/6.3, etc.). Find the aperture at which your camera's Highlight Alert just starts to blink on the body of the card - not the edges which can become bent and reflect light in strange ways. Back off 1/3 stop and you should be reading the same as your meter ±0.1 stop.

If you do a lot of studio work on people then use the FaceMask Histogram. Here is the link to the Will Crockett smArticle on ShootSmarter.com. Registration is free.

http://www.shootsmarter.com/index.php?option=com_content&task=view&id=116&acat=16

Here is a bit of additional information on how to do a FaceMask Histogram. If the subject's face is turned at an angle the Elliptical marquee Tool won't fit properly. Go to Select/Transform Selection and rotate, expand, or contract the selected area to fit properly then hit Enter. Next hit Ctrl-L to see the histogram.

 

[Barrie Davis]

I don't think that I'm the only one that had issues with the 358's readings. If you Google it, there are threads about it. I just read one back from 2003 (link below), where that person's 358 readings was overexposing the shot. My shots were also being overexposed per the 358 readings on ambient light.

Well, if the Sekonic 358 is a less than reliable meter, then I stand corrected. Thank you for putting me right. However, this is all news to me, especially in light of how often the Sekonic meters are strongly recommended. In fact, my assumptions were that Sekonic had inherited the same kind of production standards as Minolta meters, of which I had used several across the years, all of which had been exceedingly accurate and reliable. Besides this, I know several people with Sekonic meters, and they have never mentioned any difficulties... (shrugs)

http://www.prophotohome.com/forum/lighting-equipment-technique/7023-sekonic-l-358-calibration.html

You can easily test the accuracy of the 358's meter reading by bracketing your shots & checking the histogram of those shots. Which shot looks properly exposed? I never had any issues on the meter readings coming from my cameras. I tested the 358's reading on strobe lighting by bracketing the shots with the camera mounted on a tripod. All is happy after adjusting the 358.

I am still puzzled about this re-calibration you did for the strobes. Surely, making changes to the calibration in order to get the flash readings correct would have altered the previously "correct" calibration for ambient light, presumably arrived at by histogram comparison mentioned above?
--
Regards,
Baz

"Ahh... But the thing is, they were not just ORDINARY time travellers!"

 

[One Pixel]

I think that most of the Sekonic meters out there works great out of the box. Unfortunately, some of them don't but it doesn't mean that the ones in this group are not within factory spec. It's basically the luck of the draw with anything being mass produced.

I was surprised that my adjusted 358's flash readings was off when I tested it with the strobe. I zeroed out the adjustments on the 358. Took a flash reading & bracketed the shots. The shot done per the meter reading was underexposed. This was totally opposite of the ambient light readings where they were being overexposed. I probably should send the meter back to Sekonic for an inspection. I has this meter for a few years now. As for light/flash meters out there in the market, there isn't a lot of choices out there.

--
Ed W

 

[Peter Berressem]

Why not check the meter by using the sunny f/16 rule on "open sun" ?
http://en.m.wikipedia.org/wiki/Sunny_16_rule
--
cheers, Peter
Germany

 

[One Pixel]

Why not check the meter by using the sunny f/16 rule on "open sun" ?
http://en.m.wikipedia.org/wiki/Sunny_16_rule
--
cheers, Peter
Germany

Why didn't I think about doing that test. It was a little past noonish when I tried it out here in sunny CA. I zeroed out the adjustment on the 358. Meter settings: ISO 100, TV 100. Held the meter (dome extended) perpendicular to the ground at arms length & took four readings:

North f14
West f14
South f11
East f11

The meter didn't get f16 on a sunny day like today. I guess that this kind of proves that this particular unadjusted meter is giving out overexposed readings on ambient light which confirmed my bracketed test shots.

Thanks Peter.
--
Ed W

 

[Barrie Davis]

I think that most of the Sekonic meters out there works great out of the box. Unfortunately, some of them don't but it doesn't mean that the ones in this group are not within factory spec. It's basically the luck of the draw with anything being mass produced.

To meet previously accepted international standards of consistency, any meter should be accurate within 1/3 stop over most of its range. Even old style analogue selenium meters achieved this, and have done so since the 1930s (Weston Master series). It happens that 1/3 f-stop is about the smallest error that would be consistently identifiable by eye AS an error... and since it is eyes we use to evaluate pictures, this degree of exposure accuracy is quite OK.

However, modern electronic meters should achieve accuracy within 1/10 stop without difficulty, and I'm prepared to assume this is the aim when Sekonic meters are packed up and shipped.

I was surprised that my adjusted 358's flash readings was off when I tested it with the strobe. I zeroed out the adjustments on the 358. Took a flash reading & bracketed the shots. The shot done per the meter reading was underexposed. This was totally opposite of the ambient light readings where they were being overexposed. I probably should send the meter back to Sekonic for an inspection. I has this meter for a few years now. As for light/flash meters out there in the market, there isn't a lot of choices out there.

So your meter currently has different sensitivity to flash light compared with continuous...[??] Well, that is a pretty good indication there is something wrong with it. If I were, you I'd get it sorted out.
--
Regards,
Baz

"Ahh... But the thing is, they were not just ORDINARY time travellers!"

 

[Barrie Davis]

Why not check the meter by using the sunny f/16 rule on "open sun" ?
http://en.m.wikipedia.org/wiki/Sunny_16_rule
--
cheers, Peter
Germany

Why didn't I think about doing that test. It was a little past noonish when I tried it out here in sunny CA. I zeroed out the adjustment on the 358. Meter settings: ISO 100, TV 100. Held the meter (dome extended) perpendicular to the ground at arms length & took four readings:

North f14
West f14
South f11
East f11

The meter didn't get f16 on a sunny day like today. I guess that this kind of proves that this particular unadjusted meter is giving out overexposed readings on ambient light which confirmed my bracketed test shots.

Your Sunny 16 check reading should be taken in the direction of the sun, with the meter held vertically. The reading should be within 1/3 stop of f/16 for at least 4 hours either side of noon at this time of year, in the northern hemisphere.

Your reading of f/14 qualifies as within 1/3 stop, (just!) but one would expect a modern meter to be closer than that.... (f/14 + 4/10ths, say) However, if the sun was directly overhead at (local noon in Southern California, say)...

.... then the light would be striking the dome quite obliquely from above ... (see below)... so the f/14 reading may be entirely correct.

Either way, the points of the compass are not really relevant to these readings, however, the angle of the dome's axis to the light source, [sun] most definitely is.

With the meter held vertically....

• .. at 45° to the sun the reading should be about 1/4 to 1/3 stop lower than directly at sun.

• .. at 90° (side-lighting) reading should be 1/2 stop lower than sun-wards.

• .. with 3/4 backlit, (say 130°) reading will read 2/3 stops lower.

• .. and one FULL stop lower for subjects lit from behind.

It is no accident that the dome shape is chosen for the incident light sensor. The hemisphere automatically applies the above exposure increase factors for light that isn't coming from directly over the top of the camera. What's more, it can integrate multiple light sources from multiple angles all into a single reading, with each light incorporated in proportion to its brightness AND angle of incidence on the subject.

This is why it is important to meter towards the camera lens ,...

.... (or parallel with the lens axis for those readings taken at the edge of the subject field.)
--
Regards,
Baz

"Ahh... But the thing is, they were not just ORDINARY time travellers!"

 

[photolando]

Even Sekonic will tell you you might need to calibrate your meter. There are way too many variables out there. Things like shutter speeds, apertures, lenses, etc. ALL need tweaking over time. Things like camera make are also a varibale. My Canon 40D with my 24-70L does not expose the same as my friends Nikon D200 AND the cheaper lens he has on it.

But I will let Sekonic explain it:

http://www.sekonic.com/Support/FAQs/Calibrating-your-flash-meter.aspx

--
Mike Collins
http://www.prophotoadvice.com

 

[f8BeThereToo]

Every new meter should be calibrated right out of the box; I've seen pro-level gear with meters off by as much as two stops.

The last time that I checked industry standards allowed an exposure variance of up to + or - one stop, which is a lot of slop!

And in my experience large diffusion domes are more demanding when it comes to how the meter is oriented to the light source; small domes are less particular.

 

[One Pixel]

This has been an educational thread for me on light meters. Thank you Barrie & everyone else for your inputs. Looks like I need to redo my testing. My apology to ChillOne for hijacking his thread.

--
Ed W