anamorphic lenses...

[Filip Plesha]

I have a few questions for you cinematographers about the use of anamorphic lenses.Since there are no lenses like those in still photography (well

maybe they were used but not to my knowledge,at least not in standardized

processes) i have never seen one nor do i know all the facts about them.

So i'll open this topic in hope that someone can explain those things to me:

 

First of all...are those special lenses or are they just regular primes with

some anamorphizers attached?

How do they look like? Are they round like sphericals or some other shape?

 

And now some exposure questions.

Why are they always considered to be slower? Is it because people are

afraid to open the aperture to much because of the distortion or is it

because of some inability to pass enough light through a glass designed

in that manner?And if the second is true,how much less light they pass through

in comparison to spherical lenses? A stop less maybe?

 

All i have seen from anamorphic photography are actual film prints

in cinema,which are not really good enough to judge the actual qualitty

of the original elements.So my question is, can anamorphic film look sharp?

Is it possible that if you use a small aperture opening like 5.6 that it looks like it was spherical photography, only wider? (not paying attention to the grain difference)

[Fredrik Backar FSF]

Can u get Anamorphs sharp? Most definitely!

Made print of film shot on Hawks the other day and it was as sharp as u get.

 

The lenses differ in size but but are on the whole somewhat bigger. Pana primos....

 

Keeping the F-stop high is inthe fact that the depth of focus is inheretly shorter in anas. Plus, it lessens the possible focus loss in its peripheral ares.

 

The anamorphic element may or may not be placed as the front element the of the lens. Internal ana-element does give less distortion when using a wider lens.

 

On the hawks for instanse, The 40mm prime with front ana made reality look like a barrel on the sides, whilst the zoom starting at 46mm and internal ana looked very nice and straight.

 

One could also add that, for instanse, a 50mm lens is more of a portrait lens then a regular 100mm would be as the aspectratio 2.35:1 of course differs from the usual 1.33 framing

 

Take care! :D

[David Mullen ASC]

Anamorphic lenses are spherical lenses with an anamorphic lens element added, front or back. Usually front for wide-to-medium primes, back for zooms and telephotos. The element looks like a cylinder of glass cut in half.

 

There is no real light loss to calculate when exposing. There are fast anamorphic lenses too. It's just that since the 2X squeeze makes the lens see double the width, people tend to use longer focal lengths to compensate -- i.e. instead of using a 20mm anamorphic to get the horizontal view of a 10mm lens, they might use a 40mm anamorphic to get the horizontal view of a 20mm lens. So depth of field characteristics are due to the fact that people are using longer focal lengths.

 

Also distortions reduce as you stop down, hence why some people don't like to shoot wider than an f/4.

 

The main reason anamorphic photography looks better on the big screen is that the overal size of the negative and print area used are larger than 1.85 so it enlarges better. Super-35 uses anamorphic prints, but the negative area used is about 40% smaller because of the cropping to 2.39 : 1.

[GregIrwin]

Keeping the F-stop high is inthe fact that the depth of focus is inheretly shorter in anas.

Take care! :D

To be precise, depth of field is the same from millimeter to millimeter. For example, a 100mm spherical will have the same depth as a 100mm anamorphic. It is the angle of view that changes wider with anamorphic thus making us use longer lenses to get the same angle of view with a spherical lens. That's why the depth is more challenging.

[Filip Plesha]

Thank you guys.

 

About the negative area,yea,i have been drawing and calculating

negative areas my self to see how it differs from super 35

or regular 35 before.

 

But even if this is the only widescreen 35mm process that uses the whole frame

in todays cinematography it is allso the format that uses the largest enlargement of

the image horisontally.

 

So actually the grain in anamorphic is wider than any other format,

but the height is still the same making it a lot less visible.

[Fredrik Backar FSF]

Learned something here today then. Always thought it was that the focaldepth was less overall...

Thank you then :D

[Filip Plesha]

And one more thing...

 

how would you compose a list of anamorphic lenses by different manufacturers

by their sharpness (which would be 1st in the list for its sharpness and which

would be last etc..)

 

 

I have allso read once that hawk lenses have white flares,

and i think panavision anamorphic lenses have blue flares since

i've seen them on many films shot with panavision cameras (am i right here?)

What about other lenses? What kind of flares do they have?

And is it a good way to indentify anamorphic lenses relying on the color of flares?

[Kevin Zanit]

All lenses flare slightly different, that goes for different lenses in even the same product line.

 

The Primo Anamorphics have a blue flare, and the E series have a white flare (?) (could be wrong).

 

It comes down to all the pieces of optics in a lens, and how they interact with each other and the light.

 

 

Kevin Zanit

[David Mullen ASC]

Anamorphic photography doesn't actually have "larger" grains horizontally. The size of the grain is the size of the grain -- what makes it larger or smaller is the degree of enlargement. It gets doubled in width when projected.

 

Think of it this way -- the grain in the Super-35 image is enlarged vertically by twice to become an anamorphic image... and then the anamorphic projector lens doubles it in width horizontally. So that one grain is basically twice as large both vertically and horizontally, while the grain in the anamorphic image is only enlarged horizontally.

 

Either way, Super-35 blown-up to anamorphic is always grainier than true anamorphic photography given the same film stock, exposure, etc.

 

The only leveller, besides using slower film with Super-35, is when you are comparing a digital intermediate blow-up from Super-35 to an I.N. and you make all your release prints from that I.N. or make multiple I.N.'s from the same digital master -- compared to making release prints of anamorphic photography from a conventional I.N. created from a I.P. In this case, you are comparing fourth generation anamorphic photography to essentially second generation Super-35 photography (since the digital step does not count as a generation since there is no grain build-up and the output can have first generation grain). Of course, one could do a digital intermediate with anamorphic photography as well... But in that case, digital intermediate at 2K resolution might blur the differences in quality between anamorphic and Super-35.

 

Also, compared to 1.85, the projected area of an anamorphic print generally has to be enlarged less to fill the same height screen.

[Filip Plesha]

David of course i know that,read my post again:

 

"But even if this is the only widescreen 35mm process that uses the whole frame

in todays cinematography it is allso the format that uses the largest enlargement of

the image horisontally.

 

So actually the grain in anamorphic is wider than any other format,

but the height is still the same making it a lot less visible."

 

As you can see i did mention the horisontal enlargement,so

of course i know that grain is streched (enlarged horisontally twice),

I don't think anyone would think that the grain has that

shape in the print.

[Rob Belics]

I got into this argument with this guy on a dv forum. Why I go to this place I'll never know.

 

He's got me spinning in circles with his logic but I want some assurance that I'm correct in my thinking. I hope I say this right because my head is spinning right now.

 

He claims that Techniscope, being shot with 2-perf, is half the resolution of 4-perf Academy so that makes Techniscope S16 quality. I'm trying to tell him that, with the widescreen process, you don't use about one half the negative (vertically) so it works out the same and the horizontal resolution is the same.

 

He says shooting anamorphic more than doubles the resolution. Again, I say resolution is determined by the size and quality of the negative not whether the image is squeezed onto it.

 

He says Super35 is much more common than anamorph. I say you're just as likely to find one as the other though Super35 may have gained a lead.

 

He says Super35 is a 3-perf process but I say it can be four and usually is.

 

'scope is never masked at the theatre, ony 1.85 is.

 

I think this guy knows enough to be dangerous but maybe I'm full of it or maybe I'm just tired right now.

[Filip Plesha]

Horisontal resolution of techniscope is the same as regular 35mm,but

the enlagement is bigger,and it is worse than super 35.

 

Try to calculate or draw on a piece of paper a screen

and by drawing images and calculating a bit figure out

how does s16 compare to techniscope.

 

I think when you take away a few milimeters of techniscope

just to match the s16 aspect ratio you would get similar results,

but still teshniscope would be a bit better,it would have maybe 2

milimeters more in image width.

[Mitch Gross]

Rob,

 

You're basically right and he's basically wrong. It's really simple math and anyone who has ever looked at the actual material or measured it out knows what the differences are. I liken this type of Internet knowledge to an old Steve Martin joke: In college they teach you just enough philosophy to fu** you up for the rest of your life.

 

You have no idea how many people read a little something in an article or on a webpage somewhere and then try to argue with me that the earth is flat.

[David Mullen ASC]

You were saying that anamorphic enlarges grain the most horizontally when actually the horizontal enlargement of the grain is the same for anamorphic versus Super-35 when blown-up to anamorphic PLUS the grain is enlarged vertically with Super-35 blown-up to anamorphic.

 

When composing for cropping to 2.39, you use about 2 1/2 perfs out of 4 in Super-35, versus 2-perfs for Techniscope, so there is only a minor difference in effective negative area.

 

I'm not sure if having twice the negative area exactly means the same thing as having twice the resolution but I guess you could say that. Sounds a little misleading though.

 

You can't really say that 2-perf 35mm is Super-16 resolution since they have different aspect ratios -- but even if you cropped 2-perf 35mm to 1.85 and compared it to Super-16 cropped to 1.85, 2-perf uses a larger negative area.

 

Super-35 has become more common than anamorphic especially if you consider most 35mm production for TV is Super-35.

 

Super-35 is mostly 4-perf for features and 3-perf for television, with exceptions.

[Filip Plesha]

This would be true if super 35 used 21mm wide image area.

but it uses 24mm and thus needing slightly smaller horisontal enlargement

 

Lets forget about printing qualitty losses for a second and speak theorethically

about enlarging the frames of the negatives themselfs to fill a cinemascope screen.

 

Here is how it goes:

 

You enlarge the anamorphic negative by some number N vertically and 2N horisontally to fill the screen. (where N would the linear (not the ratio of surfaces,but the ratio of lenghts) enlargement of the projector for a full 4 perf 21mm wide frame without masking)

You start with a 21mm wide frame and stretch it horisontaly twice treating it

like a 42mm wide frame with the enlargement of N.

 

then you take a 24mm wide super 35 frame and compensate by enlarging

everything by 1.75N to get the same effect of a 42mm wide frame enlarged by N

(horisontally and vertically)

 

So in the end you end up with 1.75N enlargement in height and

1.75N enlargement of width compared to 2N enlargement of widht of

an anamorphic negative and 1N enlargement of height where again

N is the linear enlargement of a standard 4-perf 21mm wide 35mm film frame

without any masking centered in the middle of a cinemascope screen

 

When you multiply horisontal and vertical enlargements

for both anamorphic 35 and super 35 masked you get

this: for anamorphic negative total enlargement (versus linear) of the frame is

2N-square,and the total enlargement of super 35 would be 3.0625N-square

 

This is objective difference in enlargements.

 

 

I hope the text is not confusing

[David Mullen ASC]

I think you're just confusing yourself. It would be simpler just to compare total negative area used to create the 2.39 : 1 frame.

 

Either way you want to look at it, practically speaking anamorphic photography is noticably finer-grained compared to Super-35 when you make all other factors equal.

[Filip Plesha]

I'm not confusing myself at all.I think there is nothing confusing

about what i have said.

 

And all i have said with this is the same thing that you said,

and that is the fact that anamorphic has finer grain on screen.

So i don't understand what is the problem then

[David Mullen ASC]

The problem started when you said that anamorphic had the most degree of grain enlargement horizontally, which is misleading.

[Filip Plesha]

Well technically speaking,this is true,

but the fact that it sounds misleading is not really important

because in reality anamorphic looks better.

It's because the overall enlargement of super 35 is about 50% greater than

with an anamorphic frame

[David Mullen ASC]

It's misleading because the grain in an anamorphic print is not enlarged horizontally until it is projected, and therefore the degree of enlargement is dependent on projection size. If you compared 1.85 projection to anamorphic projection on a screen of the same width, with the 1.85 image being larger vertically, then the grain on the anamorphic print is not being enlarged more than the 1.85 print's grain.

[Filip Plesha]

Actually in my last post i forgot to consider the actual

exposed area of the image in a frame of a scope film

(it is not full 21mm wide,it is masked to about 19mm)

 

to see what i mean please download this little file,

i drew everything.

 

http://www.inet.hr/analogreality/new-5.jpg

 

Since in cinema scope films are framed so that only this

19mm image area (with a slight fade out on the edge) is projeced to

avoid having black area on the screen i matched only the

projected area of a scope film (not the masked area that is discarted

in projection)

 

Considering this,my last calculations were wrong.

The enlargement of super 35 is not 1.75 times more than the height

of a normal 35 frame,but 1.6

 

I hope you see now what i mean.

 

i used millimeters as lenght units in the program i did this and

then resampled the whole image to this size.

the proportions are the same.

 

The screen here is only a reference to show what the enlargement ratio

of scope versus super 35 should be.

In reality the enlargement is many times more

than seen in this picture of course,but that is not important because we are talking about proportions here.

[Filip Plesha]

Here is what i was talking about when i first started this topic.

I was surfing the net,and reading about fuji film stocks,

and here is what they say about one of their faster stocks:

 

"Its speed also helps to compensate for the increased stop required when using anamorphic lenses.... "

 

Are they really refering to using smaller aperture to compensade for

the gained deph of field with anamorphic lenses?

[Mitch Gross]

People generally stop down the aperture when shooting in anamorphic for two reasons. One is that the optical abberations are greatly reduced by using tighter apertures. The other is that a similar angle of view requires a longer focal length in anamorphic 35 compared to spherical 35mm. So to get similar framing one will have a smaller apparent depth of field because one is using a longer focal length. To counter this, a tighter aperture can be used. Make sense? What's important to note is that one doesn't HAVE TO use a higher stop, people just choose to.

[Jarin Blaschke]

What I think is odd is that anamorphic prime lenses are about as fast as sphericals - most open up to a T2 and the fastest i know of is a T1.1. There seems to be a misconception out there that these lenses require more light when in fact they really don't. To me, the appeal of anamorphic is in what is inherent to the format, ie: shallow depth of field, some distortion, etc.

[David Campbell]

depth of field is the same from millimeter to millimeter

I bow to Mr. Irwins practical experience in this matter but as the conversation seems to be turning on esoteric pivots I will point out that instead of circles of confusion you are dealing with elipses of confusion in anamorphic photography and dof will be a different sort of the same for each mm. Just for fun...

 

David Campbell

operator/ steadicam

dscmove@yahoo.com