[BigMackCam]

Bit of a strange question, this one...

I recently got hold of the X-Rite ColorChecker Passport and intend to create Dual Illuminant camera profiles for Lightroom for each of my camera / lens combinations. Until I've completed that exercise, I'd like to create one Dual Illuminant profile for my K3 that I can use as a starting point for my images from that camera.

My question is this: Is there a Pentax lens - out of those I own - that is considered to be relatively colour "neutral", if that makes sense - ie. having the least effect on colour balance and with "normal" contrast (if there is such a thing)? I know how each of my lenses performs relative to each other, but I wondered if any forum members had formed opinions on which of the lenses give the most honest colour / contrast rendering in an image, and how those opinions were derived? My guess is that I could use any of my HD primes as a basis for this profile, with the understanding that I may need to tweak a little here and there when the profile is used on the other lenses. However, one thing I've noticed is that Pentax's own Embedded profile from the K3 seems to produce darker blues and reds than at least one custom profile I tried creating as an initial test, so there is probably quite a bit of difference between lenses...

The Pentax lenses I own are:

HD: DA15 F4, DA21 F3.2, DA35 F2.8 Macro, DA40 F2.8, DA70 F2.4, DA20-40 F2.8-4 WR, DA55-300 F4-5.8 WR

SMC: DA35 F2.4, A50 F1.7, M50 F1.7, DA50 F1.8, DFA100 F2.8 Macro WR, M135 F3.5, DA18-270 F3.5-6.3

Takumar: A28 F2.8

Thanks in advance

[Adam]

Bit of a strange question, this one...

I recently got hold of the X-Rite ColorChecker Passport and intend to create Dual Illuminant camera profiles for Lightroom for each of my camera / lens combinations. Until I've completed that exercise, I'd like to create one Dual Illuminant profile for my K3 that I can use as a starting point for my images from that camera.

My question is this: Is there a Pentax lens - out of those I own - that is considered to be relatively colour "neutral", if that makes sense - ie. having the least effect on colour balance and with "normal" contrast (if there is such a thing)? I know how each of my lenses performs relative to each other, but I wondered if any forum members had formed opinions on which of the lenses give the most honest colour / contrast rendering in an image, and how those opinions were derived? My guess is that I could use any of my HD primes as a basis for this profile, with the understanding that I may need to tweak a little here and there when the profile is used on the other lenses. However, one thing I've noticed is that Pentax's own Embedded profile from the K3 seems to produce darker blues and reds than at least one custom profile I tried creating as an initial test, so there is probably quite a bit of difference between lenses...

The Pentax lenses I own are:

HD: DA15 F4, DA21 F3.2, DA35 F2.8 Macro, DA40 F2.8, DA70 F2.4, DA20-40 F2.8-4 WR, DA55-300 F4-5.8 WR

SMC: DA35 F2.4, A50 F1.7, M50 F1.7, DA50 F1.8, DFA100 F2.8 Macro WR, M135 F3.5, DA18-270 F3.5-6.3

Takumar: A28 F2.8

Thanks in advance

It's mainly the body or your raw converter that determines how colors will look. Lenses can get in the way by introducing a color cast/haze (rare these days) or fooling the AWB/metering system through artifacts such as vignetting, chromatic aberration, geometric distortion, and flare.

Therefore I would use a lens that keeps those artifacts to a minimum and has a standard field of view. I can't think of a better example than the HD 35mm macro

[RDP]

I have several of the same lenses as you, and for me, I feel that it is the 100 macro that has the most "neutral" rendering. That isn't to say that it produces boring images. Quite the contrary. But it does seem to have the most natural look. I don't have the 35 macro, but from what I've seen, I suspect it might be a good choice as well.

I look forward to seeing the results of your color profiling testing.

-Robin

[Na Horuk]

Yeah, "the problem" is that most lenses these days are fairly neutral to begin with, and then things like AWB, contrast and saturation controls, shadow and highlight correction, will neutralize it even more.
I don't have any direct proof, but the modern macro lenses are probably your best choice. Portrait lenses might have a specific colour character on purpose, to render skin tones in a pleasing way. So neutralizing them too much in PP is counter-productive. On the other hand, with advanced PP software, you can make even a fairly yellow old prime appear almost clinical once you reduce CA, vignetting, fringing, WB, colour cast,..

In photography, you don't always want the colours to look clinically correct. Sometimes you want them to be warmer or more pinkish, for example. Depends on your purposes, though.

[robthebloke]

I'd probably say the DA35 f2.4 to be honest. It's got the same ghostless coatings as the FA limiteds, which to my eyes deliver the most lifelike colours (the DA limiteds are a bit punchier, with more contrast, and seem to have more saturation)

[BigMackCam]

All - thanks for your input - very useful. On balance, I'll take a stab at it with the DA35 Macro to begin with and see how I get on. We're expecting bright but overcast skies tomorrow (Thursday) here in the North East of England, which might be suitable for the 6500k (approx.) shot (not sure - I'll have to keep taking some white balance shots and see how they analyse), and my indoor lights seem to average out at around 2700k which is fine for the 2850k shot. Fingers crossed, I may be able to do the DA35 Macro profile tomorrow.

When time permits and lighting conditions are right for the 6500k shots, I intend to do the daylight shots for all the HD DA and SMC DA lenses I have at the same time, and all the indoor flourescent shots together too, so it will be interesting to see if there's any significant difference between them. I'll post results once I have them.

Thanks again...

[Digitalis]

I don't think I have ever shot with a colour neutral lens in my life. They all have colour casts of some kind - especially the lenses that use exotic glass types such as ED, SLD and Fluorite.

I shoot with cameras with a fixed manual WB value of 5000K. But frustratingly, software can interpret this differently depending on the camera used. For instance my K5IIs files are rendered in Lightroom as 5150K, Leica S2 files are rendered as 4910K, Nikon D4s as 5200K.

[BigMackCam]

I don't think I have ever shot with a colour neutral lens in my life. They all have colour casts of some kind - especially the lenses that use exotic glass types such as ED, SLD and Fluorite.

I shoot with cameras with a fixed manual WB value of 5000K. But frustratingly, software can interpret this differently depending on the camera used. For instance my K5IIs files are rendered in Lightroom as 5150K, Leica S2 files are rendered as 4910K, Nikon D4s as 5200K.

Yeah, when I was typing my question I was thinking to myself "is there such a thing as a colour neutral lens", since every lens has some impact on the light it is collecting...

Re WB interpretation, that's interesting - having said that, those examples are still fairly tightly grouped, if not 100% consistent. Does that cause you any practical issues?

[Digitalis]

Does that cause you any practical issues?

it causes a lot of problems when I have been using different cameras on the same shoot, as each image has to have the same WB value. Using AWB would make things even worse.

[RAART]

Canon had one old 50mm lens that it suits your needs but I guess it is not adaptable to Pentax. It was Canon FD-n 50mm 1.4
That was one of the best 50's I was shooting, maybe the best who knows...
One guy in Sweden can do conversion to Pentax but it is expensive.

[Lowell Goudge]

I would suggest selecting one of your lenses as a "gold standard" and simply call it neutral. Check out very camera with that lens, and establish separate camera profiles. Of course, this means that you can never sell this lens, because you're I will ne d it for every new body you get

Then having established separate camera profiles use one camera to establish the lens profiles.

Am I correct in assuming you can apply the two profiles separately?

But as others have said, WB is the issue. So when you do your ur profiles you need to consider NEVER changing WB in camera. You also need a constant light source to do all your test shots.

[Digitalis]

You also need a constant light source to do all your test shots.

Flash would be the best choice, as it is typically around 5000K - though it can vary depending on power level.

[Lowell Goudge]

Flash would be the best choice, as it is typically around 5000K - though it can vary depending on power level.

The bigger problem is using the same exact scene each time, because the overall color balance will be influenced off the light reflected from each article in the scene.

Its like shooting a white wall with the same illumination all the time.

[Digitalis]

And the light will also be influence by any light modifiers used on the flash... My old AF540FGZ had a slightly toasted fresnel from years of use - i recently had the whole unit rebuilt and the new Fresnel has changed the colour balance noticeably.

[Paul the Sunman]

The best choice for a colour-neutral lens is ... no lens. Use a pinhole.

Of course, diffraction (of which there will be plenty with a pinhole) is colour-sensitive, but that shouldn't introduce an overall cast. There's a colour pinhole photography group on flickr.