The Art and Science of Manual Photography
Why use manual mode? Because it gives you full creative control of your images. For example, if you want to get that perfect moon shot, the camera will expose for the black sky in the background, because there is so much more of it compared to the relatively small size of the moon, that your image will be blown out and the moon will seem like a brilliant white orb in the sky with no surface details whatsoever. Manual mode isnt as daunting as it first seems, after awhile your mind will memorize the perfect settings for each situation (for the moon its 1/80 sec shutter speed at f/6.3 and iso 100) and it will seem like second nature for you– basically your brain will become a much larger, much more powerful camera than the one youre using to actually create the images. There are a few things you need to realize before this can be accomplished:

Basically every time you double the iso you shorten the exposure by half. But you also increase noise levels. ISO 400 should be fine though– its a nice middle ground.

DONT USE AN ND4 FILTER!!! ND isnt the same as GND. ND filters are used to slow down your shutter speed, GND’s are used to preserve DR in contrasty situations. The only time you’d really need to use an ND4 filter is in very bright sunlight– it slows down your exposure speed by a factor of 2 stops– thus turning a 1 second exposure into an 4 second one . One stop = doubling (or 2x) the exposure, so 2 stops = 2^2 = 4x. Thats what the 4 in ND4 means. So, umm, without that ND4 filter, your 10 second exposure would have been about 2.5 seconds! (Easiest way to figure this out is to half your shutter speed twice– for example 10/2 ~ 5/2 ~ 2.5). So the ND changed your shutter speed from 2.5 seconds to 10 seconds.

Now one reason that some photographers do use ND filters is to give flowing water that silky smooth effect (the slower shutter speed combines the droplets to give that effect). But this is normally only needed in BRIGHT sunlight. That 2.5 second shutter speed without the ND4 filter would have been just fine in your case. OR just set the iso to 100 (that iso 400 actually negated the 2 stops off your ND4 filter and added some noise into the image to boot– making the filter useless. Basically, iso 400 with an ND4 filter is the same as iso 100 with NO filter!) Increasing the iso to 400 decreased the shutter speed by 2 stops, while putting on an ND4 increased it by 2 stops– so they canceled each other out. If you hadnt used an ND4 filter at all and had set your iso to 400, you would have had a shutter speed of 2.5 seconds, which is still fine for the effect you want. At iso 100 and without that filter, you would have kept your 10 second shutter speed anyway, which IMO is overkill.

The easiest way to remember all this is to recall that one stop = halving or doubling of a given exposure value (depending on whether its an increase or decrease). Two stops = quarter or four times. Three stops = one eighth or eight times. Its all about powers of 2. 2^1(stop)=2 2^2(stop)=4, 2^3(stop)=8, etc.

Here’s the difference between a GND and a normal ND. While an ND filter darkens the whole image (in your case by 2 stops), a GND only darkens one half of the image. That way, the part of the image that would have been exposed correctly without the GND should be on the “bright side” of the filter and the other part on the “dark side.” (Rotate it like you would a Polarizer.) The GND filter I received a couple weeks ago was a GND0.6, meaning, it filters out about 2 stops of light on the “dark” side (same as your ND4), and none at all on the bright side.

Remember that, in many cases, the best filter is no filter at all. No filter can ever increase the amount of light coming into your camera, all they do is decrease, so use them sparingly and only in very specific situations.

BTW when youre messing with manual settings (I always use full manual mode, even on my so called point and shoot camera, as well as dslr– unless Im trying to create a special effect with one of the scene modes), let the live histogram guide you (I think you need to use Live View for this.) Make sure that the curve doesnt cut off to the right or left and that none of the colors are clipped (that is, none reach the top of the histogram.) The best and simplest way to do this is to just set your aperture to 5.6 and mess around with the shutter speed until you get it to look the right way. Also, try to keep your iso fixed at 200 for best image quality (400 is ok though.) A well-kept secret with these kit lenses is that when you have the aperture number set at less than 5.6, it can make the image soft and dull. Thats why people buy the super expensive lenses– to be able to use aperture values like 2.8, 3.2, 3.5, 4, etc. with no loss in image quality. For landscape shots, you shouldnt be going lower than 5.6 anyway– to get the most amount of the image in focus (the higher the aperture number, the greater the depth of field.) An aperture of 8 or 11 would be even better. BTW, aperture works the same way as shutter speed and iso, except that a doubling or halving is a change in TWO stops. I believe this is because aperture refers to the AREA of the lens being used to create the image (and area is a two dimensional number, as opposed to iso and shutter speed which are single dimensional.) To get a one stop differential in aperture, multiply/divide (depending on whether its one stop less or one stop more of light, respectively) the f-number by the square root of 2, or approximately 1.42. For example, an image at f/11 that requires a shutter speed of 2 seconds, can be taken at f/8 (f/11 divided by 1.42) with a shutter speed of 1 second. And can be taken at f/5.6 with a shutter speed of half a second. (Reason being that decreasing the aperture number decreases depth of field– good for portaits– but increases the amount of light being let in, and so requires a quicker shutter speed, stop for stop.) Conversely, the same image can be taken at f/16 (f/11 multiplied by 1.42) with a shutter speed of 4 seconds or f/22 at 8 seconds. (Larger f-number increases depth of field– good for landscapes– but also decreases the amount of light entering the lens, thus the need for longer shutter speeds, stop for stop.) And an image taken with iso 100 and a shutter speed of 2 seconds is the same exposure as one with an iso of 200 and a shutter speed of 1 second or an iso of 400 and a shutter speed of one half second. All those “in between” apertures like 3.2, 3.5, etc. correspond to 1/3 stops (you get these with shutter speeds too)– if you’ll notice, there’s always two values between every doubling or halving of shutter speed (for example: 1/200, 1/250, 1/320, 1/400) or one stop of aperture (for example: f/4, f/4.5, f/4.8, f/5.6). That’s why theyre considered 1/3 stops. Sometimes, you can even obtain 1/3 stops in ISO (for example: 100, 125, 160, 200– though this is normally only done by the camera in auto iso mode.) This also integrates into exposure compensation and EV, which work the same way, except that they dont give you as much control as simply manually altering the aperture, shutter speed and iso.

PS- if we really want to make things complicated and work with all 3 factors together, an exposure of f/5.6 with a shutter speed of 1/500 second and iso 200 is the same as an exposure of f/8 with a shutter speed of 1/1000 second and iso 800! (aperture subtracts one stop of light, shutter speed subtracts another stop, iso adds two stops = net effect of 0 stops, thus equivalent exposure, although the depth of field and the focused area is larger with the higher f-number aperture plus higher noise at iso 800.) This should show you how the three are all tied in together. In general, you want aperture numbers like f/8 and f/11 or greater for landscape work to give a greater depth of field and focus and lesser aperture numbers for portraits, to retain shallow dof and to accentuate your subject. A more complicated example utilizing 1/3 stops : an image with an f/3.5 (like yours) aperture at 1/800 second shutter speed at iso 200 has the same exposure value as an image at f/8 and 1/1250 second at iso 1600. (In the second case, the f-number is 2.3 stops slower– remember doubling the f-number has a 2 stop effect (for example f/4 and f/8)– plus add 0.3 stop for the difference between f/3.5 and f/4, the shutter speed is 0.7 stops slower– two thirds of a stop is rounded to 0.7– (if it was 1/1600 second (half of 1/800 second) it would have been a full stop), but the iso is 3 stops faster = net stop differential of 0.)

Remember that doubling or halving the iso or shutter speeds results in a one stop difference in exposure; doubling or halving the aperture results in a two stop difference, but also either doubles or halves the depth of field (the former if the f-number went up, the latter if it went down.) Just remember how aperture and iso affect shutter speeds and each other and vice versa (and also keep an eye on noise at higher iso’s) and youre good to go. Use the lowest iso you can get away with, unless youre trying to freeze fast action.

You can do exposure bracketing (or just take a bunch of pics at slightly different settings) and go back and look at the review histogram of each to see which one came out best. Eyeing the LCD before (live view) or after (review) helps out alot as well. Finally, trust your own instincts and your own eyes– you have the talent to figure out what looks best to you and Im sure if you let your innate abilities guide you– you’ll do just fine! Remember that photography is more than just math– its an art!!!