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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Day 1 of RED tests... unsharp?

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cinemano

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Hello..

We did some tests with the red.. and i'll be frank.. when i open a frame 1:1 actual size on the LAptop screen its doesn't look razor sharp to me.. in fact it looks soft.. We used a Nikon mount, with a 85mm Nikon Zeiss Lens.. I looked at the quicktime F file (largest one) on actual size.. looks soft. something im doing wrong? Cos it looks better when shrunk to 2k as if the red was a 2k blown up to 4k .. lol .. Shall i try with a PL lens?
Perhaps its the 28 Redcode? Is it just the nature of the beast? Digital cinema is softer to make it look like film? Thats what i didnt like about my old hvx..
 
cinemano said:
Hello..

We did some tests with the red.. and i'll be frank.. when i open a frame 1:1 actual size on the LAptop screen its doesn't look razor sharp to me.. in fact it looks soft.. We used a Nikon mount, with a 85mm Nikon Zeiss Lens.. I looked at the quicktime F file (largest one) on actual size.. looks soft. something im doing wrong? Cos it looks better when shrunk to 2k as if the red was a 2k blown up to 4k .. lol .. Shall i try with a PL lens?
Perhaps its the 28 Redcode? Is it just the nature of the beast? Digital cinema is softer to make it look like film? Thats what i didnt like about my old hvx..
Click to expand...

How did you check the flange depth/back focus of the camera with the Nikon mount on?
 
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Actually Im thinking perhaps i squeezed onto the little electric wire inside the plate when i screwed in the Nikon Mount.. Its so hard to make the cable stay inside that thin trench-looking gap to put the nikon mount over without going over the cable. Perhaps my mount isnt totally flat on??
 
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I used the Focus assist and all.. looked pretty sharp.. Gona do more tests.. will try a 22 F-Stop sunny shot to see if it gets better
 
Mark is right on. RED is sharp as heck. But only if fed an image that's in focus.

In order to do that you need to make sure your lens is at *exactly* the right distance from the sensor. You do this by adjusting flange depth / back focus of the mount.

This is not a per-lens thing. This is about getting the lens mount at precisely the right distance. It is quite a sensitive thing! Easiest way to do this is to put on a sharp wide-angle lens..

This is a normal thing for cine cameras. Once you have it right you'll know. Just check it once in a while from then on.

cinemano said:
Actually Im thinking perhaps i squeezed onto the little electric wire inside the plate when i screwed in the Nikon Mount.. Its so hard to make the cable stay inside that thin trench-looking gap to put the nikon mount over without going over the cable. Perhaps my mount isnt totally flat on??
Click to expand...

Whoah, be careful. Don't squeeze / mangle / mutilate / short out the /i wire!

Bruce Allen
www.boacinema.com
 
cinemano said:
I used the Focus assist and all.. looked pretty sharp.. Gona do more tests.. will try a 22 F-Stop sunny shot to see if it gets better
Click to expand...

Stopping down to f/22 won't necessarily yield additional sharpness, due to diffraction. You may want to stop it down to f/5.6 or 8, tops for best results.

My 2¢ worth...
 
RED camera test

RED camera test

Another test is to open the .R3D file in RED Alert! and export a 4K TIFF file.

If that is "sharp" then the question shifts over to your QuickTime Player settings - or whatever you are using to look at this on.

Final point, RED images have no "sharpness" added to them prior to recording - unlike other video cameras. So if your lack of "sharpness" is subtle, that may be just that - so add some....
 
If you are focusing by eye and not by a tape then even if the lens mount was a little off you still can acheive perfect focus. Sharpness on the Red One is quite different than sharpness on an HVX. Jim has suggested appliying a little unsharp mask in after effects to get the Red One images to the sharpness piont we prefer. Red One does no in camera sharpening so you are not only getting a flat low contrast image before color correction,but you are also getting a very highly detailed but slightly soft looking picture. 35mm film transfers even to HD use expensive real time image enhancers because film is a lot like the Red One, a highly detailed but slightly soft low contrast image. Also, if you are shooting a subject with low detail and low contrast you will really think the image is soft. In this situation I focus on a back focus chart placed next to my subject to nail the focus. And sometimes I change the lighting to get more contrast, harder shadows/stronger backlight.
 
You'll find the QT files to be very soft, well I do.
So much so that they are just for Offline only.

RED doesn't do any sharping in camera and you need to add sharping in post to your taste.

Use REDCine or RedAlert for this and render out QT or DPX for the ONLINE.

Down-converting from 4k to SD is problematic as you end up with Jaggies and Aliasing. I've been recommended to use the QT files to down-convert in FCP which makes sense as they are already soft.
This tip hasn't been possible until Build 16 as QT never supported 16:9.

I'm still unsure if RED isn't a 2:1 only camera as 16:9 is problematic.
 
Things that go wrong:
1. Mount not put on properly.
2. Back focus off (which is why we made ours easy to check and adjust.
3. Looking at sharpness in a QT proxy. Make a 4K tiff from RED Alert! or REDCINE to see exactly where you are.
4. Missed focus (this should probably be closer to #1)
5. Soft lens (usually last on the list) but can happen if an older film lens is shot wide open.
6. Shooting wide. Apparent resolution can drop off significantly with wide lenses.

Am I missing something?

RED footage should be painfully sharp. If not, you are likely doing something wrong.

Jim
 
It seems to me that occasionally people are using an old Nikon lens that has been through god knows what and perhaps even jerry-rigged onto a camera and are somewhat surprised when it fails to perform like a fifteen grand primo that has been properly collimated etc. I don't wish to be unkind but it strikes me that back focus seems to be the prime issue in this case plus the potential for an old stills lens to go out is huge.
 
one other simple thing you can check is the high quality checkbox in the QuickTime preferences is turned on. Just something you can check before trouble shooting the camera.
 
the mount could be off. I am doing full tests today with my camera- between having to be sent back to RED for repairs shortly after i got it, it being lost by Fedex, etc, and being pretty damn busy since I did get it back in working order I haven't run the thing though its paces until today.
while I did not notice it immediately, when I taped it out it was coming out a little shy of witness marks on the one lens I have that has clearly defined witness marks. long story short- my camera body was out.
good news- their adjustable PL mount system gets kudos from me- a relatively large movement of the mount results in small depth changes. if anyone has done back focus on a video camera, you know what I am talking about. Also those used to shimming lenses also know what a relief it is not to take the whole thing apart to fix it.

Some tips for checking your lens/camera body
1) measure defined distance from focal plane to target. measure it 3 times, after you have framed it up and balanced the camera. Siemens focus target is best, but a dollar bill will work in a pinch. mess up this measurement and you will not be testing anything.
2) Ideally use a known lens with very clearly defined witness marks. even better is having multiple lenses, one as wide as you can get.
3) turn on Edge Highlight in Color in the Eyepiece submenu of Video (Also may want to turn camera to 2K so you are naturally looking at an enlarged image.) zoom lens in all the way. also use the Image zoom function.
4) focus by eye. compare to witness marks. record some. Zoom out as wide as possible. record some. Do again, only set lens to what distance is "supposed to be." Check in redcine and use zoom feature to check focus.
5) if you have other lenses, try them too. If all lenses come up short or long- problem is in PL mount on camera. If one lens is acting different than the others- the lens needs work.
6)Once you have a lens you trust, and a confirmed distance, set distance on lens to measured distance and use steps in step #3 but instead of focusing lens to make it sharp, lossen PL mount and adjust till it is as sharp as possible. Lock it in place.
7) do step #4 again. this time witness marks should match eye focus. also check with as wide a lens as possible. A tele lens that is out will just not match witness marks. a wide lens that is out will be all soft.
8) congratulations! You now have a collimated PL mount. Check it before any big job.

-Nate
 
wow.. i just made a tif.. its a LOT sharper than a quicktime.. quicktime just lost my respect.. VLC love ya!!
 
Id love to paste a jpeg showing them side by side but dont know how to put pics here
 
Also - to sharpen up those proxies with Quicktime, press apple-J click on the video track, click on visual settings and check High Quality. This will make the clips (if there are no lens / focus problems) sharp as anything.
 
Check under preferences if 'use high quality video setting' is marked.
 
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