Wanted: more latitude

[rawfa]

Hi guys,

I didn't really know where to post this, so I hope here it's fine. Here's the deal, I've been "studying" and trying out 35mm adapters for years. Initialy I was curious about it because of the amazing possibilities of having DOF with digital video, but after years looking at diferent adapters' footage one thing that really stroke me as REALLY amazing is the fact that some of these adapters (particularly the G35 and the Redrocks') seem to increase the cameras' latitude drasticly. Weather the increase of latitude is aparent or real is beyond the point, since when you look at the footage what you see is a very aparent increase in latitude (good enough for me). I'd like to know if there's any other way to do this, maybe even using some of what is being used by Cinemek and Redrock but in a different way, without the adapter, for people who just want more latitude and don't necessarily want DOF.

[dan]

Someone (i forgot the name) had the idea of placing a glass made of many cells (down close to pixel levels) of this:
http://sun-may.com/index_adwf.htm
in front of a CMOS (or just behind the lens of a camcorder).
End result: the brighter areas of the picture caused the cells (in that zone) to darken, while the other ones remained clear. Auto compensating gradual ND filter down to pixel level.
What do you get?
An image full of details and colors in both highlights (not washed-out or "blooming" anymore ) and shadows. If I remember... the “thing” had an adjustable range so you can get the contrast as desired.

[rawfa]

That is a very interesting idea and this is something that can be bought at ebay very cheap. Did you actualy see footage from it? I can't do it, but I'm pretty sure there's a lot of people here who could turn this into a standard filter to be screwed into any camera. I once tried the Tiffen ultracontrast but the image was very pasty and far from expected. It would be insteresting to find out what exactly is responsible for the increase in latitude on these adapters. The ground glass? The difuser?...A filter that could increase latitude the way these adapters do would be a huge deal.

[Forrest Schultz]

with the idea of the welding helmet lens materiel, im not sure, but with all the electronic welding helmets i used, the shade has a green tint to it all. so even though it auto darkens, its a very filtered green. also, i think the filters are only capable of being engaged and disengaged, and the whole area of the lens is darkened and then let off whenever a bright light source is taken away. im not sure if its capable of doing certain areas.

[rawfa]

Well, back to square zero. Maybe Jonathan or Brian could shed some light here. Hey, Dan, this is something you should look into for the Felix ;-)

[Yas Kassana]

It's not real latitude it's psuedo-latitude. With good adapter like redrock and g35 they use some seriously good glass, achromat, pcx and a serious good gg that diffuses the light properly. Essentially what your seeing then is the quality of the lense, so if you have nikon 50mm 1.8 (reference kenrockwell.com) the lense itself is renowned for excellent colour, bokeh and great contrast. So what you essentially seeing is the the colours the a good lens is giving. In order to do that the nikon lense has to bypass some seriously GOOD glass to achieve those colours.

[Policar]

Shallow DOF mixes background colors together and they look softer, thus the impression of greater resolution is given. (This is straight from a cinematography textbok.)

Most 35mm adapters work as a "controlled flare" which brings the lower values up somewhat (similar to raising the master ped.) Using a Digicon or Ultracon filter should do the same thing. The lenses can also lower contrast, but generally not in the direction of more highlight detail.

(And I've shot 35mm side by side with dvx using a bunch of adapters...most are similar in these regards.)

[rawfa]

I checked out the digicon and the simulated image looks really good (then again, it's simulated). Do you have any footage? Like I said before, I tried out the Tiffen Ultracontrast and I found it a total dump. The problem is that I don't see any screw-on digicon filter and I'd like to be able to use the filter with my Brevis35...which
is going to be hard if I have to use the filter on a mattebox.

[Policar]

If you're already using a 35mm adapter, you're already getting the controlled flare effect as much as you need it, imo. My best advice would be to use light intelligently, although it's a lot of work:

If you shoot indoors, use diffusion when necessary to avoid blow outs. Put ND gel (or ND CTO or screen door material) over windows to avoid major blow outs unless you like them.

If you shoot outdoors, avoid mid day but failing that use shallow focus to blur the highlights behind the subject and use reflectors (and possibly a net over the subject's head) to soften the light on the subject.

Then in post, bring down the blacks a bit, bring up the mids, and bring down the whites in the color corrector 3 way. Works for me.

[PaPa]

which one are the whites again? the actual term?

[Policar]

Highlights, my bad.

[MalcolmOng]

Sooo i can actually get the lattitude associated with a 35mm adaptor using a digicon filter? Hmm...well the brevis costs aobut 795, and the digicon costs 149, and i need a mattebox, so assuming i go with the indiesnap, it'll cost half as much!:D Maybe i'll consider that...

[rawfa]

Sooo i can actually get the lattitude associated with a 35mm adaptor using a digicon filter? Hmm...well the brevis costs aobut 795, and the digicon costs 149, and i need a mattebox, so assuming i go with the indiesnap, it'll cost half as much!:D Maybe i'll consider that...

If you don't need the DOF I'd say that would be the natural course to go.

[rawfa]

I have a Brevis35 and even though it is a great adapter, it doesn't increase the latitude as much as I'd like (Dennis is making some diffusion changes that make fix that...hopefuly!). I've seen A LOT of footage from Redrock and Cinemek and ther's a lot of people using cheap lenses and not primes, and the footage looks cinematic straight out of the camera anyway. So, I think it really has something to do with either the ground glass or the diffuser. The question now is: how to build a screw-on filter with the same material they use on their adapters? This is a tip for Cinemek, Redrock and Cinavate too. A filter like this would be a huge seller.

[Yas Kassana]

it would be a big seller, but wouldn't there be more light loss?

[rawfa]

it would be a big seller, but wouldn't there be more light loss?

Then it would be up to the user to see if he is whiling to loose a little light or not. People who buy 35mm adapters know they are loosing some light and they buy them anyway. I think that if the product really works and if the light loss is not extreme most people wouldn't mind that much.