Mathew Collins

Thank you Stuart,Adrian,Justin and Gregg.

Ultra-sonic is from any specific company? Any issues with Disto in lowlight conditions?

Is the following one a Laser rangefinder? http://www.amazon.in/Bosch-GLM-Laser-Rangefinder-Blue/dp/B0033RU8MM?tag=googinhydr18418-21&tag=googinkenshoo-21&ascsubtag=ac6fa0f8-c4a8-4b29-97f3-5cc9d71571a9 http://www.amazon.in/Bosch-DLE-Laser-Rangefinder-Blue/dp/B002LJF7YM?tag=googinhydr18418-21

Hi, Is there any distance measurement equipment available to help focus puller to know the distance to subject? Please share your inputs. -Mathew Collins.

Just comparing this with David Mullen quoted on Jun 18th, "A 25mm at f/2.8 focused at 5 feet, let's say, has a different depth of field on a smaller format because if shown on the same sized screen as a larger format, the image is being enlarged more so you have to use a more critical Circle of Confusion figure." Can i put it in this way? If i am planning to project an image which is shot in 16mm onto 70mm format, image being enlarged so we would use use small circle of confusion while shooting in 16mm.

Thank you David and Brian. I am trying to understand it.

Does that mean 'small Circle of Confusion figure'? But my understanding was 'critical=urgent'.

Thank you David. My question is not 'What is circle of confusion?' but 'more critical Circle of Confusion figure'

Thank you Mark. What is the meaning of "so you have to use a more critical Circle of Confusion figure"?

> A 25mm at f/2.8 focused at 5 feet, let's say, has a different depth of field on a smaller format because if shown on the same sized screen as a larger format, the image is being enlarged more so you have to use a more critical Circle of Confusion figure. Not able to understand the this part.

Thank you Dan. I am aware of the factors distance from the subject, t or f stop, focal length, light & composition.

Adding to the above question, a document "Sensor Size and Field of View of the Primo 70 Series of Lenses" in the following link says, http://panalab.panavision.com/panalab-reference-library?page=4&title=&field_document_tags_tid[0]=228 Sensor size has no effect on the depth of field. A 21mm at T2.8 will always be a 21mm at T2.8, whether it’s on a 70mm camera, a Red Dragon, or a Super 35 camera. However a 27 mm on a Red Dragon will give you the same Field of View as a 21 mm on Super 35, and using a longer lens gives you less depth of field. So at the same camera position and with the same framing, a filmmaker will get less depth of field on a Red Dragon than on Super35, but only because he has to use a longer lens. Please provide your views.

Hi, Is there any relationship between Sensor/Film size and depth of field? The following video says, Sensor size has an effect on the depth of field. -Mathew Collins.

Thank you David, Adam.

I missed '4-perf 35mm/ Super-35'. While using spherical lens on the cameras like F65, Red Dragon, Does the loss of field of view exists compared to 4-perf 35mm/ Super-35? Only RED WEAPON 8K VV(VistaVision Dragon Sensor) - 33.60 mm x 21.60 mm and RED WEAPON 8K VV Ana(Anamorphic) - 33.60 mm x 21.60 mm having height of the sensor greater than 18.59mm. Does the height comparison of the sensor with 4-perf 35mm is relevant only when shooting in anamorphic?

While using spherical lens on the cameras like F65, Red Dragon, Does the loss of field of view exists?

Thank you David, Satsuki.

https://www.vantagefilm.com/en/news/first-hawk65-anamorphic-lenses-meet-the-red-weapon-8k-in-los-angeles-10510 In the above link DP Markus Fördere is testing HAWK65 Anamorphic Lenses on RED Weapon 8K. Red Weapon is in 2-3 models like HELIUM® 8K Super35, RED DRAGON® 8K VV™ as well as VV Anamorphic Would he using the any of the 2nd or 3rd model?

Hi, Is it possible to use lens designed for 65mm cameras on super 35 cameras? Got this questions while going thru the following link. https://www.vantagefilm.com/en/news/first-hawk65-anamorphic-lenses-meet-the-red-weapon-8k-in-los-angeles-10510 Please share your inputs. -Mathew Collins

Thank you David. Red Epic MX image circle is 31.4mm and Zeiss Ultra Primes 16mm Image Circle is 33mm. I think the sensor would fit inside the image circle.

Hi, Would that vignetting will be visible in the Camera LCD screen or while looking thru view finder? Now I remember one issue came up while assisting a DP in the last movie. We were using Red Epic MX and Arri Ultraprime lenses. DP asked camera assistant to change the lens into 16mm and he encountered some issues with the lens. But not sure the issue is about vignetting. I think after that he did not use that lens. We were shooting in 2.4:1. The following link says, "S35 Mysterium-X sensor is 30mm x 15mm. So to cover the entire sensor, you would need an image circle of 33.54mm or call it 34mm.". I am not able to find out the diameter of the image circle formed by Arri Ultraprime 16mm. http://www.reduser.net/forum/showthread.php?41080-Definite-Image-Circle-Size-for-Epic-5K-Sensor Would the image circle of Arri Ultraprime 16mm cover Red Epic MX?

Thank you David, Michael. As David pointed out, I was confused with 35mm format and Ø 35 mm. Again that opened bunch of new knowledge. Thanks much.

Thank you D Thank you Dom. >Optimo extenders will increase the image circles of those zooms to at least a 35mm diameter. In this case is 35mm is bigger than Super-35? For all the lenses by adding an extender Super-35+ expands to Ø 35 mm.

Hi, I was just going thru some lens specifications in the following links and confused. OPTIMO SPHERICAL LENS 15‑40mm says, https://www.angenieux.com/optimo-compact-lens-zoom-15-40/ Lens specification gives, IMAGE COVERAGE: S35+: 31.4 mm diagonal Image coverage: S35+ (Ø 31.4 mm), expanded to Ø 35 mm when used with Optimo extenders (more info in DOWNLOAD section) OPTIMO SPHERICAL LENS 28‑76mm https://www.angenieux.com/optimo-compact-lens-zoom-28-76/ IMAGE COVERAGE: S35+ 31.4 mm diagonal Image coverage: S35+ (Ø 31.4 mm), expands to Ø 35 mm when used with Optimo extenders (more info in DOWNLOAD section) OPTIMO SPHERICAL LENS 45‑120mm https://www.angenieux.com/optimo-compact-lens-zoom-45-120/ IMAGE COVERAGE: S35+: 31.4mm diagonal Image coverage: S35+ (Ø 33.34 mm), expands to Ø 35 mm when used with Optimo extenders (more info in DOWNLOAD section) OPTIMO SPHERICAL LENS 24‑290mm https://www.angenieux.com/optimo-long-lens-zoom-24-290/ IMAGE COVERAGE: 35 mm academy – 30 mm diagonal With extenders, image coverage becomes S35+ - 31.4 mm diagonal Image coverage up to S35-3 perf. (Ø 30 mm), expands to Ø 35 mm when used with Optimo extenders (more info in DOWNLOAD section) 1. Does the corresponding focal length increases while adding an extender? 2. Does the image coverage decreases by adding and extender? 3. What is the difference between S35 an S35+ ? 4. Is S35+ bigger than 35mm academy? 5. Why the image coverage of 45‑120mm on S35 is 33.34 mm and others 31.4 mm? 6. By adding extender to some lenses 35mm academy changes into s35+ and vice-versa? How? 7. By adding an extender on 15‑40mm or 28‑76mm or 45‑120mm, S35+ changes to 35mm academy but for 24‑290mm 35mm academy to S35+? Please share your thoughts. -Mathew Collins.

Thank you David, Satsuki and Adam.