Resolution of IMAX lenses at MTF-50

[Jonathan Ruiz]

What is the lp/mm resolution of IMAX lenses at MTF-50? MTF-60 would be better in my opinion (if you have that info, but you don't have to give it out).

[Tyler Purcell]

Many of the IMAX lenses are just Hasselblad medium format lenses converted. So I'd start looking at Hasselblad specs first. 

[Jonathan Ruiz]

1 hour ago, Tyler Purcell said:

Many of the IMAX lenses are just Hasselblad medium format lenses converted. So I'd start looking at Hasselblad specs first. 

What specific Hasselblad lenses are they? What were the ones they used for Dunkirk?

I know that you could look up the focal lengths and apertures on websites such as the ASC website, but they didn't mention the specific lenses that they used. Same thing with the Mamiya lenses used for the Dark Knight Rises.

Also, there are no specs that I am aware of for the Panavision Sphero 65 lenses.

Maybe I'll just look up the sharpest 6x7 Hasselblads and Mamiyas at the focal lengths mentioned in the ASC and British Cinematographer websites, but I am not sure where to find info on the Panavision Sphero lenses on lp/mm resolution or MTF.

Edited June 26, 2021 by Jonathan Ruiz

[Tyler Purcell]

22 hours ago, Jonathan Ruiz said:

Maybe I'll just look up the sharpest 6x7 Hasselblads and Mamiyas at the focal lengths mentioned in the ASC and British Cinematographer websites, but I am not sure where to find info on the Panavision Sphero lenses on lp/mm resolution or MTF.

Yep that's what I'd do. Basically IMAX is going to be mostly medium format lenses. Nothing else to my knowledge really covers the format. So it was easier to simply make the cameras work with those lenses. 

There are a lot of 5 perf 65mm lenses available. Zeiss/Arri have a kit for the Alexa 65. Panavision have a few options, not just one. I bet if you looked hard enough, you'd find quite a few options. 

May I ask, what are you trying to achieve by looking for the MTF? 

[Dom Jaeger]

Not sure what use they are to be honest, and they may have been modified to be faster or focus closer, but here are data sheets on what I believe were the main IMAX lenses used on Dunkirk:

http://www.hasselbladhistorical.eu/pdf/lds/FE50.pdf

http://www.hasselbladhistorical.eu/pdf/lds/CF80.pdf

You won’t find MTF data on Panavision lenses because they’re not for sale and cinematographers generally don’t care about MTF graphs - they care about what the image looks like. Some lenses would have pretty ordinary MTF charts, particularly if they’ve been detuned, but in the right hands they can look fantastic. At the other end of the scale, Primo 70 lenses are as highly resolving and aberration-free as any lens I’ve ever seen.

[Jonathan Ruiz]

On 6/26/2021 at 8:47 PM, Tyler Purcell said:

 

 

On 6/26/2021 at 8:47 PM, Tyler Purcell said:

I bet if you looked hay I ask, what are you trying to achieve by looking for the MTF? 

I want to see if I could match or surpass Kodak IMAX film in the blue layer of the film using the sharpest medium format or Panavision Shero 65 lens used at its sharpest aperture with a full-frame 8k digital sensor using full-frame lenses with vista vision sized image circles (no higher than MTF 40 on either film/sensor + lens system). I'm not trying to shoot a movie or anything, I'm just curious.

[Jonathan Ruiz]

On 6/27/2021 at 4:02 AM, Dom Jaeger said:

Not sure what use they are to be honest, and they may have been modified to be faster or focus closer, but here are data sheets on what I believe were the main IMAX lenses used on Dunkirk:

http://www.hasselbladhistorical.eu/pdf/lds/FE50.pdf

http://www.hasselbladhistorical.eu/pdf/lds/CF80.pdf

You won’t find MTF data on Panavision lenses because they’re not for sale and cinematographers generally don’t care about MTF graphs - they care about what the image looks like. Some lenses would have pretty ordinary MTF charts, particularly if they’ve been detuned, but in the right hands they can look fantastic. At the other end of the scale, Primo 70 lenses are as highly resolving and aberration-free as any lens I’ve ever seen.

Thank you so much! This really satisfied my curiosity!