posting in desperation shutter speeds

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john
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Hi as the heading shows i am desperate to find a way that i can understand the shutter speed readings on my canon 5d mk 111.
To cut to the chase as it were i have been shooting for several years now so i am confident with my camera and have no problems with iso f/stops etc or even shutter speed.
My problem is and i know everyone says its very simple.BUT. i am not able to calculate in my head what the shutter speeds display show me and how to convert into what my long exposure app needs to know. I am now wanting to start long exposure shooting 6 stop big stopper etc etc. Before i go on any further i am very very practical person and i wont say why but i cannot calculate or read fractions or maths. I have tried to make up a basic spreadsheet converting canon fractions into what i need to dial in to exposure calculator but not very successfull. I would apreciate any help .But in the nicest possible way i only need to know how i convert them ,nothing else. Regards
 
I know what your talking about, as it confuses me sometimes.
It's more when it gets to the slower speeds, sometimes I think "is that 5 seconds or 1/5 of a second.
 
I used to have a circular slide rule type device that worked out all the various combinations.
Made it from online instructions using supplied print outs, will try and find it again
 
Thanks for replies and this is embarassing for me but just to give a instance i am strugling to understand the fractions on my display.IE 0"5 0"3 "125" 100 8000 1" etc etc theese are just examples but when it comes to dialing them in to corespond to the the correct exposure with whatever stopper i want to use i get confused what speeds lighn up in the exposure app. Sorry i know this is not very clear but maybee canon users will know what i mean. I am told that nickon dont show speeds the same and something like = 1/250 1/500 etc etc now that i can understand .
 
the fractions on my display.IE 0"5 0"3 "125" 100 8000 1"


OK, I'm a Nikon and Fuji user rather than Canon but I'd guess that 0"5 means 0.5 seconds, 0"3 means 0.3 seconds, 100 means 1/100th, 8000 1/8000 and 1" means 1 second.
 
Is it figuring out what the numbers mean? ie is 0'5 half a second or is it working out what the correct exposure should be from 0'5 with say a 6 stopper?
Personally I have never found the "official" figures for my filters spot on, I actually test mine with a light meter and write it on the holder. My 6 stopper is actually 4.5 stops. Even with this I still use the histogram to check each shot when I use filters (which being honest isn't that often).
 
Is it figuring out what the numbers mean? ie is 0'5 half a second or is it working out what the correct exposure should be from 0'5 with say a 6 stopper?
Personally I have never found the "official" figures for my filters spot on, I actually test mine with a light meter and write it on the holder. My 6 stopper is actually 4.5 stops. Even with this I still use the histogram to check each shot when I use filters (which being honest isn't that often).
What the numbers mean.
 
8000 th of a second
4000 th of a second
2000 th of a second
1000 th of a second
500 th of a second
250 th of a second
125 th of a second
60 th of a second
30 th of a second
20 th of a second
10 th of a second
0"5 = 0.5 of a second
0"3 = 0.3 of a second
0"1 = 0.1 of a second
1" = 1 second
3" = 3 seconds
5" = 5 seconds
 
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Some good tips and i think it is now sinking in what i wanted to know. Bobsyerunkcle thanks for the breakdown its a great help.I have also found a free app by quicksoft called Exposure Calculator that looks like it will do what i want. Anything connected with maths or as we used to call them sums and i have a mental blockage. Thanks again guys hopefully ill get this sorted and maybee have something to post on here.
 
I have to admit I sometimes find the numbering slightly confusing. If I'm scrolling down it's fine, I can see the progression, If on the other hand I turn the camera on and it says '5 or whatever I do have to think for a second which is it, half a second or one fifth?
 
The internationally recognised sign for seconds is ". I don't know about other manufacturers but on my Nikons this is used eg:
5" = 5 seconds
If there is no sign after the number, eg 5, it is the reciprocal of the number - in this case 1/5 seconds

BTW I've just checked, and Sony uses the same system
 
Maybe this little trick will work for you.

6 stops is 18 clicks of 1/3rd stops each on the shutter speed dial (assuming you've not changed it from the default). So...

Establish correct exposure without the filter in the normal way, then attach the filter and dial the shutter speed down 18 clicks. So long as this doesn't take the shutter speed longer than 30 seconds (camera's maximum) this method is quick and easy without any mental arithmetic.

As mentioned above, many very dark ND filters are not exactly as marked, so test your copy first. You may need 16 clicks, or 19 etc.
 
To be honest I’ve never done a calculation for long exposure and get on just fine. I’m not keen on maths either and usually inadvertently skip anything showing lots of figures. Trial and error is fine and once you really get used to your filter you’ll instinctively know what shutter speed to try and can adjust as necessary.
 
I have to admit I sometimes find the numbering slightly confusing. If I'm scrolling down it's fine, I can see the progression, If on the other hand I turn the camera on and it says '5 or whatever I do have to think for a second which is it, half a second or one fifth?

As written, it could be 30 seconds... ' represents minutes and " seconds. ;)
 
hoppyUK that is a great tip and i will try next time i am out, I am not looking for perfect exposures at this time,but just to gain confidence in long exposure shooting .
I have done some longish exposures up to 30 sec but after that the problems start when i have to calculate .Thanks everyone.
 
I have various long exposure apps on my phone as they are so much easier than calculating yourself. Lee do an app but I’ve not used it. My favourite is LE calculator ion an iPhone. It displays the large number of the fractions bigger than the 1/ so that may help you. It sounds like “ means seconds on s canon camera (I’ve never used one). Seconds are shown clearly by the word sec.
 
hoppyUK that is a great tip and i will try next time i am out, I am not looking for perfect exposures at this time,but just to gain confidence in long exposure shooting .
I have done some longish exposures up to 30 sec but after that the problems start when i have to calculate .Thanks everyone.

You're welcome John.

Another thing that's worth knowing, which I discovered by accident, is that the frame counter has a couple of other functions (on Canons at least). When the shutter speed dial is on B for long exposures, it counts up in seconds - saves you messing with a watch etc. It also counts down the seconds when the self-timer is on.
 
found this link after hours of searching and glad to say it works really good. I tried it today and it was very easy to use
View: https://www.youtube.com/watch?v=2b6I4RVqUNo

I had to do a couple of test shots first but will experiment further when i get more time. rob-nikon thanks for that ill have a look at it and john as you say on my canon with bulb dialed in it does have a countdown/up timer.All i need now is some good compositions for black and white shots.
 
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