lovelylyn Loc: Fort Wayne, IN

I’ve read I need an ND filter outside, especially on a sunny day but not sure what kind or size to get. Is their a place to get that info? Will a lens hood eliminate the need for that?

Anvil Loc: Loveland, CO

You don't NEED a neutral density filter, unless, for some reason, you want a long shutter speed. If, for instance, you want silky water in a waterfall, you might need an ND filter, to slow the shutter speed sufficiently, although you might be surprised what you can achieve without one. What are you trying to achieve that makes you want a long shutter speed? A lens hood will help eliminate lens flares, which is a completely different issue.

Perhaps you are thinking of a graduated ND filter, which is a square filter that is darker towards one end, and clear toward the other. With such a filter you can expose for the darker, non-sky areas without suffering a blown-out sky, but even this is not really a NEED.

spaceylb Loc: Long Beach, N.Y.

A polarizing filter is what you "need". 58mm

CHG_CANON Loc: the Windy City

You might also go with an ND filter to shoot with a wider aperture in bright sunlight. But, just randomly purchasing an ND filter is probably not the way to go. You also need to investigate the strength of the filter as they come from 1-stop to 16-stops blocking power. Assuming the need for bright sunlight, look at 1- and 2-stop strength.

rook2c4 Loc: Philadelphia, PA USA

Or be able to get narrow DOF with large apertures in bright light conditions. That is generally what I use ND filters for, not waterfalls.

Anvil Loc: Loveland, CO

Yes, you are absolutely correct, an ND filter is also useful for allowing a large aperture in the bright sunlight. I usually use them for long exposures, which is, no doubt, why I neglected that use.

CO

The first filter you should get is a circular polarizer. They're great for outdoor photos. They can cut through glare such a shiny leaves on trees and other foliage. That will help to saturate colors a little more. They can also darken blue skies and clouds will be a little better defined against the sky.

Also get a couple of neutral density filters. Avoid the variable ND filters. I just use a 3-stop and a 4-stop ND filter.

jerryc41 Loc: Catskill Mts of NY

"Need" doesn't apply here. The ND is more of a specialty filter to achieve certain effects. Here are some links. (Sorry there are so many. ) I have more if you want them.

http://friedmanarchives.blogspot.com/2018/02/neutral-density-filters-vs.html
https://www.howtogeek.com/325803/how-neutral-density-filters-work-and-how-to-use-them-for-better-photography/
https://improvephotography.com/40253/nd-filters-30-filters-reviewed-compared/
http://www.alexwisephotography.net/blog/2009/07/23/neutral-density-reference-chart/
http://digital-photography-school.com/beginners-guide-buying-filters/
http://digital-photography-school.com/step-by-step-guide-to-long-exposure-photography/
http://www.the-digital-picture.com/Reviews/10-Stop-Neutral-Density-Filter.aspx
http://www.cambridgeincolour.com/tutorials/neutral-density-filters.htm
http://www.alexwisephotography.net/blog/2009/07/23/neutral-density-reference-chart/
https://www.youtube.com/watch?v=ZpNtAXbaNr0
https://www.ephotozine.com/article/how-an-nd-filter-can-remove-crowds-from-busy-shots--27054

cybercord Loc: Ga, USA

The word NEED depends on the application and result your looking for. Several good suggestions above about the CPL filter. Buy a good one, and not the cheap ones. I have that lens and use my ND filters along with the CPL filters to capture a more shallow DOF while also slowing down the shutter speed. I do this for car racing. It is useful when wanting to show movement and shallow DOF in sports and movement photos. So I need them, but only in specific photos. Most of the time, the filter sides in my bag.

amfoto1 Loc: San Jose, Calif. USA

Previous responses are correct...

You don't "need" an Neutral Density filter at all, unless you are looking to do some shots with special effects such as an unusually slow shutter speed causing blur or an unusually large aperture for very shallow depth of field. If wanting to do either or both of those in bright lighting conditions, you then need to figure out how much light reduction is needed and select the right strength ND filter to accomplish it. There are also uses for ND filters when shooting video, if that's what you're doing. But, overall, ND filters are pretty specialized... are only needed for certain, specific purposes.

While I completely agree that Circular Polarizers are the most useful type of filter for digital photography, for the types of shots where I use my 85mm lens a lot, I rarely need or use a C-Pol or any filter. (Note: An 85mm f/1.8 lens "might" use a 58mm diameter filter... some do... some use other sizes. Check what size is used by your lens before ordering any filters for it.)

A lens hood serves a different purpose, and in my opinion is virtually ALWAYS a good idea to use while shooting. A hood keeps oblique light off the front of the lens, helping improve image quality by reducing or preventing flare effects. A hood also physically protects the front element of the lens from bumps or rain drops or whatever. The relatively deep hood a telephoto like an 85mm lens uses is especially good protecting the lens. My advice if you don't already have it is to look up the matched hood for your lens, buy it before spending money on any filters, and then get in the habit of using the hood. Most matched hoods today are designed to reverse on the lens when storing it, so take up minimal space in your camera bag.

You might actually be thinking of a "UV" or "protection" filter for your lens (as opposed to ND). That's a whole different can of worms and you'll get arguments both for and against using those basically clear types of filters. Generally speaking, the filter only serves to protect. UV light filtration is largely unnecessary with digital cameras (OTOH, it was important with film, which is where using that type filter actually got started... not for "protection"). If this is what you are asking about... a "protection" filter... I would simply suggest you view the following video and decide for yourself whether you should spend the money on one: https://www.youtube.com/watch?v=P0CLPTd6Bds (Personally I have UV filters in various sizes for my lenses... but only install them when actually needed. They are among my least used photo accessories.)

Any filters you choose to use for any reason, I recommend only getting very high quality, multi-coated ones... to insure the best possible images while using the filter. Those cost more, of course. But cheap, uncoated filters can potentially spoil every image made with them and are the real waste of money. And there aren't really a lot of filters needed for digital... nowhere near as many different types as we needed for film. Much of the effects of filters can now be accomplished with camera white balance adjustments or in post-processing software. And often that's better than it was ever done with film and filters!