# Sekonic L-358 question



## jjd228 (May 2, 2014)

My camera is set to 1/2 stop increments so I can hit 1/180 of a second. When I set the Sekonic L-358 to use 1/2 stop increments the shutter speed matches but the aperture value I get on the meter isn't available for my camera/lens. For example the meter says to use f4.8 but my camera goes from 4.5 to 5.6 when it's on 1/2 stop increments. WTF?


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## beachrat (May 2, 2014)

4.8 is a legit half stop between 4 and 5.6 so the only thing I can think of is that the max aperture on the lens is 4.5.
What lens are you using?


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## jjd228 (May 2, 2014)

beachrat said:


> 4.8 is a legit half stop between 4 and 5.6 so the only thing I can think of is that the max aperture on the lens is 4.5.
> What lens are you using?



Canon EF 50mm f/1.4

Does that help make any sense?


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## beachrat (May 2, 2014)

Wow. Actually makes even less sense with a lens of that quality.
Where the hell is 4.5 coming from?
Gotta think about this a bit.


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## timor (May 2, 2014)

What camera are you using ? 
You can check the settings on L 358 for displaying in half stops only. It looks like DIP switch is set to display 1/3 values.
http://www.sekonic.com/downloads/l-358_english.pdf


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## jjd228 (May 2, 2014)

timor said:


> What camera are you using ?
> You can check the settings on L 358 for displaying in half stops only. It looks like DIP switch is set to display 1/3 values.



The meter and camera (Canon 6D) are set to 1/2 stop increments. The shutter speeds on the meter match the shutter speeds on the camera, but the F stops are off.


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## beachrat (May 2, 2014)

If you go to set the aperture,it goes from 4 to 4.5 to 5.6?


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## timor (May 2, 2014)

beachrat said:


> Wow. Actually makes even less sense with a lens of that quality.
> Where the hell is 4.5 coming from?
> Gotta think about this a bit.


4.5 is a half stop between 4 and 5.6 
http://oberphotographytips.files.wordpress.com/2013/04/aperture-table.jpg


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## jjd228 (May 2, 2014)

beachrat said:


> If you go to set the aperture,it goes from 4 to 4.5 to 5.6?



Yes, when the camera is set to 1/2 stop increments. If I set it to 1/3 stop increments then I have 4, 4.5, 5.0, 5.6. But again, I need to use 1/2 stop increments on the camera so I can hit 1/180 on the shutter speed. However when I set the Sekonic to use 1/2 stop increments the f stop is off. If I set a shutter speed of 1/180 on the meter and take a reading, sometimes it tells me to use an f stop that doesn't exist on my camera.


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## timor (May 2, 2014)

jjd228 said:


> timor said:
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> > What camera are you using ?
> ...


 Read the manual I sent you. Switch #3 if not set "on" gives you aperture display in 1/10 of stop.


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## jjd228 (May 2, 2014)

timor said:


> jjd228 said:
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I have off off on off. The meter is set correctly.


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## jjd228 (May 2, 2014)

The lens just won't stop at 4.8 regardless of whether the camera is set to 1/3 or 1/2 stop increments. Is this normal for this lens?


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## timor (May 2, 2014)

http://www.nphotomag.com/files/2012/03/Understanding_aperture_f_stop_chart.jpg
This chart is a bit clearer. Looks like I lived all my life with a wrong conviction, that f4.5 is a half stop. That's possible, half stops are never marked in numbers on the lenses. . Looks like f4.8 is a half stop according to this chart so your display is correct, nothing wrong with it. On the lens it is a click between 4 and 5.6.


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## timor (May 2, 2014)

Nevertheless I will see, what my Pentax is showing me in that place, as my p&s Canon I have with me right now is showing 5 as a half stop.


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## beachrat (May 2, 2014)

timor said:


> beachrat said:
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> > Wow. Actually makes even less sense with a lens of that quality.
> ...



On that chart 4.5 is a half stop AND a 1/3 stop.
It's a floor wax! It's a dessert topping! It's both!!

All my Nikons go to 4.8 on 1/2 stop setting,and 4.5 on 1/3 so I guess I'm lost on this one.


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## jjd228 (May 2, 2014)

beachrat said:


> timor said:
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That chart doesn't match what I'm seeing at all! My camera/lens set to 1/2 stop increments goes like this:

1.4
1.8
2
2.5
2.8
3.5
4.0
4.5
5.6
6.7
8.0
9.5
11.0
13.0
16.0
19.0
22.0


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## timor (May 2, 2014)

beachrat said:


> timor said:
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Yeah... The other one is better.


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## astroNikon (May 2, 2014)

I'm by far not an expert at this, but
&#12539; You can set shutter speeds from 30 minutes to 1/8000 seconds. *After 1/8000 the shutter
speeds of 1/200 and 1/400 can be set*. (page 11)

another solution I read and now use is use ISO 400 and you will get usable shutter / aperture settings.

I may be way off as I'm only a newbie on these light meters
weird little devices.  You wonder "why"


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## jjd228 (May 2, 2014)

I actually just spoke to Canon. This lens simply doesn't stop at 4.8. Just how it's made they said.


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## beachrat (May 2, 2014)

I wish I had my gear in front of me so I could see if the numbers in my head are right.
I don't want to give bad info like that chart I just looked at.


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## beachrat (May 2, 2014)

jjd228 said:


> I actually just spoke to Canon. This lens simply doesn't stop at 4.8. Just how it's made they said.




Well that solves that mystery.


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## jjd228 (May 2, 2014)

beachrat said:


> jjd228 said:
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> > I actually just spoke to Canon. This lens simply doesn't stop at 4.8. Just how it's made they said.
> ...



Yup but thanks for the help. Just happy to know nothing is broken. Now I'll just have to change the shutter speed or iso until the meter gives me an aperture I can actually use


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## WayneF (May 2, 2014)

timor said:


> beachrat said:
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> > Wow. Actually makes even less sense with a lens of that quality.
> ...





I see it says that, but it is incorrect.  Half stop is 4.8.  Third stops are 4.5 and 5.0.

It is easily computed:  f/stop = sqrt(2)^(stop number + fraction)   where stop number is 0 at f/1 (so f/4 is stop number 4).    

The half stop is sqrt(2)^(4+0.5) is 4.7568.

The third stop is sqrt(2)^(4+0.333) is 4.4898.

One can set a meter or camera to half stops, but seems like the lens could be constructed with its own stops in its own way. Does the lens have an aperture ring and detents on it?


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## timor (May 2, 2014)

beachrat said:


> I don't want to give bad info like that chart I just looked at.


Sorry about that.


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## WayneF (May 2, 2014)

beachrat said:


> timor said:
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In defense of sloppy nomenclature though, there are many approximations in the markings.  Nikon does the same thing for shutter speeds 10 second and 20 seconds, which are both half stops and third stops.   Nice round numbers, but half stops will actually measure 11 seconds and 23 seconds.

And AFAIK, all cameras do it for 30 seconds, which literally can only be 32 seconds (in sequence 1, 2, 4, 8, 16, 32 seconds).  It is marked 30 seconds, but it times at 32 seconds.

The camera shutters do know to perform the correct value in every case, but the marked numbers for just for the public.


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## beachrat (May 2, 2014)

WayneF said:


> beachrat said:
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All true,but it would drive me nuts knowing that when I bump my exposure a 1/3 or a 1/2,it reads the same.
I'm an anal retentive obsessive compulsive nut with stuff like that,and I like knowing the formulas to plug the numbers into so it makes sense to me.


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## WayneF (May 2, 2014)

beachrat said:


> All true,but it would drive me nuts knowing that when I bump my exposure a 1/3 or a 1/2,it reads the same.
> I'm an anal retentive obsessive compulsive nut with stuff like that,and I like knowing the formulas to plug the numbers into so it makes sense to me.




It bothered me a little too, but we can't set both 1/3 and 1/2 stop scales.  We can only see the one selected set at a time.  And we really don't care what the markings say... the actual important thing is that each stop be 2x or 1/2 x the previous, and thirds and half should actually be their corresponding divisions.   

For example, shutter speeds run 1/2, 1/4, 1/8, and then switch to 1/15 and 1/30 and 1/60, and then switch to 1/125, 1/250, 1/500 second.   In the early days, I puzzled how that could work, why they were not all 1/2 the next.

And of course, they are, I was being too literal.  Those are just rounded markings.  The actual values used obviously are necessarily the 2, 4, 8, 16, 32, 64, 128, 256, 512 scale.


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## wickie44 (May 6, 2014)

I know this might sound newbie ish but if my light meter gave me an aperture I couldn't use I'd use the nearest would it make that much of a difference?


Sent from my iPhone using Tapatalk


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## WayneF (May 6, 2014)

wickie44 said:


> I know this might sound newbie ish but if my light meter gave me an aperture I couldn't use I'd use the nearest would it make that much of a difference?



Probably not much difference.  Not sure the deal with That lens, but the difference between a half stop and a third stop is only 1/6 stop  (2/6, 3/6, 4/6).


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## beachrat (May 6, 2014)

Yeah the difference in exposure wouldn't be much at all.
And if you're metering strobes,and they're already pretty close,you could just move them in or out a bit to get it exact anyway.
Not that big a deal.


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