Measuring Lux levels for different days - help required..!!

Nikonitus

Senior Member
I have lots of troubles getting good results on overcast days which are those one colour full grey/white from wall to wall coverage, no feature or contrasting clouds,, just one shade. It's the kind of day that even with the naked eye, everything, even the brightest colours, look dull and lifeless. My photos also look dull and lifeless on days like this. I'm sure we all no that situation. I call them nightmare days.. Just yesterday I decided to buy a Sekonic L-478D light meter to try and help my settings etc, as it's still winter here and there are lots more nightmare days to come, I'm sure.. This morning I thought (just to pass a bit of time over these cooler days), I would begin to compile a database of days vs conditions vs lux readings. I know it won't be a short term project but I thought it would be the ideal time to get started..

On the L-478, is there a way to measure off lux readings "only"? I see you can add lux info in as an 'additional data' for each reading, but of course it changes each time you vary one of the eternal triangle (Aperture, ISO, Shutter) values, so it's only applicable to that particular reading. I want to meter existing lux only levels, on a daily basis from early morning, to midday, to nightfall, even night time etc in changeable conditions eg, clear blue sunny days, to cloudy/sunny, to overcast, fog and nightmare, to full storm etc,, as many varying conditions as nature can throw at me so I can make that database quite extensive.. I know there are existing sites with similar info but many of them seem very vague, with very rounded off info and even this morning while out there measuring (even with the other 3 settings), I've noticed some very large differences between what I can measure and calculate and what they say. I've skimmed over the L-478D user manual but that doesn't actually cover any "lux only" setting, although I may have missed it. I hate manuals...

Any help is much appreciated...

Nikonitus
 

Nikonitus

Senior Member
You know what, I just went outside again and gave it another shot and yes, I found it was something I was doing and not the device. This time I got constant readings BUT does this still mean that the lux level shown is applicable to that setting only and if I have a dedicated lux meter, it would read differently..??

Nikonitus
 

480sparky

Senior Member
It's basically telling you there's that much light at the moment.

It's subject to change. You can't take a reading at 2:37 PM on a sunny day and expect the same light level 24 hours later, even if it is sunny.

I'm not sure what you're trying to accomplish.
 

Nikonitus

Senior Member
I understand what you're saying, that one moment in time gives one unique reading and even 10 minutes later you may get a different reading, but what I was hoping to get were readings over several days at the same time of day, eg - sunrise, midday, sunset etc, to maybe get a broad range of lux readings to give me an idea of conditions vs lux levels, so I can simply try to calculate some better settings than the ones I may have been using until now, especially in adverse conditions. I know there won't be same readings from day to day or hour to hour for that matter at given times but I was just hoping to get a better understanding of low light levels and where I seem to be making mistakes.. There are also apps for mobile devices out there to help you get some sort of settings for lux levels, but you have to input those levels first. Anyway, thanks for replying... Nikonitus
 

pforsell

Senior Member
I am not quite certain what it is you aim to do, but I'll subscribe to this thread to learn more.

About overcast days and photography... I think the problem is not the amount of light but the quality of the light. In overcast days the whole sky is a huge hemispherical softbox giving almost perfectly flat, directionless and shadowless light, which tends to make many objects seem two-dimensional and lifeless.

You obviously can boost the contrast and saturation and set a desired white balance, but to get some pizzazz into pictures why not experiment with a flashgun or two... perhaps with colored gels?

A ton of interesting reading can be found in David Hobby's Strobist blog: Strobist
 

480sparky

Senior Member
Particulate matter in the air, as well as humidity, can affect how much light reaches the ground. A forest fire or volcanic ash eruption could quickly skew your results.

Changes in latitude also affect the amount of light.

If you are wanting a chart that says, "Hazy overcast, 3PM, Lux=__", I think you're chasing the impossible. If such a scheme actually works, it would have been 'discovered' soon after the advent of photography before there were any meters at all.


What's wrong with the meter in your camera?
 

Dawg Pics

Senior Member
My Dad was an engineer. He did a lot of that type of thing, but instead of trying to track every light condition, he made notes of his camera settings. Of course, with digital, you just have to look at the EXIF data.
You can learn a lot by using a meter. If you do it enough, you will be able to guess better. Good luck.
 
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