Mini Primes 35mm equivalent and Scarlet 2/3" weight

[Andrew Rieger]

I was wondering if I could find out the 35mm equivalent size of the Scarlet miniprimes. I need to know what the widest mini prime is in terms of 35mm. Thanks.

Also, anyone have any idea how much the Scarlet 2/3" body will weigh? I am designing a special helmet rig and I am looking for a weight estimate.

 

[David Mullen ASC]

35mm equivalent in 35mm cine terms or Full-Frame 35mm still terms?

Multiply the Mini-Prime focal length by 2.5X to get the 35mm cine (Super-35) equivalent and by 3.6X to get the FF35 equivalent.

If the shortest Mini-Prime announced was 6.5mm, that's a 16mm equivalent in Super-35 and a 24mm equivalent in FF35, more or less.

 

[Andrew Rieger]

Thanks David. This is exactly what I was looking for. I am designing a helmet mounted camera rig that will use optical quality mirrors to provide the camera with a view the mimics the point of view of the actor, basically a face mounted camera that will not block the line of sight of the actor. I need to find a light weight camera solution and I am hoping that the Scarlet will not weigh too much and cause discomfort to the actor. Any lens suggestions? I am looking for a light weight wide lens that mimics the human FOV but one that has no distortion. Thanks again.

 

[Petr Dvorak]

...

Multiply the Mini-Prime focal length ... by 3.6X to get the FF35 equivalent.

....

Can somebody from Red tell us what exact number it is?
I heard about 3.8 (3.78) and also about 3.9 (3.93) and maybe 3.7 too.

 

[brian hanson]

so for anyone like myself who would like to see the numbers all at once:
6.5mm=16mm(super 35) or 24mm(full frame 35)
8mm=20mm(s35) or 28.8mm(ff35)
16mm=40mm(s35) or 57.6mm(ff35)
25mm=62.5mm(s35) or 90mm(ff35)
50mm=125mm(s35) or 180mm(ff35)

 

[David Mullen ASC]

...

Multiply the Mini-Prime focal length ... by 3.6X to get the FF35 equivalent.

....

Can somebody from Red tell us what exact number it is?
I heard about 3.8 (3.78) and also about 3.9 (3.93) and maybe 3.7 too.

Until we know exactly the dimensions of the FF35 sensor and the recorded area of that sensor, we can only use rough guides. If you say that a FF35 frame is 36mm wide, and if you say that the active area of a 2/3" sensor is 9.58mm (based on other 2/3" HD camcorders), then that's a 3.7578288X conversion factor if you are matching horizontal view (matching diagonals only works if both sensors are the same aspect ratio, but a 2/3" sensor is 1.77 : 1 and a FF35 sensor is 1.50 : 1.)

So I figure for now that a 3.6X, 3.7X, or 3.8X conversion factor between 2/3" and FF35 is good enough for now. Besides, prime lens sets rarely come in focal lengths that perfectly match the conversion factor anyway, there will always be a few millimeters difference unless you use a zoom to get exactly the correct number.

 

[Jeff Kilgroe]

Keep in mind, the crop here is not specific to the mini primes. Focal length is focal length. It's a property of sensor size. You will get the same angle of view or image from a 2/3" scarlet whether you are using a 25mm mini prime or a 25mm RPP or a 25mm FF35 Canon or Nikon lens...

As announced in the Nov 30th thread, it's actually a 6mm and not a 6.5mm for the widest prime. The 2/3" Scarlet sensor has a recordable area of 9.260mm x 5.184mm, based on the 16:9 resolution of 3072x1728 and a photosite size of 3um (0.003mm). When figuring AOV, we consider the horizontal sensor measurement in most situations. Diagonal does us little good unless we are shooting a square imager or relating two different frame sizes of equal proportions, which we are not...

6mm
2/3" Scarlet = 75.31°
R14K = 123.04°
APS-C = 123.42°
S35 = 128.52°
FF35 = Yeah, right... (OK, 143.13°)

As you can see, APS-C and RED One 4K are very similar in size, so they may as well be considered the same.

25mm
2/3" = 20.98°
R14K = 47.73°
S35 = 52.93°
FF35 = 71.51°

I'm coming up with a factor of 3.9X with my math, actually 3.89X is a bit more accurate. 25mm gives a 20.98° AOV on the Scarlet 2/3" and a 71.51° AOV on FF35. To get a 20.98° AOV on FF35 you would need a 97mm lens. 25mm x 3.89 = 97.25mm.

20.98° on FF35 = 97.214mm based on tan(A/2) = 36mm/2F
Where A is the AOV and F is the focal length.

Likewise, I'm coming up with 2.68X as a factor between the Scarlet sensor and S35.

Mini prime focal length equivalents to S35 and FF35 on Scarlet 2/3":
Scarlet ~ S35 ~ FF35
6mm ~ 16mm ~ 24mm
8mm ~ 21mm ~ 31mm
16mm ~ 43mm ~ 62mm
25mm ~ 67mm ~ 97mm
50mm ~ 134mm ~ 195mm

....Yes, I spent too much time on this. And David Mullen posted while I was pounding on my calculator.

 

[David Mullen ASC]

Yes, but the actual recorded area on the S35 and FF35 sensor affects FOV, and until we know what the specific size of the Monstro sensor is and the specific size of the recorded area, we can't know the exact conversion factor, not that I think it's necessary to be that exact unless you are inputting FOV info into previz software or something.

Likewise, I'm coming up with 2.68X as a factor between the Scarlet sensor and S35.

If the recorded area on the 2/3" sensor is actually 9.260mm wide, compared to the 4096 pixel recorded width of a Red One sensor, which is 22.12mm wide, that's a 2.39X conversion factor if matching horizontal view. Compared to the active Red One sensor 4520 pixels / 24.4mm, that's a 2.635X conversion factor, again if you want to match horizontal view.

But I was comparing the 9.58mm width normally quoted for 2/3" cameras versus Super-35, which is either 24.89mm (Full Aperture) or 24mm (extracted width) depending on who you talk to. That would be a 2.5X conversion factor for the 24mm figure and a 2.6X conversion factor if you use the 24.89mm figure.

 

[Jeff Kilgroe]

Yes, but the actual recorded area on the S35 and FF35 sensor affects FOV, and until we know what the specific size of the Monstro sensor is and the specific size of the recorded area, we can't know the exact conversion factor, not that I think it's necessary to be that exact unless you are inputting FOV info into previz software or something.

Yep, I was just going off of 36x24 for FF and 24.89mm wide for S35.

If the recorded area on the 2/3" sensor is actually 9.260mm wide, compared to the 4096 pixel recorded width of a Red One sensor, which is 22.12mm wide, that's a 2.39X conversion factor if matching horizontal view. Compared to the active Red One sensor 4520 pixels / 24.4mm, that's a 2.635X conversion factor, again if you want to match horizontal view.

Yep. And I wasn't trying to challenge any numbers above or anything. You made your previous post to this thread while I was still typing mine, so I didn't see it until after I had posted. To add clarification to my conversion factors, I was using my hypothetical 9.26mm width for the Scarlet 2/3" and 24.89 full aperture for S35 and 36 for FF35.

So, I got

36 / 9.26 = 3.89
24.89 / 9.26 = 2.68

RED One 4K and full sensor would respectively be
22.12 / 9.26 = 2.39
24.4 / 9.26 = 2.635 ...As you pointed out.

But you're right in that most of this is all conjecture at this point as we don't know the dimensions of future sensors with 100% certainty. We also have to accept that lens designs vary. And while we can calculate approximate AOV for a given focal length and sensor width, as I did above for the 6mm and 25mm, real world results are often slightly different due to optical distortion, lens geometry, etc..

Mysterium-X at 5K should be 27.65mm x 13.82mm
and at full sensor would be 30x15mm.

 

[Petr Dvorak]

Thanks, so it looks that just for now we can have exact calculations with non exact numbers :smiley:
So we will wait bit more ...

 

[Ace9]

If you had to choose

If you had to choose

I'm hoping to jump on the Scarlet camera but since I am only a pro hobbiest I am limited on how much I can throw at it. So the plan is to buy the Scarlet brain with mini prime mount and at best 2 lenses. The question is, In your pro opinion of most used lenses which two lenses will give me greatest latitude in run and gun filmmaking. The Gut is to go one long on short and then again the two middle focals are attractive but since I've worked only with fixed zoom lenses in the past would really like real world opinions.

THANKS GUYS!!

 

[David Mullen ASC]

Not knowing your tastes, the most practical primes would be moderately wide to medium in terms of filmmaking -- and the most natural-looking with the least distortion. Out of a 2/3" camera set that is 6mm, 8mm, 16mm, 25mm, and 50mm, I'd get the 8mm, 16mm, and 25mm. I can't really recommend less than three focal lengths though.

I've shot whole features on the Panavision 8-72mm Digital Primo Zoom on their F900's. That range covers you most of the time.

 

[Nils J. Nesse]

I'd get the 8mm and 16mm, I could happily do most of my own stuff with those.

 

[Jeff Kilgroe]

I have an affinity for wider lenses. My personal choice would be the 6 and 16 if I could choose any two. If I could choose a third, I'd have to think long and hard as to whether I would want the 8 or the 25, but would probably pick the 25. As you can see, it's somewhat personal.

In situations like this, I really think the fixed-lens model makes more sense. But then again, the interchangeable lens model does offer more options.

 

[David Mullen ASC]

It's just that a 6mm is like a 16mm in Super-35 photography, which starts to fall under the category of very wide-angle, which I find has limited applications unless you are stylistically inclined that way.

I find that even when I carry an 18mm lens on a Super-35 show, the number of times I use it on a feature is maybe only a couple of shots, and that's only for directors that like really wide-angle photography. I think you have to start getting into the 27mm range (again, in Super-35) before you stop having that wide-angle look and get into something more natural-looking in terms of perspective. I shot three seasons on different TV series where the 27mm and the 35mm were the main lenses for the majority of wide and medium shots.

So I would consider 20mm-100mm (the typical Cooke zoom range) to cover 99% of most shooting situations - again, unless there was a stylistic choice to use noticeably wide-angle shots, ala Gilliam, Kubrick, Polanski. I would find a 16mm lens (in Super-35) to be rather limiting if that were only one of two focal lengths I could have. But again, this is a very generic discussion devoid of stylistic considerations. Some projects might call for being limited to only wide-angle shots, others perhaps need long lenses. Some might only want to use the extremes and others only the lenses in the middle.

I tend to feel that the extreme ends of wide-angle and telephoto create a more stylized look, like you see in commercials or Michael Bay movies, whereas the middle focal lengths tend to not call attention to themselves and more subtly support what the actors are doing. So it partly just depends on your taste as a filmmaker.

But figuring that you won't be on sets if you are a low-budget filmmaker, there will definitely be a need for the wider-angle lenses in small rooms, hence why I think the 8mm is necessary. But I can't say for sure that the 6mm is necessary -- that one I could live without if pressed to drop something.

You also may want to consider the extra depth of field of 2/3" cameras, which may want you to avoid doing a lot of really wide-angle work if you want less depth of field.

 

[Ace9]

"It's the carpenter not the tools" argument but it's nice to own a really nice hammer :wink5: This is really great advice and this really helps in the quest to cover base's. I've gone a bit nuts laying down the foundation with a pair of nehalm mac pros, software, and gear that is making the final expedeture a bit belt busting. The hopes is camera with the complete set of mini primes but not able out the gates. Although I'm huge on Giliam, kubrik lens asthetic, I will be nowhere near that stylized. Not say copying but my emulation hopes are like Alfonso Curaon & Alejandro González Iñárritu films. Although Dave seen a few of your films, shows (most recently Jen's Body)... Excellent work!

Thanks Again All and hopefully this hobby goes pro someday!!