That's my main question before buying!Originally Posted by cgbier
So far, when I did the test, I've been fine with 2xND8 + 1xND4 on a bright sunny day. That being said, it's only to use at f/1.8, otherwise I'd close the iris a bit to compensate.
I thought 2x0.6 and 1x1.5 would be good: if it's bright and sunny, I could use the 1.5 + 0.6 and if it's a bit cloudy, go with the 0.6x2. What you'd say?
Difficult to say. What'd be your measured shutter speed without filter? Let's say it is 1/1000, then you have to count down to 1/60 - that's 4 stops --> you'll need one 1.2 filter. (just an example)
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
How do you calculate it?
But, my main question is, as I'll get more than one, what would be the best bet for a "starter" kit? Around 200$.
0.3 is one stop, 0.6 = 2 stops, ...
The calculation is pretty simple: with each stop you halve the light that falls on your sensor. 3 stops will be 100%/8=12.5%, 2 stops (2^2) = 100%/4 = 25%, ..... that's the NDx number
You also can express it as fraction (like on video cameras): 1/2 = 1 stop, 1/4 = 2 stops, 1/8 = 3 stops ...
To get your starter kit, you need to know haw many stops you'll need from the measured exposure down to the one you want achieve. That's your starting point. Let's say it is six stops, then you can get a set of 0.3, 0.6, 0.9 or thereabouts. Break the number of the total difference into parts for when it gets darker - you most likely don't always need your s stops.
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
I'll have to read it again (very poor in Maths) but I've found that chart, which (visually) explains it better (to me!!):
So I guess that if I go with the 1x1.5 and 2x0.6 I would be ok for now? I just want something that could suits "general purposes/situation".
lens area opening, as fraction of the complete lens optical density f-stop reduction % transmittance 1 0.0 100% ND2 1/2 0.3 1 50% ND4 1/4 0.6 2 25% ND8 1/8 0.9 3 12.5% ND16 1/16 1.2 4 6.25% ND32 1/32 1.5 5 3.125% ND64 1/64 1.8 6 1.563% ND128 1/128 2.1 7 0.781% ND256 1/256 2.4 8 0.391% ND512 1/512 2.7 9 0.195% ND1024 1/1024 3.0 10 0.098% ND2048 1/2048 3.3 11 0.049% ND4096 1/4096 3.6 12 0.024% ND8192 1/8192 3.9 13 0.012%
Math is simple!
Take a 0.3 into your equation. Sometime you'll only need that ONE stop.
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
1) Like drawing too, depends for each!Math is simple!
Take a 0.3 into your equation. Sometime you'll only need that ONE stop.
2) I'll probably wait for that 0.3, unless you'd say I'd be better with only one 0.6 (so I'd get 1x1.5 + 1x0.6+ 1x0.3)?
That'd give you more flexibility.
Have you measured your exposure already?
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
1) I would be afraid that one 0.3 wouldn't be as useful as another 0.6...let's see.
2) I'm not much of an expert in that, still learning a lot. How would I do that (except with a light meter)?
Well, you aim your cam at for victim and depress the shutter button halfway. Best is to that in Av mode (set to 1.8 or whatever aperture you want to use). Just note down the shutter speed. One stop means double the speed. The list of full stops goes as follows:
1 - 1/2 - 1/4 - 1/8 - 1/15 - 1/30 - 1/60 - 1/125 - 1/250 - 1/500 - 1/1000 - 1/2000 - 1/4000 (30p/60i)
You just count down the number of stops from your measured value down to your needed 1/60.
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
Only thing is that it's not for the HV. With the HV it would be easier to adjust because I can set either the shutter speed or the f/1.8 and then I can also adjust the exposure.
It'll be for the DSLR mainly, in order to use prime lenses outdoor in bright daylight.
Uhm, any camera that you set to a specific aperture will choose the shutter speed itself in Av, or does a DSLR only work fully manual? That can also be solved: Set your aperture then scroll the shutter wheel until the meter readout in the viewfinder is centered. then count back the stops and use the appropriate ND filters.
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
Uhm, don't get me wrong, but do you have any background knowledge in the theory of exposure?
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
Ok, actually that whole thing is pretty simple: When you set your aperture and shutter (leaving ISO out of the game right now), all you do is setting a specific exposure value (EV) - basically the amount of light you let through the lens. Exposure value is a combination of shutter speed and aperture. You can change them both, but still keep the same EV. You slow down your shutter one stop, you have to open up your aperture by one stop.
Wikipedia has an EV table that once was in every camera manual. Look over this table, and you'll understand exposure.
You understand what shutter speed (motion) and aperture (DOF) are used for?
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
1) after a good 10 seconds look at that table, I think I'm more mixed up! lol
2) Shutter speed is the time allowed for the light to "hit" the sensor. Aperture, Iris on the lens? f/1.8 and all, right? Which determines how much light will enter, and also determines the zone of acceptable sharpness.
Right, but also the shutter speed controls how much light enters the lens. That why shoot with a slow shutter speed in coal mines, and fast ones on a tropical island.
Look at the table for EV15 (sunny day), then check the shutter speed for f/2.0. Next check the f/stop for 1/60 @ EV15. Now count the stops. That'll tell you what ND filter to use. It's really pretty basic.
8000 - 4000 - 2000 - 1000 - 500 - 250 - 125 - 60 --> 7 stop difference --> 2.1 filter. You'll have to order any combination of ND filters that'll add up to 2.1 (or you get one with 2.1 - which I wouldn't recommend).
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
Ok, so from the table you've linked:
EV f-number 1.0 1.4 2.0 2.8 4.0 5.6 8.0 11 16 22 32 45 64 −6 60 2 m 4 m 8 m 16 m 32 m 64 m 128 m 256 m 512 m 1024 m 2048 m 4096 m −5 30 60 2 m 4 m 8 m 16 m 32 m 64 m 128 m 256 m 512 m 1024 m 2048 m −4 15 30 60 2 m 4 m 8 m 16 m 32 m 64 m 128 m 256 m 512 m 1024 m −3 8 15 30 60 2 m 4 m 8 m 16 m 32 m 64 m 128 m 256 m 512 m −2 4 8 15 30 60 2 m 4 m 8 m 16 m 32 m 64 m 128 m 256 m −1 2 4 8 15 30 60 2 m 4 m 8 m 16 m 32 m 64 m 128 m 0 1 2 4 8 15 30 60 2 m 4 m 8 m 16 m 32 m 64 m 1 1/2 1 2 4 8 15 30 60 2 m 4 m 8 m 16 m 32 m 2 1/4 1/2 1 2 4 8 15 30 60 2 m 4 m 8 m 16 m 3 1/8 1/4 1/2 1 2 4 8 15 30 60 2 m 4 m 8 m 4 1/15 1/8 1/4 1/2 1 2 4 8 15 30 60 2 m 4 m 5 1/30 1/15 1/8 1/4 1/2 1 2 4 8 15 30 60 2 m 6 1/60 1/30 1/15 1/8 1/4 1/2 1 2 4 8 15 30 60 7 1/125 1/60 1/30 1/15 1/8 1/4 1/2 1 2 4 8 15 30 8 1/250 1/125 1/60 1/30 1/15 1/8 1/4 1/2 1 2 4 8 15 9 1/500 1/250 1/125 1/60 1/30 1/15 1/8 1/4 1/2 1 2 4 8 10 1/1000 1/500 1/250 1/125 1/60 1/30 1/15 1/8 1/4 1/2 1 2 4 11 1/2000 1/1000 1/500 1/250 1/125 1/60 1/30 1/15 1/8 1/4 1/2 1 2 12 1/4000 1/2000 1/1000 1/500 1/250 1/125 1/60 1/30 1/15 1/8 1/4 1/2 1 13 1/8000 1/4000 1/2000 1/1000 1/500 1/250 1/125 1/60 1/30 1/15 1/8 1/4 1/2 14 1/8000 1/4000 1/2000 1/1000 1/500 1/250 1/125 1/60 1/30 1/15 1/8 1/4 15 1/8000 1/4000 1/2000 1/1000 1/500 1/250 1/125 1/60 1/30 1/15 1/8 16 1/8000 1/4000 1/2000 1/1000 1/500 1/250 1/125 1/60 1/30 1/15 17 1/8000 1/4000 1/2000 1/1000 1/500 1/250 1/125 1/60 1/30 18 1/8000 1/4000 1/2000 1/1000 1/500 1/250 1/125 1/60 19 1/8000 1/4000 1/2000 1/1000 1/500 1/250 1/125 20 1/8000 1/4000 1/2000 1/1000 1/500 1/250 21 1/8000 1/4000 1/2000 1/1000 1/500 EV 1.0 1.4 2.0 2.8 4.0 5.6 8.0 11 16 22 32 45 64 f-number
Let's say I set the lens at f/2.0, I'd like to shoot at 1/60, it gives me 8 as EV. Then I don't get what I'd have to do...sorry!
Edit: the correct f-numbers are in the bottom, top can't be corrected from copy&paste.
No, you go along the rows (from left to right). You base your measurement on the light you have available.
But it's the same difference: 15 - 8 = 7 Stops....
Are we looking at the same table? Mine gives 1/8000 @ f/2.0 with EV15....
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
1) Thanks! Now I got it right!Look at the table for EV15 (sunny day), then check the shutter speed for f/2.0. Next check the f/stop for 1/60 @ EV15. Now count the stops. That'll tell you what ND filter to use. It's really pretty basic.
8000 - 4000 - 2000 - 1000 - 500 - 250 - 125 - 60 --> 7 stop difference --> 2.1 filter. You'll have to order any combination of ND filters that'll add up to 2.1 (or you get one with 2.1 - which I wouldn't recommend).
2) So my initial whishlist with 1.5 & 0.6 was quite good! I think I'll go that route then, maybe add the extra 0.3 as you suggested!
Thanks! Both chart printed and I'll keep them in the case to help to familiarize with that new stuff! Learned something quite big and important tonight!
Well, if you want 1/50 at f1.8 in sunlight, on 100 ISO, then you need about six stops.
An ND 1.5 is only 5 stops, so to get six, you need an ND 1.8.
One stop really means nothing, so I'd leave out the ND 0.3, and get the triple set Drape suggests: 0.6, 0.9 and 1.5
Can say absolutely nothing about quality of Cavision vs. Chinese filters... but I assume the latter probably are of lower quality! (Unless Cavision just re-brands Chinese imports... you never know!)
1) So, for one stop, I could always stop down the lens, 1.8 > 2.0 and it would do mostly the same than adding another filter?
2) All right, I'm more aware of that stuff now. So far I think I'd go with that: 1x1.5 + 2x0.6 for a total of 9 stops. The way I see it: I could use simply the 1.5 alone, combined with a 0.6 or simply 2x0.6 combined depending on the amount of light outside. Then I could always adjust the aperture to add some stops if needed.
Thanks guys, I've learned a lot tonight!
1.8 - 2.0 is only about 1/3 of a stop
It's a logarithmic series: 1.0 - 1.4 - 2.0 - 2.8 - 4.0 - 5.6 - 8 - 11 - 16 - 22 - 32 - 64
"It is dark the other side. Very dark!" - "Oh, shut up and eat your toast!"
Sorry, I meant 2.8 (otherwise it's in-between on my NIKKOR! =P)1.8 - 2.0 is only about 1/3 of a stop
Time to go to bed I think!
Thanks again for the infos CG!
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