F23: Possible minor fixed pattern noise?

Mike Krumlauf

Mike Krumlauf

Award Winning Filmmaker
I captured a test clip using my AJA Kona 3 card in my mac. It was a dual link 4:4:4 at 24fps and it seems like the image had this slight FPN banding going on in the image. Not bad to where it was very distracting but it was there. these small vertical black lines running down the image.. showed up best in white walls and light areas. Was wondering if anyone had delt with something like this and how to get rid of it? I should mention i captured the images as Prores 4444 files.. im wondering if its just the capturing? Its not concerning me (yet) like the banding issue i had on the F900 as that was very apparent, but i dont want it to get any worse. Anything in the secret service menu that can take a look at this?
 
When I have seen similar artifacts in both cameras and studio VTRs, especially as they get older, it's quite often capacitors on one or more of the PCBs drying out or even leaking.

Chris Young
 
cyvideo said:
When I have seen similar artifacts in both cameras and studio VTRs, especially as they get older, it's quite often capacitors on one or more of the PCBs drying out or even leaking.

Chris Young
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Would contact cleaner on the boards fix this issue then if its drying out? How can i determine that's whats causing it?
 
Here is an unlisted video of 2 shots i did. One was in 4:2:2 and the other is 4:4:4.. im sure YouTube is hiding it a little bit. But, to my eye, the minor issue is appearing in both 4:2:2 and 4:4:4 mode in both S Log and Rec 709 Gammas.

 
Personally, I can't tell on my monitor. Looks pretty clean. But best way to test for FPN is to underexpose heavily and then bring up in post. The lines become extremely apparent for evaluation.
 
I did what you suggested NroBro when capturing as DPX 10bit LOG RGB and it seems to be there but its so much less its not even worth looking into. Image seems clean. This again is capturing directly into my mac pro.. ill see if anything differs with the SRW1 deck once i get it working on the camera.
 
I would say try and narrow down what it could be. Have you used the Kona recently with other cameras and not had an issue?
If you've got another way of assessing the image at full resolution I'd see if it's still there, and if not it could be the Kona.
I've had issue with older capture cards before, lead free solder going brittle and all that.
That DPX video has some weird stuff going on, like some dropped frames at 5sec, not sure if relevant.
Had a look at your DPX still and saw some vertical line stuff going on when I brought put a curve on and sharpened it up.

What Chris Young mentioned about drying out capacitors is something that needs to be fixed by replacing the caps entirely.
Usually it's a problem with the bigger non-surface mount electrolytic ones, but sometimes can happen in the smaller surface mount ones.
In the unlikely event that it is the camera, ideally the capacitors in the relevant sections/boards would be checked to see if they're going out of spec or leaky or shorted or what have you.

I'd be testing all the different outputs on the camera, testing the monitor outs (with MLUT on and off, OSD on and off, etc etc), testing the SRW-1 recordings, testing outputs on the SRW-1 and so on until you can narrow it down.
Perhaps you aren't able to narrow it down.
What's the hours count on the camera?
 
Helweg was able to apply a sharpen filter and a curve to a DPX still i sent him of a 4:4:4 image and he got the issue to be seen a bit better for you guys to take a look. This would sound stupid but would a proper white shading get rid of it? Anything software based or is this internal? I've tried testing out the IF box into my mac and out the monitor outs into my mac at 4:2:2 and its still there. I dont have the right power to test via SRW1 yet so we will see. Honestly, its such a small defect, it can def be managed.. if i can cure it completely that would be a big bonus.

Gillette.jpg
 
sharing an email i sent to helweg so get your guys' thoughts. this is becoming very interesting to me....

"Okay i just thought of something.. if these lines go away when the cameras sharpening settings are on then maybe it has to do with my lens. The lens I’m using is SD so it already doesn’t have the spec to resolves the lines per millimeter that the sensor is giving it and with detail off on the camera its almost like driving semi blind.. the camera can’t show the full amount of sensor data with soft glass and no detail on inside it so I’m getting this artifacting? I wonder if this slight issue would show itself with detail off and say a digiprime on the body? It just doesn’t make sense to me why the lines go away (from what i can see) when detail is on.. if this is all true, then it safely tells me that the CCD block is fine. What do you think?"
 
I've spent the majority of my day off of work today to get down to the bottom of why this kind of noise is happening. I'm believing its how the images are getting captured into my mac. I think my Kona 3 card is fine, cables might need replacing but more importantly its the codec. I captured the same image as 3 different codecs, Avid DNX, Apple Prores 4444, and 10bit RGB LOG... all had different variants of the noise but the RGB codec it was gone completly.. problem is my mac pro was dropping frames left and right capturing the RGB 10bit quicktime file. I will have the HDCAM SR running on the camera within the next week, will be interested to see how things differ when shooting on tape.
 
why not buy $200 hyper deck or Atomos Blade? Why can't you use SRR1? It can be powered separate from the camera with 4 pin power supply.

If you look back through the archives you will see lots of examples of people messing up recorder workflow and getting strange artifacts. Very few if any posts about capacitors going bad... just something to think about before spraying your camera full of contact cleaner.

I found a world of difference between proper HD lens and SD B4 lens I owned. F23 is too good for SD lens.
 
P.S. I watched your vlog about the camera, and if you're looking for a new tripod that can handle a lot of weight and has a pretty good head for very little money then check out models from Prompter People or CAME-TV. They pop up used on eBay or B&H/etc. for $100-$200. Depending on the model, they can handle 30-40+ lbs.

Will of course not be as good as the best-of-the-best, but are hundreds if not thousands less.
 
NorBro said:
P.S. I watched your vlog about the camera, and if you're looking for a new tripod that can handle a lot of weight and has a pretty good head for very little money then check out models from Prompter People or CAME-TV. They pop up used on eBay or B&H/etc. for $100-$200. Depending on the model, they can handle 30-40+ lbs.

Will of course not be as good as the best-of-the-best, but are hundreds if not thousands less.
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Thank you so much for the tip! I will def look into them! I need to get a tripod for it asap as it looks like my job might contract me a few times this summer to tech some shows with my camera so i need all its components asap.. was planing on buying everything else when i get paid friday (that is if i have enough after rent :b)
 
it looks like my*tripod legs can support up to 110ibs so i just need to replace the head as my tripod head is good for up to 18 and i just weighed my F23 kit and it clocked in just over 35ibs.
 
Maybe start off with this one...

https://www.bhphotovideo.com/c/product/1288722-REG/arri_k2_43670_0_arrihead_2_production_tripod.html

lol, j/k. It's so expensive they don't even show you the price.

I see a used Kessler head, but don't know much about it or if you can rig it for cameras. 150lb payload though if you can, which should handle the F23 setup with ease.

Just something to maybe research if interested. (Also not sure if you have a 75mm or 100mm bowl.)

https://www.bhphotovideo.com/c/used/1105599/kessler_crane_th1001_hercules_2_0_head.html
 
Its a 100mm bowl and im trying to find something (new or used) $300 or under. As long as it can take a 35 or so pound payload im good. Dont have $$ for the best, wish i did haha
 
Ebay.

If you visit LA, craigslist is awesome for that.


There is a tripod company that rips off older Sachtler designs. I don’t know the long term reliability, but they are solid feeling. I think the company is E-image, but let me check that. Band Pro sells them, although you may have to call them, as their website may or may not have them.

Occasionally Ronford and baker stuff is very cheap. Though that is heavy stuff and better for crew style shooting than owner op.


Manfrotto N12 is on sale at BH.
 
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