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Focus Issues: RedOneMX vs NikonD300, any advice?

M

Matthew Wooten

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Hello, RedUsers. I have backfocused the bejezus out of my RedOneMX and I cannot for the life of me get it to resolve as well as my Nikon D300 using the same lens.

I am locked into using a full circular fisheye lens for my work and I can't deviate from that. That lens is a Sunex SuperFisheye, 185degree fixed focus locked in at f/5.6. It's on the Red with the old Nikon dummy mount. I'm shooting at 30fps, RedCode28 at 4k 16:9 (gets me the most vertical resolution to fit the circular image). I'm quite desperate for any advice on how to resolve this image better.

If you have any conviction that upgrading to the Epic will help with this issue, I'm fine with that. (It will help me start a fire under the chairs of the money-men to get one sooner rather than later.) I can't shoot at a lower resolution or a slower frame rate, so lowering the compression is not an option. Am I missing anything else in this process that could effect the focus? I haven't been at this for very long, so any obvious things that come to mind would be appreciated.

Nikon@4288x2848, Red@4096x2304

For these comparison shots, Red is on the left, Nikon on the right. Pardon the lack of color matching. These images are unscaled.

Charts at 5 feet and 10 feet.
Charts.jpg


Thanks for any advice you folks may have to share. I appreciate it.
 
This kind of thing seems to be coming up a lot recently. Its the motion-targeted OLPF on the Red; it smooths the image more than any DSLR. The Epic will improve things for you by brute force of higher resolution / lower compressoin, but not at a pixel-for-pixel level.

iirc the MX OLPF is less rather than more agressive than the original one? May be wrong...

I'd love RED to produce an IR only assembly OLPF for special purposes like this - or maybe make available the gentler OLPF from the monochrome for general purchase.
 
Last edited:
Matthew Wooten said:
Hello, RedUsers. I have backfocused the bejezus out of my RedOneMX and I cannot for the life of me get it to resolve as well as my Nikon D300 using the same lens.

I am locked into using a full circular fisheye lens for my work and I can't deviate from that. That lens is a Sunex SuperFisheye, 185degree fixed focus locked in at f/5.6. It's on the Red with the old Nikon dummy mount. I'm shooting at 30fps, RedCode28 at 4k 16:9 (gets me the most vertical resolution to fit the circular image). I'm quite desperate for any advice on how to resolve this image better.

If you have any conviction that upgrading to the Epic will help with this issue, I'm fine with that. (It will help me start a fire under the chairs of the money-men to get one sooner rather than later.) I can't shoot at a lower resolution or a slower frame rate, so lowering the compression is not an option. Am I missing anything else in this process that could effect the focus? I haven't been at this for very long, so any obvious things that come to mind would be appreciated.

Nikon@4288x2848, Red@4096x2304

For these comparison shots, Red is on the left, Nikon on the right. Pardon the lack of color matching. These images are unscaled.

Charts at 5 feet and 10 feet.
Charts.jpg


Thanks for any advice you folks may have to share. I appreciate it.
Click to expand...

Matthew,
Loose the screws on the sides of the sunex lens then you can actually pull focus. We worked alot with those lenses and also converted them to PL. And I think even if your backfocus might be right the nikon mount might be slightly off. So if you loose the screws and preferably replace them with wing nut screws you can adjust it to best possible focus for the scene and then you should be better off. I think that you will find that this procidure also will improve your nikon panoramas...

If the above does not help I would turn to the 8mm ultra prime and shoot 4 instances, we did that for a job and had about 15k prestine panoramas in HDRx 98 fps from th epic... we did the wrapping / mapping in nuke.

hope this helps.
 
Thanks for the advice, guys. It doesn't sound like the OLPF is going to be a 'user serviceable' part. I'm a big fan of brute force, though. Time to fast track that Epic.

Bjorn, we use the same lens for timelapse and still photos with the Nikon, so I generally set the focus on the lens to the best balance of sharpness and depth of field on the Nikon, then put it on the Red and use the backfocus to get it as close as I can. Could such a uniform shift in sharpness be caused by the dummy Nikon mount? I just assumed that any ill effects caused by the mount could be compensated for with backfocus adjustment, since it is between the mount and the sensor. Again, I'm not an optical wizard, so I could be missing something very simple. If the mount could effect the image like this, would upgrading to a ProLock mount be beneficial?

We do shoot live action and documentary style stuff, so I would hesitate to wingnut the focus set screws on the lens and adjust them on the fly, but that would be possible solution. It's very hard to check the focus live through the camera with this lens, as everything is so tiny. I always have to snap a shot, then take it to the computer and blow it up to check the focus, then go back to the camera, turn the lens a bit, snap a shot, back to the computer, and on and on... Every time I have tried to set the focus live on the camera in the field it comes out pretty bad, thus the Nikon-first approach.

I'm also not too sure what you mean by 'shooting instances', especially if capturing live action. Four cameras and four lenses?

Thanks again!

MATT
 
I think that wear on the R!MX nikon mount might prevent you from ever reaching correct backfocus... it's aluminum, isnt it..
perhaps a visit to a camera house with a colimator and a flange focal depth gauge is in order.
 
If I'm able to pull a focused shot with a Nikkor 18-200mm lens, does that point to anything else in the camera, or is my lens mount still the number one culprit (other than the lens itself)?
 
Just so I understand correctly are you able to pull focus on the sunex? if so set the monitor in pixel 1:1 and make sure you got the best possible focus for the scene. If thats what you do then I guess that the difference is all camera / sensor stuff. I know also that if you render your clips using the RedRocket it will be much sharper in full 4k than if you render on the CPU's also you have to take into account that RED does not apply any post sharpening in camera.

So to get the best result out of the Red one make sure you use the best possible codec and then render your clips using the red rocket and apply unsharp mask to get the best result possible.

The distagon 8mm is to me one of the absolute sharpest 8mm so if you use that and let it overlap between 4 takes you get a full 360 your action needs to stay within the four different frames.

here is a panorama we did with epic in HDRx and the UP8mm: http://www.syndicate.se/Files/~usr/hawk/A002_C026_12049B.0000000 Panorama.mov
 
The test images in the original post are the absolute best I can get out of the Sunex. I was wondering aloud that if I could get a clean shot with a manual focus lens (non-fisheye) would that diagnose the problem and help identify the issue?

I didn't know the Rocket could effect the sharpness of the image. When I tested stills I got slightly better untreated results out of AfterEffect than RedCine. Unsharp through AE does a better job than the 'sharpness' feature in RedCineX as well, in my experience (which again isn't much).

Is another mount worth investing in, or is this as good as it gets with the Sunex lens?

That panorama does look very nice. All of our work is for full dome projection and a lot of documentary style, so multiple takes are usually not an option. How does that Distagon 8mm fill the RedOne sensor? Is the dropoff on the top and bottom edges any better or worse than the image I posted above from the Sunex?

Thanks for your time and help!
 
Yes if you can get a clean focus out of a normal lens then you know your workflow is all good except for the lens.

But just so I understand can you pull focus on the sunex or not? Or is the focus fixed? If you adjust the backfocus of the R1 and then apply the nicon mount then its very likely that the nikon mount itself does not hold the right flange distance. If so this would be easy to adjust by pulling focus on the sunex. i.e loosen the screws and twist the front of the lens until it threads into a prefect focus. when you got that right there is not more you can do. I can not see why you would get such blurry images out of it.

It is a known that when not down sampling the red rocket renders are sharper than software renderers there is no way of matching the sharpness later on in photoshop or such. The software render is what I would called "damaged" compared to the red rocket render when looked at 1:1 4k resolution.
 
I hesitate to set the focus of the Sunex based on the Red because we use that lens on the Nikon still camera, but buying a second lens would certainly be a cheaper option than, well, I guess it's my only option at this point.

I will set it up right now and monkey around with the lens.

Maybe I can roll an Rocket card into my budget with the Epic.
 
Matthew Wooten said:
I hesitate to set the focus of the Sunex based on the Red because we use that lens on the Nikon still camera, but buying a second lens would certainly be a cheaper option than, well, I guess it's my only option at this point.

I will set it up right now and monkey around with the lens.

Maybe I can roll an Rocket card into my budget with the Epic.
Click to expand...

No worries the sunex are easily adjusted back to "nikon mode" I been fiddling quite a bit with those.... check the thumb nails on this thread: http://www.reduser.net/forum/showthread.php?68976-PL-panorama-lens-system&highlight=


this panorma is shot with quiite poor focus with the sunex. still I think it looks sharper on the front of the buildings than what you got so I think you can improve it.

http://www.syndicate.se/Files/~usr/film/A027_C022_11286Q.0000000 Panorama.mov
 
Well, I adjusted a-plenty and in the end the focus looks about the same. Grrr.

Thanks for all of your help, but I think I will just have to chalk this one up to the OLPF and keep pushing for an Epic.
 
Matthew Wooten said:
Well, I adjusted a-plenty and in the end the focus looks about the same. Grrr.

Thanks for all of your help, but I think I will just have to chalk this one up to the OLPF and keep pushing for an Epic.
Click to expand...

It's the same OLPF on the Epic....

That doesn't look right at all, way too soft...
 
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