Are you using a sturdy tripod, because the shots don't look quite sharp? I assume that these are taken at sunrise or sunset because your white balance is off. There is no metadata with these images to help figure things out.
On the other hand, if this is the effect that you are trying to achieve, great! Don't forget that the reason you are using hte ND is to cut down the amount of light hitting the sensor, something that you can certainly achieve under normal low-light situations.
Thank you Manfred,yes my tripod is not very good,I certainly have to buy a better one.These photos were taken at sunset and in fact I wanted to make the water flatter but I didn't have a nd filter and a remote control device to have a longer shot.First one is f 36,30 sec. and the second one is f 14 ,30 sec.After these shots I decided to buy a 10 stop nd,because I loved long exposures..Now I have a 10 stop nd:-)
With exposures that long; you really have to make sure that your camera does not move. I upgraded my tripod for exactly the same reason. It was good enough for regular shots, but once the expoures ran into more than a few seconds, it was not rigid enough.
Binnur, you already know where I stand on the colouring issue, so I won't repeat that. My opinion on these images is that they don't seem sharp enough. It's understandable if you are going for a soft image for artistic reasons, but it doesn't seem to work for these particular shots. Also, i would shoot lower to ensure a stronger composition.
Hi Binnur, exposures this long for water seem too milky to be realistic to me. I keep expecting that if the water is that smooth, it would also be crystal clear and I should be able to see what is under the surface. It is not wrong, simply different from what I would expect.
If you can, try to use long exposure on water that's moving; the more the better (eg breaking / surging water is ideal). It'll turn into "mist" with a long exposure, eg
Generally, a 10 Stop ND is a PITA to work with; in other situations you can just take multiple shorter exposures are stack them in PP; I think that for this shot I stacked a few dozen of them (it does wonders for the noise level also)
Difficult to work the composition with them, and too inflexible.
If you've ever shot with a Singh-Ray Vari-ND (2 to 8 stops attenuation with a twist of the wrist), you'd sell the 10 stop in a heartbeat.
With a Vari-ND you get both shutterspeed AND aperture control, and can vary the attenuation to recompose easily .. and adjust the attenuation easily as light levels change (as they do rapidly during the golden hour).