Will I lose DoF with ND filters

[MileCreations]

I'm sorry if this is a stupid question, I'm only just coming to grips with stuff to do with lenses.

When I put my ND filter on my DSLR lens depending on the filter will my image essentially go from being say a f1.8 to a f2.8 or something and will that make my DoF less narrow?

I haven't bought one yet so I can't simply just test it... The guy at the store said I would 'lose a few stops'

-Brendan

 

[MileCreations]

For the shot you want you DON'T want your entire DoF to be in focus; you DO want to keep just your immediate subject in focus and the rest of the range blurred out of focus.
To achieve this you need to run down your fStop to a big ol' opening which dumps a ton of light on your CMOS sensor.
Fine.
But now you're going to have blowouts galore.
Fine.
Your camera will likely auto correct with a sky-high shutter speed >150 = SAVING PRIVATE RYAN choppiness.

If you manually set your shutter speed to <100 - BAMMO! - everything goes sunny side of Mercury white.
Not good.
Pop on your "sunglasses" ND or variable ND filter and "Ahhhhh!" the aperture can stay open, the shutter speed can stay low, and the subject's movement won't be jittery-jumpy.

Precisely!

 

[jax_rox]

is a 'variable' strength ND filter a good idea?

It works, sure. There are various fader ND solutions around. I'd rather a set of Schneider or Tiffen ND filters, but if you can only afford/ only need a fader ND, then go ahead.

Yeah, I'm interested in the "is it really worth it" aspect between a $35 Polaroid or a $305 Heliopan?
$35: http://www.adorama.com/PDPLFFDND58.html?gclid=COGawuaQlLQCFYG-zAodaBkAxQ
$305: http://www.adorama.com/HP58VND.html?gclid=CLeXrKCRlLQCFY-6zAodPnwAhA

[/quote]

It's debateable, sure. I personally tend to work with Tiffen and Schneider square filters. I prefer Schneider, but Tiffen make decent filters as well.

For example:
http://www.abelcine.com/store/Schneider-4x5.65-True-Pol-Linear-Filter/

Is it a better filter than a $20 polariser off eBay, or even a Polaroid brand? Of course it is. Do you need a better filter? Well, that's up to you.

If you're using the Canon $100 50mm lens, you can probably get away with a $20 polariser. If you're shooting on $4,000 Compact Primes, I wouldn't be using $20 filters...

It's kinda similar to the difference between the three Canon 50mm lenses (ie $100 f/1.8, $500 f/1.4, $1200 f/1.2 L)
The f/1.2L is a much better lens than the f/1.8 or the f/1.4, with better and sharper glass, a better build quality etc. But it comes at a price, as with anything, and not everybody needs or wants the sharper and better glass.

ND filters do degrade an image somewhat, sometimes more noticeably. A cheaper filter is going to have a more noticeable effect on image quality than an expensive one.

This is why Roger Deakins mentions in his IBC talk about the Alexa, the idea of shooting 'clean' and how it's sometimes impossible with the Alexa's native 800 ISO to shoot with max dynamic range by sticking at ISO 800, and shoot 'clean' (without filters). It's perhaps much more pertinent, however, with his work because he's using $30,000 lenses - and then it becomes much more of an argument of 'why put a $600 filter in front of a $30,000 lens?'

As long as you accept and understand the consequence of buying cheaper filters, then you can do what you want. That doesn't mean you have to buy expensive ones, not everyone's shooting stuff that's going to end up on a cinema screen for example.

Just don't complain when you stick in a cheap ND 0.9 so you can get wide open on your $100 50mm lens, and wonder why the image is so damn soft

 

[rayw]

LOL!
Perfect!

Yep, yep, yep. Just what I was hoping for.
Scale the cost of the filter to the value of the lens behind it.
Works for me.

Yeah, I know I need to get one at some point, and I was pretty sure that the Polaroid probably wasn't a total POS, but that the filters would have some diffractive artifact in the less-than-pristine material it was made of.

Cool.

Middle of the road is fine for me. TY!

 

[MileCreations]

As long as you accept and understand the consequence of buying cheaper filters, then you can do what you want. That doesn't mean you have to buy expensive ones, not everyone's shooting stuff that's going to end up on a cinema screen for example.

Just don't complain when you stick in a cheap ND 0.9 so you can get wide open on your $100 50mm lens, and wonder why the image is so damn soft

So how exactly do I know if an ND filter will be good or not? It's not like there's thousands of blogs or videos reviewing them like there are for lenses and cameras?

A lot of places don't have their ND filters online, only in store, from what I've seen

 

[jax_rox]

So how exactly do I know if an ND filter will be good or not? It's not like there's thousands of blogs or videos reviewing them like there are for lenses and cameras?

A lot of places don't have their ND filters online, only in store, from what I've seen

Any ND filter will act as an ND filter, so it's not like you'll buy one and end up with a complete dud. Generally, quality is related to price. Brands I trust are Tiffen and Schneider, but that's not to say that others don't make decent products.

Do what research you can, and make as educated a decision as possible; if you can rent one, give it a go - there are places that will rent you screw-on NDs for $5/day. Generally, if a somewhat reputable rental company is renting them out, then it's not a horrible filter You can also call up rental houses to get an idea of what they think of them - they spend a lot of time prepping their filters, and hear first hand when they come back how they performed, so they'll be able to tell you if a certain filter they rent if worth the money or not. Just make sure they're not run off their feet when you call asking to chat.

 

[MileCreations]

Any ND filter will act as an ND filter, so it's not like you'll buy one and end up with a complete dud. Generally, quality is related to price. Brands I trust are Tiffen and Schneider, but that's not to say that others don't make decent products.

Do what research you can, and make as educated a decision as possible; if you can rent one, give it a go - there are places that will rent you screw-on NDs for $5/day. Generally, if a somewhat reputable rental company is renting them out, then it's not a horrible filter You can also call up rental houses to get an idea of what they think of them - they spend a lot of time prepping their filters, and hear first hand when they come back how they performed, so they'll be able to tell you if a certain filter they rent if worth the money or not. Just make sure they're not run off their feet when you call asking to chat.

Unfortunately I don't know if any rental places in Bendigo, but I'll see what I can find out. The one the guy was showing me, which was a multiple stops one was about a $120 AUD I think he quoted me, I don't remember the brand though

 

[jax_rox]

Unfortunately I don't know if any rental places in Bendigo, but I'll see what I can find out. The one the guy was showing me, which was a multiple stops one was about a $120 AUD I think he quoted me, I don't remember the brand though

Some Melbourne-based rental houses will ship out to you, otherwise a phone call is better than nothing

At the end of the day, the difference between a $30 and $50 filter isn't going to be anywhere near the difference between a $30 and a $300 filter.

 

[MileCreations]

Some Melbourne-based rental houses will ship out to you, otherwise a phone call is better than nothing

At the end of the day, the difference between a $30 and $50 filter isn't going to be anywhere near the difference between a $30 and a $300 filter.

Considering its on a 600D (currently) there are issues at hand with obtaining the best possible image, right?

 

[jax_rox]

Considering its on a 600D (currently) there are issues at hand with obtaining the best possible image, right?

Well, there comes a point where the compression in the video negates the difference in glass. Certainly there's a difference between a $100 50mm f/1.8 Canon lens and a Zeiss 50mm Compact Prime. If you can pick it, you're probably going to pick the difference between a $30 filter and a $500 filter, and also the difference between not having a filter in front of the lens, and having one. If you can't, you probably won't. I can tell you that the prosumer handycams don't use ridiculously expensive glass for their in-camera filtering.

There comes a point where difference in glass is negligible on a DSLR. Sure, on a RED or Alexa or 35mm you're going to really pick the difference between a Compact Prime and a Master Prime or a Cooke s5. On a 600D, you're probably going to struggle to pick the difference between Canon L primes and Zeiss Distagons unless you're really taking notice of sharpness and how they resolve.

The same basic principle applies to filter glass. You also have to ask yourself 'where are my projects going to be shown'? If you're blowing them up for cinema exhibition, you want the best quality out of camera as you possibly can. If they're going to end up on a website or YouTube, then it probably doesn't matter as much - when a screen size is small enough that an out of focus image can look in focus, then the difference in glass is going to be completely unnoticeable.

 

[Ernest Worthing]

Yup. Cost of lens and filter should be taken into account as well. People ask me about UV filters all the time and whether they need them or not and how it protects your lens. My reply is the same. It's kind of not worth it to get a $35 UV filter to protect a $100 lens. That's 35% insurance. It is worth it to protect your $500 lens.

 

[Jack Lynt]

https://www.youtube.com/watch?v=byXjjT74zSI

What do you think of this product? Looking at the prices on B&H, they don't seem too crazy.

Looks like that kit costs 88 USD. A 58mm lens adaptor, for example, costs 32 USD. Don't know what that would run you guys in Australia.

What do you think of Lee filters, Jax, if you've had any experience with them? Though I'm hoping it's no problem to mix and match filters across different brands of filter holders. ?

 

[stef]

Lee makes good filters in general. This looks like a pretty cheap version kit, but that holder looks fine. It's also a graduated ND, which means it's dark on one edge and changes to clear (soft changes over a larger distance, hard changes over a short distance), so that you can place it across the sky to prevent it blowing out without affecting the ground.

Lee makes different quality versions. The plastic ones are cheap, and undoubtedly scratch easily. I believe these filters will also fit into a matte box if they're 4x4. They also make some very expensive filters. I had looked into getting a bigstopper, which allows you to take landscapes of busy areas without any people in it, as long as they move around. You can spend a lot of money on filters, and the good ones aren't very cheap.

Cokin makes some cheap-ass filters, but they might be discontinuing last I read.

Still, if they're cheap plastic but scratch free they should be reasonable for indie film work.

 

[jax_rox]

What an intriguing product.

99% of the time, I use and work with Tiffen and Schneider filters. I've recently seen some Formatt ND's on set, but most rental houses stock Tiffen and Schneider filters.

I use exclusively Lee colour gels - nothing against Rosco, but I simply don't use Rosco gels. So, I can't really give much advice on Lee filters as I've never used them. I know they have the Big Stopper that cuts 10 stops of light that I'd love to use once just to have used it... (shoot in the snow wide-open maybe..?)

That said, all filters I've ever worked with are glass filters. I skipped through the video, but noticed he was using some intriguing plastic filter, so I don't know how that would perform, I can only assume it would be inferior to it's glass alternative.

 

[stef]

I know they have the Big Stopper that cuts 10 stops of light that I'd love to use once just to have used it... (shoot in the snow wide-open maybe..?)

Hah! Unlikely... at 10 stops, if you were shooting at 1/2000, you'd be shooting at 1/2 a second!

I've been wanting to use one to shoot some busy, popular place like Picadilly or NYC in the middle of the day, but without any people. A 3 min exposure at f/16 would remove almost every moving object.

It would just be eerie to see a busy place with empty streets in daylight.

 

[Jack Lynt]

Nice. What do you currently use, Stef?

Mmmm, definitely sounds like glass is what a person wants, Jax. Not at all wanting to you ask you to do any work or put yourself out, and maybe you've already done this, but if you happen to have, or if you ever come by a photo of the typical rig that you work with, please think about posting it...just because it would be cool to see.

=)

 

[stef]

I just use a vari-ND, which is good from about 2-9 stops. It's basically a pair of glass polarizers that rotates to change the amount it blocks.

I think I could use it for 1 stop or less, but I hear it can cause a subtle X across the image due to moire. For 1 stop, I just use my polarizer.

 

[jax_rox]

Hah! Unlikely... at 10 stops, if you were shooting at 1/2000, you'd be shooting at 1/2 a second!

I've been wanting to use one to shoot some busy, popular place like Picadilly or NYC in the middle of the day, but without any people. A 3 min exposure at f/16 would remove almost every moving object.

It would just be eerie to see a busy place with empty streets in daylight.

A 10 stop filter would let you shoot something metering at f/45 at f/1.4!

Nice. What do you currently use, Stef?

Mmmm, definitely sounds like glass is what a person wants, Jax. Not at all wanting to you ask you to do any work or put yourself out, and maybe you've already done this, but if you happen to have, or if you ever come by a photo of the typical rig that you work with, please think about posting it...just because it would be cool to see.

=)

I certainly can, I'm not sure what the appropriate place is, otherwise I'd probably post similar things more often!

 

[Jack Lynt]

I certainly can, I'm not sure what the appropriate place is, otherwise I'd probably post similar things more often!

Awesome. Yeah, I don't know either. Where should it go? Let's try this.