Lens Vs. latitude

[Jose Poernomo]

Is it true that different lens has different latitude ?

Jose

[Martin Weiss]

What do you mean by latitude?

Do you mean the focal point, i.e. where the lens focuses on the film plane/sensor?

In that case, the focal point depends on the lens mount; but within each leans mount it should be very consistent.

I'm sure our Lens Connoisseur will have much better intel than me ;)

[Jose Poernomo]

Im sorry for not being clear... I meant latitude as in dynamic range.

I just read an article on AC January edition.. Shane Hurlbut stated that Primo lens has 1.5 stops more latitude in both directions, compare to still lens.


Jose

[Stephen Williams]

Hi,

A lens with the latest modern coatings will be able to hold more of a range of contrast, Cooke S4's would probably beat most still camera lenses as well.

Stephen

[Vico Martin]

IMHO in digital cinema the sensor sets the limit of DR.

[Jose Poernomo]

if that's the case... how's RPP compare to other major player, is there any noticeable difference ?

I also think today digital sensor limits DR, but this DP stated he can noticed 3 stops more latitude on Primo, while using 5D Mk.II


Jose

[LEON]

if that's the case... how's RPP compare to other major player, is there any noticeable difference ?

I also think today digital sensor limits DR, but this DP stated he can noticed 3 stops more latitude on Primo, while using 5D Mk.II
Jose

Incredible !!! Very hard to believe !

[Jose Poernomo]

Incredible !!! Very hard to believe !

:)
read American Cinematographer, January edition.


Jose

[LEON]

:)
read American Cinematographer, January edition.


Jose

Thank you, i just read it and still do not understand, even if so many lenses
inside a zoom can lower the contrast compared to a fixed focus lens, I don't see 1 and half stop in both directions !
But , we learn every day !

[rod bradley]

I haven't seen the article but I think there is a lot of perceptual subjectivity involved in many evaluations of dynamic range that aren't actual technical tests. And of course great lenses and great coatings definitely increase the impression of dynamic range. And will get the most out of a sensor, along with proper exposure of course.

[Dan Kanes]

Poignant conversation.

I am one to believe that a lens does not affect latitude as it is mentioned in the article, but I do believe that different lenses have a strong impact on Contrast and perceived dynamic range.

Here is a nice quote, borrowed from research by SmokeCat20 on DVXUser:

One possible theory could be the way the lens handles and redirects light. Here's an interesting thing Ira Tiffen, of Tiffen filters, had to say about a concept to increase the "appearance" of range via glass:
(from: http://www.cinematography.net/edited...ConFilters.htm)

"The concept centres around wanting to render highlights darker than they would otherwise appear, to show more highlight detail, and to specifically do so in a manner that fits in with the often-used practice of maintaining a particular T-stop to better maintain lens sharpness and depth-of-field characteristics. Used the way we suggest, not compensating for exposure, the filter will darken highlights by one stop, which, if it were just an ND filter, in darkening everything by one stop you would not see a real change in contrast.

The difference is that the low contrast component will still lighten shadows. The net result is that you have raised shadow luminance AND reduced highlight luminance simultaneously. You could accomplish this by closing down a stop and using a Low Contrast filter, but you would have to make the stop adjustment, which may be undesirable. When you compensate for the one stop of the Soft Con filter, you are effectively taking advantage of it as an ND filter to allow for a larger lens opening while retaining its ability to lighten shadows and reduce contrast.

Think of exposure adjustments as able to either raise or lower luminance levels of everything. Highlights up, shadows up; highlights down, shadows down. The only time this results in an apparent increase in contrast is in parts of the scene that are either black from underexposure or white from overexposure; in either instance, adjusting exposure will bring out more detail and thus more apparent contrast. But contrast is still the difference between the luminance levels of highlights and shadows, and to effectively increase this you may need to be able to treat both differently, as I have written earlier.

Grads and attenuators will allow overly bright areas to come closer to being properly exposed at the same exposure that you would use for getting good detail in otherwise darker areas, such as with an overly bright sky- a ND 0.6 grad will usually be enough to allow good detail in the average bright sky as well as in the darker foreground. However, these filters will not have an increasing or decreasing effect on actual contrast apart from the particular circumstances of apparent contrast changes I refer to above."

[jonnycom]

It depends on the longitude.

[Sanjin Jukic]

http://www.hurlbutvisuals.com/images/_new102009/IMG_0809.jpg
A member of Bandito Brothers the Los Angeles-based production company
carry 7D(or 5D) mounted on O'Connor head/tripod with Panavision Primo zoom at this desert location.


Here is the quote from AC/0110 article
"How Digital SLRs Can Change the Way We Make Movies"
by Shane Hurlbut, ASC
when he talked about the 7D's latitude performance (pages 93-94):

"The 7D’s smaller sensor results in
greater depth-of-field compared to the
5D, meaning you can shoot at a T2
instead of a T5.6 and still have a fighting
chance of keeping things in focus. On
both cameras, though, the latitude is
pretty extraordinary, and I’ve learned that
you can’t use a light meter. I’ve been in
situations where my meter read T.7 and
we were exposing at a T4, and the subject
looked like he was keyed.
Shooting with still lenses, I was
seeing about 5½ stops below key and
about 3½ stops over. When we went to
the Primos, the latitude increased by
about 1½ stops in both directions. After
seeing the Primo glass combined with the
5D’s sensor, we’ve decided to shoot the
remainder of Easy Day — even the
sequences we’d planned to shoot with
35mm — with a combination of the 5D
and 7D."

AC/0110 LINK>>> (http://www.nxtbook.com/nxtbooks/ac/ac0110/index.php)