Funny colours from a SMC-P 45-125mm


BentlyTCow

Link Posted 19/06/2010 - 01:23
Hi guys, I just got a 45-125mm and, though I haven't gotten to take many photos with it, the colours seem somewhat off.. The pinks go kind of purple and the purples go blue. I think yellow and green are ok. If I shift the hue in the 'Custom Image' menu on my K200D (currently set to 'Natural') it looks a bit more like I think it should, though I think I may have pushed it a notch too far in these.

It's a really nice lens (which I got for portraits) so I'm just wondering if the hue shift is necessary? Or are my eyes deceiving me and everything look fine?

When I received it the rear element had some small spots of fungus (I think - it looked like carpet fuzz) which wiped right off. Would that cause the colour shifts? It looks clear inside but is there anything I should do to it to keep it from coming back and spreading?

Original shots are on the left, the hue shifted shots are on the right. Again, I think I may have overdone the shifting a bit, but they seem more.. right. The yellows are definitely more natural looking on the original, however.








I think the last one is the most obvious unless I never noticed that those are actually pink and violet - which is possible!

johnriley

Link Posted 19/06/2010 - 06:28
It's not clear what these images should look like - only you know that. I would suggest they are a bit too saturated, as if the "vivid" setting had been used. "Natural" is the best place to start, followed by minimal adjustment in photoshop, as required.

Colour prints were never accurate to the original, so unless there are very critical controls digital images won't be either.

Do they look right? They are not far off, but a bit bright and over-colourful perhaps.
Best regards, John

gartmore

Link Posted 19/06/2010 - 06:33
I'm not sure what you are showing us, have the pictures on the right been adjusted to make them look normal? If so, it would be better to show picture from both lenses with the same settings. Which lens are you comparing the new one to?
Ken
“We must avoid however, snapping away, shooting quickly and without thought, overloading ourselves with unnecessary images that clutter our memory and diminish the clarity of the whole.” - Henri Cartier-Bresson -

BentlyTCow

Link Posted 19/06/2010 - 07:10
Sorry, apparently I wasn't as clear as I thought I was.

These are both from the same lens, taken with the 'Natural' setting. I'm afraid I don't have other shots to post right now, though I'll try and get some later.

Essentially, the shots on the left are straight from the camera using the 'Natural' setting and the 45-125mm lens. I thought most people would know what iris' would look like.. the terra cotta pots also.

The shots on the right are a bit closer to what I think they actually look like, though I think I've pushed the hue shift a notch too far in the 'Natural' menu setting (+4 but +3 would probably be better.

Sorry for the confusion! I'll see if I can't post some shot from another lens later.

As a side note the saturation has not been adjusted from default in the 'Natural' setting, only hue on the shots on the right.

johnriley

Link Posted 19/06/2010 - 09:10
The colour of an object depends upon the colour of the light falling upon it. For this reason I set my cameras to "Daylight" and make sure the value is also a fixed one. There is an option for the camera to fine tune "Daylight" or any other setting every time a shot is taken, but I don't use that option.

The reason for that is that I like atmosphere. Atmosphere is enhanced by colour and I want to retain the unique co0lour of a scene that attracts me. I can change this in Photoshop if I wish to, but usually retain the character of the light in a scene.

To see how light is used creatively to enhance, see any episode of Doctor Who. Colour is altered to control the mood, and very skillfully too.

I would suggest Hue is not a good way to go, but instead just adjust brightness and contrast in Photoshop (or similar) and the colour can be accepted as is. To ensure the colour is not "corrected" by AWB, switch to Daylight, or Cloudy if you prefer something warmer.
Best regards, John

flossie

Link Posted 19/06/2010 - 11:02
be aware that the in-camera idea of "Daylight" is not a fixed colour-temperature but a range. I got bitten by this early on when I got very confused on a cloudy day why two pictures taken moments apart but at a different angle looked so different. When processed in RAW with the same colour temperature value, the purple tarmac in shot two became black like the first!
Still shooting in the dark (literally and metaphorically)...

johnriley

Link Posted 19/06/2010 - 11:05
Quote:
be aware that the in-camera idea of "Daylight" is not a fixed colour-temperature but a range.

I did mention this, and you can turn it off and have a fixed value.
Best regards, John

BentlyTCow

Link Posted 19/06/2010 - 23:51
Thanks for the replies guys, I feel like a bit of an idiot, but what better way to learn

Right, here's take two. I've done some (nearly) side by side shots with my Sigma 17-70 at 70mm and f/4.5 and the Pentax at 70mm and f/4. I did them in RAW+jpeg and noticed there's some strange things going on in my camera but I'll get to those in a minute. I decided to import the raw files with the default settings but change the white balance to 'daylight' in CS3. The colour difference isn't as noticeable as they first were, so I think you're spot on with the white-balance settings causing some problems. Please excuse my poor focusing! I'm not very good at it yet.

Pentax is always first:


Sigma


Pentax


Sigma


Pentax


Sigma


Pentax


Sigma



I dunno, now that I've had a chance to look at them done in RAW I think it must have been some screwy white-balance setting because if anything I think that old Pentax has a leg up on the Sigma. The colours on the jpgs out of the camera are much more vibrant than the RAW files, even though I have it set to 'natural'. I'm not sure there's much I can do beyond lowering the saturation a bit for jpgs.

I couldn't tell if I had the daylight setting set correctly in the camera or not, which is why I decided to do the RAW files in the end. It was a good thing, too, because the 'as shot' white balance settings varies from shot to shot in Adobe Camera Raw. I'll have to see if I can find how to disable the 'range' in the manual.

If you compare my first images to these you can see what I was talking about, colour-wise, especially on the fluffy pink ones. The original above looks almost lilac in colour!

One last question mentioned in the first post:

Quote:
When I received it the rear element had some small spots of fungus (I think - it looked like carpet fuzz) which wiped right off. (...) It looks clear inside but is there anything I should do to it to keep it from coming back and spreading?

I've moved it out of its old leather case and cleaned the lens caps, but is there anything else I should do?

Thanks again everyone, I really appreciate your insightful comments!

-Duane.

johnriley

Link Posted 20/06/2010 - 00:04
As regards fungus, store the lenses in dry conditions with plenty of air circulation. Any little used lenses I have are stored on an open shelf in a dry, centrally heated room.

The colours of these look much better.

The setting you want is Custom Setting 12 WB Adjustable Range. Set it to Fixed.
Best regards, John

BentlyTCow

Link Posted 20/06/2010 - 00:23
Thanks for the speedy reply, John! I shall keep it warm and dry and dusted, then.

I'm afraid my Custom Setting 12 is about the OK button.. must not be available on the K200D. The only WB settings I see in the custom menu are for the flash and making manual adjustments to the presets. Oh well!

Thanks again!

johnriley

Link Posted 20/06/2010 - 00:37
Sorry about the custom setting - looks like it's back to checking the manual!
Best regards, John

BentlyTCow

Link Posted 20/06/2010 - 22:34
Yeah.. I didn't see anything about it, it must be a 'pro' camera setting.
Add a Comment
You must be registered or logged-in to comment.