ND filters built in?

[DDahlquist]

Hay Gerald,
When I used to shoot 16-mm we were all using series 9 filters witch can take rough handling because of the metal ring around them. I had a filter pac on my belt and a cool pop in filter holder that allowed we to change filters fast and one handed. I'll see if I still have it if so I will send you pics.

Take care
Dave D

 

[Gerald Menclik]

Hay Gerald,
When I used to shoot 16-mm we were all using series 9 filters witch can take rough handling because of the metal ring around them. I had a filter pac on my belt and a cool pop in filter holder that allowed we to change filters fast and one handed. I'll see if I still have it if so I will send you pics.

Take care
Dave D

Thanks Dave,

starting to transform from ENG to cinematographer ....... :confused1:

all the best
Gerald

 

[Michael Brennan]

It would probably have to be limited to the 2/3" Scarlet because an internal filter wheel would get rather large if it had to rotate in front of, and cover, S35 and FF35. It's also one more thing to get dirty in front of the sensor.

Japanese manufacturers do a good job in making a filter wheel assembly that is dust proof and utilising it is a million percent easier than keeping a set of 4x 5.6 filters clean, especially in a doc situation!

Yes a multi slot filter wheel would be cumbersome for the larger formats but a dual slot vertical sliding filter could be accommodated in a ground up design of a new camera.

When one is trying to maintain shallow depth of field or optimum t stop on the run using 2/3 inch sensors the filter wheel is invaluable, for example if one is flipping a doubler in and out for a quick close-up (sometimes a necessary evil when using a wide zoom lens).

Not to mention the ease of offering an editor a choice of shallow and deep DoF for cutaways.

Wide lenses on 2/3 inch with one front of lens filter has its problems with fringing on the edges of frame and becomes a problem with two filters.
Also without a filter wheel it is often not possible to use two filters in front of a ultrawide lens with a lightweight mattbox.
Also in general optical quality drops off more with the use of front of lens filters compared to rear lens filters.
Then there are the reflection issues of point sources.
Also no matter what size the front element of the lens you are using, you have a clean pristine filter that fits!



Mike Brennan

 

[Michael Brennan]

IMO, the fixed-lens version is the only Scarlet on which built-in NDs would make sense. Then again, incorporating them would mean more crap in the optical path that could be undesirable at times. I would prefer mine without any built in. For dynamic lighting conditions as you describe, there are other means by which to handle that.

Jeff, am I missing something, there appears to be little or no optical disadvantage/crap reported regarding filter wheels since its introduction twenty five years ago in 2/3 inch prism cameras.

Is a single sensor camera likely to be any different?

The only negative thing I can recall is the concept of a backfocus shift if all the filters were not the same thickness. This proved to be a red herring, driven by those early f900 users some of whom were inept at setting and checking backfocus.



Mike Brennan

 

[Dominic Jones]

I have to say, I can't see any reason to not include a filter wheel into all 2/3" models.

Obviously it's not practical over that size, but also it's a case of the market you are catering to - most (not all, of course, but a lot) of the people who buy/rent 2/3" models will be used to having filter wheels/selectors in their cameras, coming either from ENG backgrounds or indie filmmaking with 1/3" camcorders or similar.

Whereas, the majority of the larger format users will be used to cine-style shooting, where external filtration is the norm...

So... It makes perfect sense to me (above and beyond the practical size issues) to put filter wheels in the 2/3" models but not in the larger format models. No?

Dom.

 

[Jeff Kilgroe]

Any time you introduce optical elements into the light path, you just gain more stuff in the optical path... I guess what my real point is that adding a filter system in front of the sensor increases the minimum possible distance from the mounting surface to the sensor, in turn decreasing the number of options for lens mounts. And it's just one more thing to collect dust. On a fixed lens model these are essentially non-issues. I would probably welcome an internal ND system on the fixed lens Scarlet as long as it doesn't nave an impact on the size of the camera. If it will add any perceptible size difference, then drop it. Maybe my lack of enthusiasm comes from existing internal ND systems on the market... I often find they don't provide the coverage to work in many situations and they are only a small convenience when they happen to have the right light blocking properties needed at the time.

For interchangeable lens cameras, the above mentioned issues would be of concern. The upcoming DSMC cameras hold a lot of appeal to people with varied lens collections. The ability to swap to theoretically any form of lens mount is huge and adding another something or other into the optical path could interfere with certain mounts.

ND filter systems on interchangeable lens cameras are something that requires regular maintenance and cleaning. Just one more set of moving parts. Like the OLPF and sensor block, any filter in the optical path that occasionally becomes exposed while changing lenses is vulnerable. Just as you mention that there have been F900 owners not checking back focus (and believe me, there still are), there are also those who don't perform routine cleaning and maintenance of their gear.

My most common style of shooting is essentially documentary style. I do mostly corporate, industrial, EFP, very little narrative anything. I see the appeal of built-in ND filters, but have yet to come across any implementation that actually delivers the goods. With current CMOS cameras like the EX series and RED, any internal system, to be 100% effective would have to cover all the common values: .3, .6, .9. 1.2, 1.5, 1.8. And also provide an IR cut option, which would be very very difficult in an internal optical path implementation since most effective IR cut filters are mirrors. It would have to accomplish the above range without stacking more than two at a time in most situations to avoid any unwanted aberrations.

...I have yet to see an internal ND system that does any better than simply stacking two polarizers in front of the lens and dialing the amount of light blockage I want. In fact, I often wonder why an opposing polarizer implementation for internal, truly variable, ND filtering is not more common.

 

[Dominic Jones]

Perhaps a matter of personal preference/experience, but I have never had a problem with the internal filtration implementations on DigiBeta/HDCam cameras I've used, which is most of the Sony cameras and a smattering of others - all utilising interchangeable lenses, of course.

The exception to that rule is the EX-1/3, which for some reason known only to God and Sony do not include a clear filter in the "off" position, causing backfocus issues. There really is no need at all for this problem to exist, and I can't see any problem with inbuilt filtration in a 2/3" interchangeable lens Scarlet if properly implemented - but that's just my 0.02...

Now, whether or not it could cause problems with PL-mount 16mm glass is perhaps an issue - but my thinking is, if there's enough room in there for a spinning mirror and shutter assembly, then there must be room for a filter assembly. But that is, to be fair, total speculation on my part...

Cheers!
Dom.

 

[Gerald Menclik]

maybe it's just because all the brains have the same enclosure, so the 2/3 won't have a filter wheel ..... changing the enclosure between the 2/3 and the 35s wouldn't make things easier for development and construction of the brains ..... not to speak of the different programming for the fpga ...

just thoughts .....

 

[Michael Brennan]

If it was built like Viper, Sony, Panasonic the assembly would not require any maintenance and in fact offers protection for the anti aliasing filter which is glued to the sensor.


It seems possible that it would have been possible to fit a vertical sliding ND in Red.


Mike Brennan

 

[Joseph Ward]

No ND, please.

 

[Joe Picard]

yep built in ND is good in the same way a zoom is good. Makes sence to have them together.

Optical quality; you don't have to use it just because it's there, don't forget were talking about a zoom lens situations not a prime situation. Speed and ease is already the more important decision here.

 

[Wayne Morellini]

When I was investigating a way to handle latitude for my lens adaptor, I concluded that a variable density filter was the most convenient compromise. I came up with an number of different designs, but a design with a relatively clear optical path is possible. So they should explore this in the fixed lens camera.

The problem with many variable adaptors is that they do not present a clear optical path, and polarisers, polarise, which is fine, if you want that.

If they anted to include it on the other cameras, they could add it to the lens (actually add brain control to the lens as well, like many still cameras have done). But there is another option, but too late for now. There is a distance between the mount on the sensor. You could either have the mount removable and replaceable, and sell mounts with brain controlled variable ND filter in them, or insertable variable ND filter mechanism in behind the mount, between the lens and the sensor, so any lens could be used in theory.

There is another option I was thinking about using, but I do not know if you can get a material with enough optical purity. An electro-chromatic material could be used.

The best options are to build it into the brains/mounts or build it into the Red lens (with brain controlled optional auto functions, which increases their value as more all round versatile lens. One thing you generally are going to need, is ND filters.