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Is there a 2k mode "soft image" problem or not?

Joe G.

Joe G.

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I have seen this repeated enough times to start worrying. I need high frame rates for a particular purpose (necessitating 2k mode), but the image needs to be razor sharp.

Is there a technical issue with 2k mode not giving acceptable results? By "acceptable" I mean professional, really really fucking sharp.

Some have suggested that the lenses were the problem, and/or that the back focus was not perfect.

Is that the answer, or is there something fundamentally flawed in the 2k mode architecture?

What's the actual answer?
 
Maybe it's a problem with the sensor, but I'd wager that it's probably your lenses. Like Eren said, try using S16 lenses.
 
I recently shot a lot of footage for a local zoo, all @ 2k and we ranged from 24-100fps.
we were pushing for very tight, detail shots with racks and everything came out very very sharp, from macaw feathers to the wrinkles on the elephants eyelids to the individual whiskers on the cheetahs.
So in response i guess what i'm saying is i have yet to run into any softness @ 2k that was 'inherent' as opposed to user induced (ie: focus, motion blur, backfocus).
-c
 
back focus ?

back focus ?

mail4joeg;269765. Some have suggested that the lenses were the problem said:
By doing some testing with prime lenses, you could eliminate any backfocus issue, since there's no backfocus issue with primes, is there ?
Click to expand...
 
soft image on 2k

soft image on 2k

i put a post in the f900 thread saying that i experienced soft images using Red at 2k 16/9 with a 9.5 mm s16 lens.
and the images in that case were truly and visibly soft.

http://www.reduser.net/forum/showthread.php?p=269668#post269668

and this happened all 4 days of shooting, which were 1 week apart from each other. Every single shooting day the camera went out with backfocus checked by the rental shop, which i completely trust. ( the Red camera is mine, but they take care of it.)
shooting was at 100 fps, but we made a test at 25 and nothing changed visibly in terms of softness.
we started pulling focus with the tape, but later we abandoned it and relied on all the focus assists the camera could give us. and the images were a little better, but still soft.

i have to say that on the same shooting days we used also an optimo 24-290 mm 35mm zoom, and the image with that lens was crystal clear and way way sharper.

i have come to believe that the problems lies on the backfocus area, especially because those days was really, really hot, and maybe heat can do bad things to the lens mount.

comparing images with other digital cameras is difficult because sometimes what looks sharper is in fact too sharp, say too "electronic". Red images are really more natural and organic.

so the real true test would be comparing 2k red images to film, either 35mm or 16mm, with same lenses ad same fps, and see what comes out.

btw, is there a reliable on-field backfocus adjuster i can look after?

thanks,

alessandro.
 
yes.
i tried a 10 mm 35mm ultra prime, but images were even softer.
 
even 4k looks soft to me.. ive never touched the back focus though.. gona do it tomorrow
 
Were the lenses in question correctly collimated? Seems weird that some lenses were sharp and others not. I've seen softness around the edges of the frame with wide angle lenses on Red (not noticeable on a monitor - only noticeable zoomed in with RedCine), but the same lenses looked less sharp on the frame edges on a lens projector too (it takes a good lens, well maintained, to be equally as sharp at the extremities as the centre). Is the softness in your case all-over or just round the edges? If it's all-over it could be as simple as bad back focus - if it's out slightly it'll look more obvious on a wider lens. How does your rental house perform back focus checks? I'm sure they're highly reliable like you say, but checking the back focus on the Red isn't quite like any other camera they might be used to. One big thing to consider is that when you check the back focus and everything seems spot on and then you tighten the allen keys on the mount the back focus can go out slightly - I didn't believe this till recently when I was checking someone else's camera. I never encountered that problem on our own camera. I don't know if there's a difference between older model mounts and newer ones??
 
Hi Guys!
BTW, ive seen the Mummy3 at this week in theatre,and then download trailer in HD1080 format.
The picture is Super Sharp! - i love it!
And they used Cooke Prime Lenses
 
Yeah, we have been doing a bunch of shooting in 2K 120 frames per second. We had an Arri ultra prime 85mm lens. Everything has been fantastic. Ultra sharp and simply amazing.

The one thing to remember, is go with the relative shutter mode as many have mentioned. It will serve you well. Motion blur needs to be delt with when shooting in an overcranked mode. The Relative shutter mode will help. If you have movement, I would seriously suggest not leaving it at 48th of a second. Relative will select a new shutter speed for you as you adjust the frames per second. It is a really cool function of the camera!

I was also told by a fantastic color correction facility in LA that you might even consider going with a higher shutter speed then what the relative mode may give you at your selected frames per second. They said don't worry about motion blur- if you have the light, get that shutter bumped up high and let the color correction facility deal with adding motion blur down the road. This will keep things extra sharp for you.

Hope this helps!
 
back focus issue with primes

back focus issue with primes

deadmike said:
yes, backfocus is an issue with primes as well.
Click to expand...

Well, how come, if you focus "by eye" in the evf, of course....? What looks in focus will be as much in focus as it seems, I had thought...Can you explain ?
 
2K is 1/4th the resolution of 4K... this is not rocket science.

Jim
 
Jannard said:
2K is 1/4th the resolution of 4K... this is not rocket science.

Jim
Click to expand...

This would explain 2k producing a softer result than 4k. But it seems that some are experiencing softer images than others at 2k. This I guess could be narrowed down to either lens issues or (dare I say it) sensor inconsistencies.
 
Blue said:
This would explain 2k producing a softer result than 4k. But it seems that some are experiencing softer images than others at 2k. This I guess could be narrowed down to either lens issues or (dare I say it) sensor inconsistencies.
Click to expand...

You can rule sensor inconsistencies out... lenses, back-focus, bad focus or operator error. But not sensor inconsistencies. There are none at 4K... so there are none at 2K.

Jim
 
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