5K and RPPs

[Jon MIchael Puntervold]

Are all the RPP's covering the 5k area of the MX sensor?

Best,
Jon M.

 

[Nick Wernham]

All of them apart from the 18mm which does vignette a bit. I believe that the 18-85mm zoom vignettes a bit at its widest focal lengths too.

 

[Jon MIchael Puntervold]

Okay, thank you, according to this thread, the 18 mm is fine at 5k, at least some of them according to some users:
http://www.reduser.net/forum/showthread.php?78335-18MM-RPP-and-5K&p=1039622#post1039622

hmm...

 

[Mike 'Fireman' Ross]

All of them apart from the 18mm which does vignette a bit. I believe that the 18-85mm zoom vignettes a bit at its widest focal lengths too.

The 18-85 certainly does; thank the Goddess for reframing in post! I'd like to put a hard stop latch on that lens so it can't happen by accident.

Mike

 

[Nick Wernham]

Okay, thank you, according to this thread, the 18 mm is fine at 5k, at least some of them according to some users:
http://www.reduser.net/forum/showthread.php?78335-18MM-RPP-and-5K&p=1039622#post1039622

hmm...

I own the set apart from the 300mm and, at least on my Scarlet, the 18mm vignettes at 5k.

[EDIT]Also, based on the size of each lens in the set's image circle and the size of the sensor crop on the Dragon (which has been mentioned on these forums by someone from Red some time over the past few months) it looks like the lenses will all be fine at 5k on Dragon (the pixels on the sensor will be slightly smaller, so the 5k crop will be smaller than a 5k crop on the MX sensor). However, at 6k the 18mm, 25mm and 35mm are expected to vignette. Bear in mind though that the 5k crop of that sensor is still larger than S35 equivalent.

 

[Jon MIchael Puntervold]

I wish they made the Dragon with a 4:3 Super35 area, but also as wide as they currently plan it, formed like a cross, that would be so nice. A real Alexa killer

 

[Jon MIchael Puntervold]

We don't need to use all of the sensor at all times, real estate is good. Greed is good.

 

[Jeff Kilgroe]

The 18mm does show a tiny bit of black in the extreme corners. I've seen some examples look worse than others, mine covers quite well at 5K and I would be hesitant to actually call it a real vignette. The 17-50 RPZ shows a bit more clipping in the corners, and is still visible at 5K 2:1. V2 with the improved front hood is much better in this regard, but still doesn't quite cover 100%. The 18-85 zoom is the worst offender of the lot. It does fully cover 5KFF at 20mm and longer. Or at least that's what I seem to recall from the last time I shot with one -- I don't own that lens.

When Dragon arrives, we'll have to re-evaluate everything. The smaller pixel size will [read should] give us 5K within the standard S35 window, but we will have some 6K resolution to contend with. But until actual coverage circles, pixel dimensions and active resolutions are stated, we're just stabbing in the dark.

One thing to keep in mind when shooting 5K on the MX sensor, is that it's wider than standard S35. Many cinema lenses, especially the wider focal lengths out there, don't quite cover. Truth be told, some of them have a bit of trouble covering the width of standard S35, let alone the 27.65mm width of MX 5K....

 

[Stephen Williams]

One thing to keep in mind when shooting 5K on the MX sensor, is that it's wider than standard S35. Many cinema lenses, especially the wider focal lengths out there, don't quite cover. Truth be told, some of them have a bit of trouble covering the width of standard S35, let alone the 27.65mm width of MX 5K....

Thats because lenses were designed for Acedamy 35, S35 only became 'big' with the advent of DI's, all very recent!

 

[Jon MIchael Puntervold]

Some say the 18mm vignettes at 5k, some say it's absolutely no vignetting in the corners... are any of you who say it vignettes using matte-boxes when you did the tests?

 

[Jeff Kilgroe]

Like I said, this has come up before. Took a few minutes on google to track it down, but I posted this about a year ago... 5KFF frame grab with RPP 18mm. The beginning of the vignette is there, but very slight. I have seen others post samples as well and some show more pronounced clipping in the corners, which is weird, but it seems to happen. For all intents and purposes, I would say this lens provides "full coverage", but that's subjective. While it may show some loss in the corners, the 18mm RPP stays pretty sharp and resolves well into those corners.

 

[Dave Blackham]

Is the vignet on the 18mm independent of iris setting ie is it visable wide open and stopped down ?