Just to add to the discussion, daylight by nature is a mixed-source light.
The direct sun rays are one color temperature, but the ambient rays are another. People often forget about the giant blue dome above our heads, a.k.a. the sky, which acts as a giant softbox. So the shadows are always blue in comparison to the direct light.
A single direct light in a studio will never achieve that kind of "daylight" quality until you bounce some blue into the shadows.
I wish the testers had built a "room" with flags/floppies with a small window to allow direct sunlight in and block the ambient blue light.
I'm in 100% agreement on all of that. Everything you just said confirms why you should rate the Helium for a higher ISO.
You shifted the DR away from the highlights on Helium and now everyone's takeaway from this test is that Helium has an objective "1.5 stops worse highlights" than Alexa, when you and I both know that's all relative due to the sliding scale that is DR.
I'm just saying that calling this a "shootout" leads the reader to think there's going to be a defined "winner." When really it's just a test for a single metric: dynamic range.
If you were going to do a full shootout, then this thing needs to be like an hour long and compare compression, color fidelity/accuracy, frame rates, resolution, ergonomics, workflow, etc. etc. etc.
Alexa will win a lot of areas, still, I'm sure. I don't need Helium to "win." I just don't agree with the methodology here.
No, not 1280 on both. 1280 on Helium, 800 on Alexa.
The Helium sensor needs less light. So don't give it so much. You're overexposing it and "pull processing" it when you rate it at 800. But conveniently not doing so on Alexa at 800.
The low-light test is flawed in the same way, this time in Helium's favor.
This isn't a matter of opinion; nothing to agree or disagree with. It's physics.
Did read the second paragraph? Did you not see the 24mm shot cropped to the same framing as the 70mm and produced nearly the EXACT SAME shot (save for depth of field)?
Point is, a Raven with a 35mm lens is gonna look like a 50mm on a full frame camera, minus depth of field. That's it. There's no perspective warping/stretching going on as a direct result of a focal length change.
So again, back to the NF article, there's no disadvantage using the Raven, or any other "crop" sensor when we're specifically talking about perspective. Yes, depth of field will be deeper. Yes, wider lenses are harder to design, so they might be slower, have barrel distortion, be softer, etc. Yes, photosites might be smaller on a smaller sensor vs a larger one so it might be noisier/less sensitive to light. There's plenty of advantages (and disadvantages) shooting on larger formats. My point is that 3D space will not change just from shooting with wider lenses.
Try this: take 5 photos of a person from different distances with the same lens. You'll get perspective shift. Now take 5 photos with 5 different focal lengths from the same distance and crop them all to the same framing. You'll get ZERO perspective change.
Or easier, just give this entire video a watch: https://www.youtube.com/watch?v=GbESqYkodmQ
Pay strict attention starting at 2:35.
I'm sorry, but you're mistaken.
Photographers use long lenses for portraits because they have to back up to get a close up. Backing up is what caused perspective to compress, NOT the focal length.
Give this blog a read:https://livcophoto.wordpress.com/2016/04/11/what-is-lens-compression-and...
"For example, shooting 24mm looks closer to a 35mm because of the crop, but the warping and space compression is still that of a 24mm."
This blog is a joke... What kind of ass-backwards DSLR filmmaker thought process is this? "Crops" aren't an issue and have never been, even since the days of 16mm.
First of all, Raven's sensor is 23.04mm wide. Only 0.76mm narrower than an Alexa (excluding open gate mode), and only 0.26mm narrower than a Sony F65.
Secondly, and more importantly, lenses have nothing to do with "space compression". It's all about subject to camera distance, nothing else. Ever wonder why a zoom is more flat/static/boring than a dolly-in? That's because a change in focal length does nothing to change the relationship of your subject to your background. Only moving the camera changes perspective.