Filters?!

[SCHNOOBS]

Neutral density filters? what is the most cmmon used?
.3
.6
.9

 

[Big Mike]

They are most commonly used when you want to get a longer shutter speed than the light would allow.

For example, if you want to use a long shutter speed to blur running water...but the bright light would mean that anything over 1 second (with smallest aperture) would be over exposed. The solution is to add a neutral density filter, which doesn't affect anything else, it just block some of the light so that you need to use a longer shutter speed.

 

[SCHNOOBS]

I am sorry I worded my question wrong.
out of those nd filters, which is used the most? I would like to purchase the most common either .6 or .9
I hope that clarified things a little\

 

[Big Mike]

ND.3 (exposure adjustment = 1 stop)

ND.45 (exposure adjustment = 1.5 stops)

ND.6 (exposure adjustment = 2 stops)

ND.75 (exposure adjustment = 2.5 stops)

ND.9 (exposure adjustment = 3 stops)

I'm not sure there is a 'most common'

 

[SCHNOOBS]

ok cool thanks, i just read that it is best to have an nd filter that does no less than 2 stops and no more then 4 stops, otherwise "their not going to do much"

Thanks again!

 

[JerryPH]

For digital or film? In the digital world its near useless. You lower ISO, raise aperture and even on a well lit day you can severely underexpose.

 

[Big Mike]

I'd prefer to use an ND filter...rather than to severely underexpose.

But for that amount of times that I actually used an ND filter...it may not be worth it it buy one (or two).

 

[sabbath999]

I have one, and it is a 4 stop filter.

Handy for waterfalls, but that's all I use it for.

 

[Big Mike]

For this shot, I believe that I used two ND 2 filters and a circular polarizing filter. It vignetted severely (because of the stacked filters) so I had to crop that out. I think the exposure was 20 or 30 seconds.

 

[Alex_B]

For digital or film? In the digital world its near useless. You lower ISO, raise aperture and even on a well lit day you can severely underexpose.

totally disagree ... NDs are very useful.

What you say can be done with film cameras as well, so it is not even digital-specific.

aperture is something I define in order to achieve a certain DOF ,and lowering ISO has its limits as well as shortening exposures.

- NDs are used to have wide apertures in very bright light (and get correctly exposed images, no one wants underexposure )

- NDs are used to have very long exposures in very bright lights (see the waterfall example)

- NDs are used to get a correct exposure of extremely bright light sources such as in welding, certain melts, and so on.


There is no most common one. It always depends on what you shoot. You should never buy equipment by the needs of others, but by your own needs.

If you are not sure what your needs are, then you apparently have no need for NDs yet

 

[Milhouse]

If you have limited finances for your gear like most of us, I'm not sure if a 2 stop ND is worth it. If your objective is to reduce light by 2 stops, couldn't you do that with a CPL. I think they reduce light by 1-2 stops. Use a CPL when you would need a 2 stop difference, and get a 4 stop ND. You will probably find the CPL more useful in your bag than the ND.

You have to be aware that when the CPL you will also be reducing reflections/glare, so if that is what you were trying to capture then this is not a solution.

I also read somewhere that if you stack 2 CPL that it would act as a ND with infinite stops (as you rotate each one). Not sure what the quality would be like but sounds cool to try.

 

[Alpha]

You lower ISO

Today's digital cameras are losing stops like they're going out of style with every new release. This isn't always an option.

Also, aperture adjustments should be used for aesthetic purposes, or for hitting your lens' sweet spot. You don't want to shoot at an unintended aperture if you don't have to.

 

[Alpha]

If you have limited finances for your gear like most of us, I'm not sure if a 2 stop ND is worth it.

Good CPL's tend to be more expensive than good ND's.

 

[Helen B]

...

I also read somewhere that if you stack 2 CPL that it would act as a ND with infinite stops (as you rotate each one). Not sure what the quality would be like but sounds cool to try.

It's best to use either a linear and then a circular, or a reversed circular then a forwards circular. A circular consists of a linear followed by a depolariser (in simple terms) so a circular followed by a circular will have less density when crossed than a linear followed by a circular. A reversed circular followed by a forwards circular will have little polarising effect on skies and reflections, and behave more like a simple variable density filter.

In general, with good quality polarisers, about eight stops is the maximum that can be achieved when crossed. Polarising and 'depolarising' (delay plate) material is difficult to make with perfect spectral performance, so there may be a noticeable colour cast with crossed or partially crossed polarisers - this may be fully correctable in post. It is, however, a lot easier to make spectrally-neutral ND filters.

Best,
Helen

 

[confucious]

Totally off topic but...

Big Mike - beautiful photo - I love the red (mauve/pink/plum) "sand" rock contrasted with the smooth flowing water.