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Messages - philipb

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16
Hardware / Re: Threadripper 2990WX
« on: 2018-11-27, 19:49:48 »

Yeah, that's the thing, I got a smoking deal on it. All the high-end boards are around 600 in Canada, and none went on sale for black Friday. I'm talking the zenith, the MEG etc. I got the Strix for around 300, so half that.  If the Strix and the Zenith essentially have the same power delivery then I'll likely take my chances with the Strix. If I'm reading your comments right, it's clearly inferior to a top-shelf board but will still work.

I'm not looking to hit 4.1 OC or something. If I can hit a stable 3.6-3.8 that will be more than good enough. I'm only considering Enermax or Noctua for cooling. Based on the DeBauer graph that's under 300W so hopefully will be workable with the Strix.

I mean, I have the cash for a better board, but not sure if I'll get any benefit from it. Higher OC's look like they need serious cooling and I'm not considering going that route, so a board that gets me to that 3.6-3.8 range should be fine. But then, maybe I am being optimistic.

PS. Juraj, are all the issues with the MEG cleared up? Running solid with public BIOS? Also, appreciate getting your input. Thanks.


17
Hardware / Re: Threadripper 2990WX
« on: 2018-11-26, 21:07:28 »
Am I an idiot for thinking I can build a setup based on Asus ROG Srtix 399X?

I don't know enough about power delivery, phases ect to evaluate the question.  I am hoping for a mild overclock, maybe 3.7-3.8 which seems doable without going to crazy power draw. Looking at the DeBauer OC guide for reference. The Strix has an 8pin+4pin power, while the Zenith has 8+8pin. But, apparently both have 8 power phases? Please feel free to correct me, I'm not even sure what the power phases imply exactly.

Really hoping Enermax get their shit together, would be nice to just buy a 360 from them and get decent cooling. Here in Canada all the stock is gone on Amazon, so hopefully, the old revisions have been removed and new stock will be improved. Maybe not though.

Looking forward to your thoughts...definitely starting to get anxious about this build reding through this thread.






18
Dubcat!!!

Just looking back over this thread and ran across this:

"And this is how you create the Specular and Albedo texture.
I say 100-50% here, this depends on your filter. Only the ratio matters.
Here is my Layer stack (Linear 32bit)

When you shoot cross polarization, you get two pictures.
One with 50% Albedo and one with 100% Specular and 50% Albedo"

Can you explain the 50% albedo issue? When I do X-pol I tend not to extract a spec pass and just end up making bump/spec from the Albedo. But when i X-Pol capture my Albedo i expose as close as possible to the ColorChecker values and then bring them in line 100% with curves. Do you see a problem with this? Also, what is the significance of the 32bit space here?

PS. also, as we discussed before, in terms of getting a liner/flat RAW, I have found a great free open source, raw developer...... It's called Rawtherapee. It has a flat default which does not add any toning and so is perfect for developing textures from.RAW. I would highly recommend it to anyone looking to develop their own textures. It accepts custom camera color calibration (ala adobe dng profile), and lens correction profiles. It is really fantastic and is my go-to texture-from-raw tool.



19

Just need a quick reality check here.....

At the end of the day this is really just a discussion about tonemapping, right? (excluding all the comping discussion)

Just the idea that an HDR/32 bit linear render benefits from some form of tone mapping before being passed to the Srgb display transformation?   I know it can get deeper than that, but at its essence that is what all this is essentially about, and all the hubbub from that blender guru guy?




20

Hey Dubcat, thanks for the detailed reply.

You are 100% right. Its the raw decoding that introduces the contrast I have been fighting against. I have been starting from Adobe standard camera calibration in ACR. This has not been a great starting point, I now realize.

3D LUTs  logC starting point got me thinking..... I understand that log is used to shoot 'flat' for video guys and preserve maximum dynamic range ('Flat' = 'linear'). So really what is needed is a flat starting point.

Being to cheap to purchase 3DLUT for the moment (thought it looks like the perfect tool for processing texture) I looked into a few other options. Here is what i found.

1)dcraw...your suggestion....definitely gave me a much flatter starting point. Great! In fact after setting my white and black point (243/52) all the other patches were pretty much in the right places. First time I've seen that.  Also interestingly, using dcraw i got like 30 extra pixels of resolution out of my sensor, hilarious, I guess Nikon feels these edge pixels are not fit for consumption.

Ill look into this further....but i must say that the lack of  GUI is a bit of a bummer...hey, do you remember what settings you were using by chance?

2)LOG vision camera profile for ACR. Its essentially a very flat conversion. Perhaps to flat. Also looking at the histogram its almost as though something has been clipped. If I try to stretch the black and white points to the edges of the histogram its like the data hits an invisible wall. Also i found the colors to be a little off. have to do more playing here. Maybe be an option, but may also have problems.

3) Nikon NX capture 'flat' profile......after stumbling across something about Nikon's flat profile online i decided to download their free raw developer.....Paydirt! thought this software is a horrendous piece of crap, the initial conversion using the flat profile is pretty damn good. From there I can export to tif and keep going. This gives me the best colors and results I think. This will likely be my new texture workflow.

Ill post a comparison of the three images when I get a chance..........Just wanted to follow up and share what id found.....of course 3dLUT is clearly the way to go, but for now im definitely getting a much better initial conversion. Wonder If I can convert with flat then create a color matrix profile with adobe DNG editor to apply back to the tifs in ACR....haven't tried that yet....will post back

PS. I don't know if you saw but episcura the texture site is giving a month of free pro access for each 8 textures you submit, 3 if they are tiled. Not bad. Now if only they would have a section of textures shot with Macbeth charts then that would be really amazing.

Okay, thanks again DC!


21
Oh wow....

This is fantastic information....Thanks Dubcat!

I just have one or two questions. Im trying to lock all this down in my mind, and have been reading everything I can get my hands on. I'm shooting my own textures, I have a Macbeth and have been experimenting with cross polarization. Im very happy with the results, but still may questions.

1) You use the term linearize. I have seen others use the same term in reference to texture/Albedo, but not sure we are all using it in the same way when it comes to texture processing (nothing to do with LWF or gamma). Some seem to mean just A) basically that lightroom/camera RAW is at all its default settings? Others B)  the idea of bringing the grayscale of the Macbeth chart into their proper luminance ranges, with the targeted adjustment tool?

Im mainly asking as Im curious exactly what 3d LUT does in this area? Its like a raw image processor that will do all this adjustment work for you ( in the sense of adjusting luminance rages)?


2) This bring me to the part where I'm finding very little information. The inbuilt (nikon for me) tone curve of our cameras.

Now I know this may not be important, but, I wish i could develop a DNG profile from/for my nikon that was Truly 'linear'. It seems that there is much contrast added to the .raw images somewhere in the camera image processing. I have begun to think of the process of adjusting the Macbeth grey scale patches as removing this inbuilt tone curve.

Does this make sense to anyone else or am i just imagining things? If our cameras had a truly liner/neutral response wouldn't our photos come out a lot closer to the 'linearized' (luminance adjustment) adjustments we make to our textures? I find when I'm adjusting my images to fit the proper Mcbeth luminance range that i am always making very similar adjustments, some how its an inverse S-curve. Always with a very steep dip between the first and second white patches. Am I wrong in thinking that I'm fighting the Nikon tone curve? If so is there a way to remove it more automatically without buying 3d LUT ?


Also, some other thoughts......I use a very similar aproach to you for adjusting the luminance patches in a targeted manner....however after setting my basic black and whit patch in ACR I go into photoshop and use a 1 curves adjustment set to color blending mode, then a second set to luminosity blending mode. In the first I white balance each color range with separate rgb curves, in the second I adjust the luminance...I found doing it all with a single curve adjustment was messing with my colors. Specifically because correcting for the nikon tone curve (weather or not my thinking is correct) Involves some pretty steep corrections for the second patch, and getting the luminance right meant my colors would start to go loopy.

This is of course time consuming, so if 3d LUT will take care of this work that would be great. Is that in fact what it does?

Okay guys, also full disclosure, I haven't tried corona, though I can see people are getting fantastic results. I just found my self reading on the forum as there are so many great discussions.

PS. the thread showing the curve response of all the 3ds max adjustments was brilliant.....ahhh the mysteries are unlocked....too bad it was mostly bad news...hehe




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