Light Meter help for DSLR

S

shortnstout

Well-known member
Hi,
I just picked up a Sekonic L-758Cine and am trying to figure out how to use it with a DSLR. I know how to use the Spectra ones with a film camera, and can figure out how to use this 758Cine with a film camera (the f/s mode). But I'm not sure how to set it with my DSLR, which uses shutter speed. If set to f/s-mode 50 the meter reads at F3.2, and if I then jog down to T-mode 50 it reads at f/4.5. I believe the T-mode is the more accurate reading. Would the f/s mode only be for a film camera? Was just a bit confused because in the manual it describes f/s as the cinematography mode, and even though DSLRs are digital, they feel like cinematography :love4:
Thanks!
 
After doing more tests, I'd say I'm less certain the T-mode is more accurate than the f/s mode. it may be the other way. haha!
 
Probably they are both right. I would think that f/s mode assumes 180deg shutter so 50fps is 1/100th shutter, whereas T-mode is shutter mode and 50 means 1/50th shutter. f3.2 is one stop faster than f4.5 to account for the one stop loss by using 1/100th vs 1/50th shutter.
 
Personally I'd stay in f/s mode. That is the mode to be used with frame rate, as it stands for frames per second. It assumes that you are shooting at a shutter angle of 180 degrees. If you need to change that, just press the mode button along with the ISO2 button and use the jog wheel to adjust as needed.

Here is a handy little cheat sheet for adjusting angles to fractions:
http://provideocoalition.com/index.php/freshdv/story/shutter_speed_vs_shutter_angle/
 
Thanks! Any tips for figuring out I should adjust the shutter angle to? I guess I could judge with my own eye whether or not it is over/under but was hoping there was a standard for the workflow with the DSLRs. Since the Canon is essentially recording the live view, it seemed like it would be most realistic to go with the Shutter priority at 50. I wasn't sure if the f/s would have to be accounting for any shutter angle equivalent. Should I just change the shutter angle to make the exposure for f/s of 50 match the shutter priority reading? I suppose I could just do exposure compensation also.
 
Just keep it in f/s mode and set the frame rate on the meter to the same frame rate that you are using on the canon (24 or 30). The camera's shutter angle is up to you and the needs of the shot. Traditional shutter speeds in motion pictures / film is 180 degrees, or 1/48. (1/50 is usually the only option given in most cameras and is close enough to 1/48.) f/s is the mode you want to be in- that is the mode for motion pictures / cinematography. By default it is setting the angle at 180 degrees. if you need to change that, follow my directions posted above. If you do that, you do not need to do any exposure compensation / math- as the meter does all the work for you.

Personally, I think you'll just end up getting yourself into trouble if you go with the T-Mode. That mode can work, but it seems counter intuitive to me, and seems like making yourself work harder then you need to IMO ...
 
Hey, not to hijack this thread, but if you happen to see this thread Ryan (or anyone that would have some insight)... I'm looking into getting a light meter. Trying to decide between the Sekonic L-308DC and the L-758Cine. It looks like the biggest difference is the spot meter in the 758. I'm sure it's a nice feature to have, but trying to decide if it's worth the nearly triple price difference from the 308DC.
 
DSLRs don't have shutter angles, so the f/s mode is totally not what you want to use with a DSLR. Use the time mode and manually program in your shutter speed to the light meter.
 
TiE_Shepherd said:
Trying to decide between the Sekonic L-308DC and the L-758Cine
Click to expand...

I bought the L-308DC last month, and it's been a joy to work with. I found the manual very badly written, but once I figured out how to input my settings, this meter has been bang on for exposures.

For spot-meter work I plan on buying a Minolta Spotmeter F from eBay for about $200. ( it's a deadly accurate meter, and I am mostly interested in measuring the exposure range of a shot )
 
TheDingo said:
I bought the L-308DC last month, and it's been a joy to work with. I found the manual very badly written, but once I figured out how to input my settings, this meter has been bang on for exposures.

For spot-meter work I plan on buying a Minolta Spotmeter F from eBay for about $200. ( it's a deadly accurate meter, and I am mostly interested in measuring the exposure range of a shot )
Click to expand...

I've had the Minolta for years. It has a 'memory' mode so you can easily compare areas in terms of stops. After the Wife lost my Honeywell Pentax spot, then the next two were defective, I switched to the Minolta... I don't believe it is made any longer...
 
Barry_Green said:
DSLRs don't have shutter angles, so the f/s mode is totally not what you want to use with a DSLR. Use the time mode and manually program in your shutter speed to the light meter.
Click to expand...

This is what I have been learning with my experimentation. The meter assumes a 180 degree shutter, but the DSLR has no shutter angle, so it is basically like a 360 in a way, right? Meaning that if you wanted to use the f/s mode you could just compensate 1 stop I believe. I've set the meter to -1 stop and this seems to be dead on- so a shutter speed of 50 on my DSLR matches a correct exposure for a f/s of 50 on the Sekonic. There are a few ways to get accurate and easy readings on this meter. You can store different compensations for 3 cameras on the L-758Cine, so I can just stay in the F/S mode for film and video and use this -1 for my Canon and +.7 for my Bolex (because of light loss from it's 130 shutter and the prism). It's easier for me to just know the compensation I need by itself, than trying to do the math in the ISO or shutter angles. I think the way I'm doing it now is fine, but I'm open to suggestions if my logic is off. The T-mode is essentially the same reading as the f/s mode with a -1 compensation, so you could use either. Thanks! One reason to stay in f/s mode is because for some reason they give you more speeds to select from- like f/s 100,120,125,128,150--- whereas it's T 100,125,160.
 
shortnstout said:
The meter assumes a 180 degree shutter, but the DSLR has no shutter angle, so it is basically like a 360 in a way, right?
Click to expand...

180 degree shutter means the exposure is half the frame rate. 24fps? 1/48. 60fps? 1/120. Simple as that.

The rest of your post was just very confusing... However, since DSLRs and most digital cameras don't work with shutter angle (and if you're sucky at math like me calculating on the fly is absurd) just use a mode that lets you input both F-stop (if it says T-stop, it's basically the same thing) and shutter time.
 
TiE_Shepherd said:
Hey, not to hijack this thread, but if you happen to see this thread Ryan (or anyone that would have some insight)... I'm looking into getting a light meter. Trying to decide between the Sekonic L-308DC and the L-758Cine. It looks like the biggest difference is the spot meter in the 758. I'm sure it's a nice feature to have, but trying to decide if it's worth the nearly triple price difference from the 308DC.
Click to expand...

It just depends on your methodology of using you meter. Personally, I find myself using the spot meter 90% of the time, and the incident meter 10%. So, to save cash, I would just get a spot meter. (I do not like having two meters hanging from me, as they get in the way of my working style- so I really like the 758c. It is worth the money, as you'll only have to buy it once.

(Also, just a little inside tip, you can buy the 758c form photostores in Japan for a considerable savings. I got mine (NEW) off ebay for a really good deal about $400. The only catch is that the remote pack for triggering camera flashes will not work with US remote flashes as they have a different protocol. However, I never use flash, so I have never had an issue with that.)
 
Barry_Green said:
DSLRs don't have shutter angles, so the f/s mode is totally not what you want to use with a DSLR. Use the time mode and manually program in your shutter speed to the light meter.
Click to expand...

I have to respectfully disagree here.

Just because DSLR's do not display shutter angle doesn't mean that the f/s mode should not be used. For example, my D7000 allows shutter speeds of 1/30, 1/50, 1/60 ... when I am shooting at 24 fps, I almost always use a shutter angle of 180 degrees, or 1/48. So I set the D7000 to 1/50 and it agrees with my meter- within 1 - 2 tenths anyway. When I shoot in 30 fps, that means a 1/60 which is again 180 degrees. This then allows me to stay in one mode in the meter with out having to flip between modes depending on the camera system I am using - film, digital, whatever. I like to know my meter is setup and ready to go. In the heat of a shoot, I'd rather not have to check yet one more setting on one more device. Also, with the f/s mode there are more options then in the T mode.

This all might just come down to semantics, and personal working preference. But I have found the f/s mode to be very reliable, and the easiest to work with. I change frames rates a whole lot more then I change shutter angle ... to each his own I guess ...
 
A shutter angle in degrees means that the shutter speed varies with the frame rate. DSLRs do not do that. They set a fixed shutter speed, regardless of the frame rate.

If you want to mentally translate f/s into shutter speeds and then set that speed on your DSLR, you are of course free to do so, but it's more mental work. You have to manually set the D7000 to 1/50. If you chose to shoot in 30P, you would have to manually set it to 1/60th. If it has 60P, you'd have to manually set it to 1/120. But that's not the same thing as frames per second 180-degree shutter, because on a film camera you set it in f/s mode and forget about it, and it automatically calculates what the shutter speed will be.
 
Sorry my post was confusing. All I was saying is that the f/s mode is just one stop off from the T mode (shutter priority), so you can get the same reading as the T-mode by compensating -1 on the meter. A shutter of 180 degrees takes half the light (1 stop) from what there would be if there was no shutter. This is how film cameras work. That is why for a bolex (it has a 130 degree shutter), you need to compensate 1/3 stop if you are using a meter that assumes 180 degrees. But if you are using a DSLR, as Barry said, there is no shutter angle (it is, jokingly, like a 360 degree shutter) so you are not losing 1/2 the light (one stop). And this is why there is one stop difference between f/s mode and t-mode; t-mode assumes no shutter angle. It is fine to use T mode as it is, or use the f/s mode and compensate (you don't need to use math because on the L758 you can just dial it in). I prefer f/s mode because I can stay in the same mode and just change the camera profile on the meter for whatever camera I'm using-- plus I get the advantage of the extra speed selections the Sekonic allows in f/s mode. Sorry if that is still confusing, but it makes sense to me. There's just different simple (non-math) ways of doing things on this meter. Thanks for everyone's posts!
 
shortnstout said:
I think the way I'm doing it now is fine, but I'm open to suggestions if my logic is off. The T-mode is essentially the same reading as the f/s mode with a -1 compensation, so you could use either. Thanks! One reason to stay in f/s mode is because for some reason they give you more speeds to select from- like f/s 100,120,125,128,150--- whereas it's T 100,125,160.
Click to expand...

Real movie camera lenses, using T stops, have been calibrated for the light that they transmit. However, most DSLR users do not have such lenses, and the f-stop is sort of 'ballparkish'... hence the need to compensate via some sort of calculation. For my stills, and film, I would typically use an ISO value of 1/2 the manufacturer's rating.

For DSLR's I've tended to use the internal metering more, for the exposure that would be used. However, for setting up, or analyzing a situation, I always use the spot meter. I've tended not to use incident metering, much at all, ever...

For me, given that I've not used continuous artificial lights extensively, getting a meter that reads footcandles directly, thus allowing me to better understand and specify lighitng, given that most 'pro' lights have some form of footcandle(lux) output charts, is a benefit. In that case incident would be fine... (Someone gave me an old Gossen LunaSix that I have yet to get batteries for... the original spec'ed batteries are no longer made...)
 
shortnstout said:
Sorry my post was confusing. All I was saying is that the f/s mode is just one stop off from the T mode (shutter priority), so you can get the same reading as the T-mode by compensating -1 on the meter. A shutter of 180 degrees takes half the light (1 stop) from what there would be if there was no shutter. This is how film cameras work. That is why for a bolex (it has a 130 degree shutter), you need to compensate 1/3 stop if you are using a meter that assumes 180 degrees. But if you are using a DSLR, as Barry said, there is no shutter angle (it is, jokingly, like a 360 degree shutter) so you are not losing 1/2 the light (one stop). And this is why there is one stop difference between f/s mode and t-mode; t-mode assumes no shutter angle. It is fine to use T mode as it is, or use the f/s mode and compensate (you don't need to use math because on the L758 you can just dial it in). I prefer f/s mode because I can stay in the same mode and just change the camera profile on the meter for whatever camera I'm using-- plus I get the advantage of the extra speed selections the Sekonic allows in f/s mode. Sorry if that is still confusing, but it makes sense to me. There's just different simple (non-math) ways of doing things on this meter. Thanks for everyone's posts!
Click to expand...

Exactly ... :)
 
Barry_Green said:
A shutter angle in degrees means that the shutter speed varies with the frame rate. DSLRs do not do that. They set a fixed shutter speed, regardless of the frame rate.
Click to expand...

Yep, understood. But I find myself using shutter speeds of 1/48 (1/50) for 24p, and 1/60 for 30p 99% of the time on DLSR's, as there is not many other options or frame rates for DLSR's- so it all works out for me.

Barry_Green said:
If you want to mentally translate f/s into shutter speeds and then set that speed on your DSLR, you are of course free to do so, but it's more mental work. You have to manually set the D7000 to 1/50. If you chose to shoot in 30P, you would have to manually set it to 1/60th. If it has 60P, you'd have to manually set it to 1/120. But that's not the same thing as frames per second 180-degree shutter, because on a film camera you set it in f/s mode and forget about it, and it automatically calculates what the shutter speed will be.
Click to expand...

I don't find that I have to do any math / translation at all- that is the joy of the meter, and setting up the camera profiles on the 758c. It is all set up to begin with and I don't have to any additional mental work. Yes I do have to set the D7000 to 1/50 manually, or to 1/60 for 30p- but that is not a big deal to me, as checking the camera settings is already a part of my daily routine when staring the day, as I work with so many different cameras that I find myself having to roll through the settings to verify it is setup according to my specifications.

Anyway- I think the key here is to use a methodology that works reliably well for your on set practices. There is no "one way" to correctly meter a scene - it just depends on your style and setup, but there are wrong ways to meter it or interpret the information given. :)
 
I was just playing around with T mode, and I wanted to give those of you a heads up who may be considering using it, that at least on my 758c there isn't an option for 1/50 when in T-mode. I only have 30 and 60. So if I were to use that mode with my DSLR shooting at 24 fps with a 180 degree shutter (1/48) it would not work as I can only select 1/30 or 1/60, which are off enough to cause exposure errors. (If shooting in 30 fps, it is not a big deal, as 1/60 would give me the 180 degree angle.)

Anyway, just one more reason for me to stay in f/s mode, as I do not have to do any math, nor do I have to change modes depending on the camera I'm using. :)
 
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