I am aware ND2 reduces 50% and lowers by 2 stop, while ND4 by 755 and 3 stops. I am refering to actual application of the ND, say for the below 3 scenario
1) coastline with sunny weather
2) water fall with reflective water
3) desert with bright reflective sand all around
I bought the Hoya ND8 at around $20.
I'll choose ND4 or ND2.
It can help me cut more light. If I take ND2, I can decrease the ISO or aperture to cut light.
That is why I bought for Hoya ND8.
It can help me cut more light even during broad daylight situations and also at night.
There is no one fix filter for every occassions. Sometimes u want to shoot with larger aperture in bright lights, sometimes u need very long exposure for some moving water body.
I dun understand about the "3) desert with bright reflective sand all around " though
Ryan
i think i pay about $30 - $40 for it. it's Marumi DHG light control 8. bought it from japan
I bought the China made ND4, ND8 and gradual ND. Cheap, usable and don't need to crack brain on decision over price.
I read somewhere that cheap ND can pose a threat to your eyes as it gives you a false perception that all spectrum/radiation has been filtered. So if you look directly into bright source for prolong period, you can damage your eyes. Just be careful with how you use it.