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Pentax 645Z vs Phase One IQ 250 vs Hasselblad H5D 50c

Michiel Schierbeek

Well-known member
Torger thanks a lot for this!

I downloaded neutral plus and need to try them all out some more.
For skin tones it looks a lot better. Not sure about my industrial shots were I like the blue's of the Embedded color profile a bit better.
Anyway in both cases it is better then Adobe standard.
Also the camera is very new to me so I do not have a lot of material to work with yet.
 

torger

Active member
The "blues" is a challenge, until I started working with camera profiling software I never understood how problematic the blue range specifically is.

You'll see that most bundled profiles render blues lighter than realistic, not just Adobe, Phase One does this too. My profile doesn't which makes blues a lot darker than typical for bundled profiles. The advantage of this is more accurate color, not only in the blue range but other colors too as it becomes easier to match all colors when you don't push any of them in the "wrong" direction.

One disadvantage of it is that it's harder to see tonality in darker blues (eye is less sensitive), so it may look more flat, it may also look more flat simply because the output colorspace is clipped more. So it does make sense to want less accurate blue in this case. (As a sidenote I don't exactly know how accurate the blue is in this case, the blue patch of the CC24 is one of those most sensitive to glare, so if the shot had some glare the blue is pushed down a bit more than it should.)

And then there's a technical disadvantage which is that for some cameras, like the Pentax and A7r-II, the raw blue channel is so much more sensitive than the human eye so you need to subtract a lot of blue to make the appropriate realistic lightness. What then happens is that in the extreme range, for example triggered by narrow band artificial blueish lights (such you can find in a city nightscape) so much blue is subtracted that you get on negative luminance and it clips to dead blue. With a light blue this does not need to happen.

To the next version of my software it will probably be possible to configure how you want the blues. Personally I'd still choose the "accurate" way, as for my subjects I don't get into the extreme blue range, but when shooting city nightscapes I'd make a special profile with a lighter blue. And as said you may prefer a lighter blue in any case to get better tonality in the range. Unfortunately to make a smooth profile one need to sacrifice a little accuracy/realism on the other colors too in that case. I'll see if it can be fixed with some sort of local adjustment at some point so you "can have it all", but it won't happen still for some time.

The posted profile will make more ugly clipping in the extreme blue range than is necessary though even with accurate blue lightness due to a bug in the software, so the next version will be better also in the extreme range.
 

tjv

Active member
The one thing colour element I'm struggling with with my new Credo 60 files is the blues, specifically the depth of blue in sky. In C1 – and Lightroom for that matter – the sky is rendered too light for my tastes, especially compared to Portra 160 scanned on my Imacon 949. Other than that, the colours are exceptional. I'm not experienced enough with C1 to know how to get the best of the conversions, but it's clear from Torger's comments that there is a lot going on under the hood that you can dig in to if you're that way inclined.

It's also clear that all of the above mentioned camera systems are pretty much on par, except for price and some specialist features (that may or may not make that price difference worth it.) Personally, I'm not convinced that C1 is the magic bit of software people make it out to be, but I do think the colour profiles and tone curve options C1 present make it very attractive for those that don't want to fluff around struggling to get the colour they want.
 

torger

Active member
Interesting that you're mentioning too light skies, this is actually something I've noted and disliked too. This is a common property, most profiles/cameras have that. In Adobe Lightroom / Camera Raw the reason is that their built-in curve desaturates blues quite much as a side effect. In DCamProf I've designed a new type of tone reproduction where this aspect can be more controlled.

Per default (in the neutral profile) the rolloff into the whitepoint is the same over the whole hue range, and desaturates a little slower than Adobe, so skies are a little bluer. In the neutral+ I've adjusted this to vary over the hue range. It's even a bit shorter in the cyan-blue-purple range, intended to target skies, which keeps saturation even better, and then elongated (ie the opposite) in the skin-tone range. For faces if you keep saturation close to clipping the highlights can look a bit flat, especially for high key portraits, so it's then better with a long soft rolloff into white. Skies generally don't look flatter as they are quite flat already in the first place.

I've noted that working with hues and adjusting them is usually the easy part, but much of the look sits not in hues, but for example in this rolloff property. Skintones are very sensitive to this.

Another trick DCamProf does is transitioning from a more RGB-based curve to a luminance based curve as saturation increases to very high levels. This can be seen in say red flowers where Adobe with it's RGB-HSV curve flattens out the tonality in the reds, while the transition into luminance indeed desaturates the highlights a bit more but instead separates color better. Capture One profiles, which overall are very well designed, seems to do something similar. There's much taste involved in profile design though, so there's not one single best, and as a profile is static you can't optimize it to work best in all situations.

It's super-interesting problems for an engineer like me, I like to work in this crossover between perception and technology. Unfortunately it's not much commercial potential in this type of stuff (I do this as a hobby), I think that's why we haven't seen any good commercial profile makers (except for reproduction applications), and thus camera color continues to be a hard-to-grasp mystery which photographers can't do much about, you get what you get. I don't think DCamProf with its command line interface will change that in any major way, but it's a small contribution.
 

GrahamWelland

Subscriber & Workshop Member
One thing that I've done (kudos to Jack for first pointing out years ago with IQ files) is to shift the blue cyan component a little using the C1 Pro advanced colour editor. It seems to me that most manufacturers shift blues to cyan (and hence look brighter) plus also a very nasty tendancy to make greens look more yellow/green than the blue/green that I normally see.

Set up a subtle cyan/blue advanced colour adjustment and save it as a style with C1 and you can apply it to all files during import or processing from a certain camera that exhibits the colour shifts. I've done this with my Phase One files for years. It only tkes a few points o adjustment to make files look more natural.
 

Paul2660

Well-known member
To my eyes the Phase One Blue rendering has always been a positive. I have always enjoyed the blue hues that I can get from C1 and many years ago stopped using a CL-PL on my Phase One skies. C1's color adjustment tools do make fine tuning the blue easier. I tend to shift the blue hue just a bit to the right (towards the red) then adjust the luminosity. The ability to make WB adjustments in a local adjustment are invaluable.


I agree that Phase One can take the greens to a more yellow hue and have to work on those colors more often.


Paul
 

torger

Active member
Having looked at a few Phase One profiles for various cameras in a low-level analytical fashion I can confirm that they do like the warm look (add yellow). Most profile makers add a little yellow, Adobe does it, Hasselblad does it, I do it myself in the neutral+ profile posted, but Phase One does it more than most. What's right is a matter of taste and everyone has their own.
 

torger

Active member
Some users have noted some blocky artifacts that may appear in highlights with my 645z profiles. It's some sort of software bug that needs fixing. At some point I'll post updated profiles which should work better, but it may take a while. I'm a bit choked with actual paid work now :)
 

GrahamWelland

Subscriber & Workshop Member
QP cards work fine - small, simple to use and easy to put into a scene. IIRC My Leaf or phase one P40+ came with them but I've used them before too.

My personal preference is the Color checker passport. Small, convenient and also has various white balance selectable segments for warmer/cooler white balance, plus a full color checker for profiling and also a large grey card.
 
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robmac

Well-known member
Have usually used the QP cards in the past, are ok,but as you'd likely guess, not very durable if you don't take care. Starting to migrate to the color checker.
 
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