FAQ FAQ  Forum Search   Events   Register Register  Login Login

A700 color calibration results with ACR Calibrator

Page  123>
Author
Shaocaholica View Drop Down
Senior Member
Senior Member

Joined: 14 July 2006
Location: United States
Status: Offline
Posts: 1881
Post Options Post Options   Quote Shaocaholica Quote  Post ReplyReply Direct Link To This Post Topic: A700 color calibration results with ACR Calibrator
    Posted: 29 October 2007 at 06:40


I went to the local camera store and saw that they had color checker cards in stock for a decent price compared to B&H/Adorama so I picked one up to do a quick test with my A700. You can read all about the process here:

www.fors.net/chromoholics

Anyway, here are the averaged results I got from 2 different images taken in direct sunlight:

Shadow Tint: 0
Red Hue: -25
Red Saturation: +40
Green Hue: -30
Green Saturation: -20
Blue Hue: +11
Blue Saturation: -4

These settings are technically specific to MY A700 but you can try them to see if they work for your A700 as well since the variations in sensors shouldn't be that much...I hope. Just plug them into ACR or LR's calibration section under Develop settings. You can then create a preset in ACR or LR to be reused later.

I will post some real world photos tomorrow showing before and after. Reds are more affect than the other 2 colors.
 



Back to Top
nozzle View Drop Down
Senior Member
Senior Member

Joined: 28 October 2005
Status: Offline
Posts: 332
Post Options Post Options   Quote nozzle Quote  Post ReplyReply Direct Link To This Post Posted: 29 October 2007 at 09:31
Thanks shaocaholica.

That saves me money . I was already looking for calibration values to put in LR.
But i will do my own calibration anyway and will report back on my values

To mladen: I think it would be great to keep this info on a separate page, as many people may find them usefull.
Zeiss 45 f2.8 for sale
Back to Top
Turerkan View Drop Down
Emeritus group
Emeritus group
Moderator emeritus

Joined: 11 February 2006
Location: Turkey
Status: Offline
Posts: 6252
Post Options Post Options   Quote Turerkan Quote  Post ReplyReply Direct Link To This Post Posted: 29 October 2007 at 09:45
i think this deserves a place in the knowledge base.

i'd love to have the same thing with a 7d or 5d. do you have one shao?
Back to Top
kiklop View Drop Down
Admin Group
Admin Group
Dyxum owner

Joined: 14 July 2005
Country: Croatia
Location: Rovinj
Status: Offline
Posts: 10563
Post Options Post Options   Quote kiklop Quote  Post ReplyReply Direct Link To This Post Posted: 29 October 2007 at 12:53
For those interested .. just few more comments.

- calibration settings are valid for the same (or similar) WB. Unlike most other converters, ACR do use TWO internal profiles for every camera model; a daylight and tungsten WB .. and then it mixes these two to get appropriate color profile
- not all cameras are the same; mine a700 may have a bit different color response than yours
- there is a lot more technicals behind this and we even have some different scripts available. You can read more http://www.xs4all.nl/~tindeman/raw/color_reproduction.html and download another script at http://www.xs4all.nl/~tindeman/raw/acr-calibrator-l.html or another one at http://www.rags-int-inc.com/PhotoTechStuff/ColorCalibration/

Happy shooting !

Edited by Kiklop - 29 October 2007 at 12:56
Back to Top
Shaocaholica View Drop Down
Senior Member
Senior Member

Joined: 14 July 2006
Location: United States
Status: Offline
Posts: 1881
Post Options Post Options   Quote Shaocaholica Quote  Post ReplyReply Direct Link To This Post Posted: 29 October 2007 at 16:38
Oh forgot to say, these values are an average of 2 similar results taken at 5200 and 5500 degrees so its suitable for daylight only.
Back to Top
Cekari View Drop Down
Senior Member
Senior Member

Joined: 15 August 2005
Country: Sweden
Location: Sweden
Status: Offline
Posts: 7513
Post Options Post Options   Quote Cekari Quote  Post ReplyReply Direct Link To This Post Posted: 07 June 2008 at 16:53
Oops, this was an old one that I seems to have missed, but when I tested the values for bright sunshine pix in PS CS2 and LR it realy made a nice diffrence to most of my pix of that type.

So I wonder Shao, have you done any more calibrations for other conditions like in shade and cloudy etc?
would be so nice to have them as well.

Please... :-)
Images https://www.flickr.com/photos/cekari/sets/ ,

English is a funny language, seldom it spells the words like I do
 



Back to Top
AdamJ View Drop Down
Groupie
Groupie

Joined: 09 June 2008
Country: United States
Location: Naperville, IL
Status: Offline
Posts: 65
Post Options Post Options   Quote AdamJ Quote  Post ReplyReply Direct Link To This Post Posted: 09 June 2008 at 05:57
Hi,

I have found that in most cases, when the color target is 'properly lit' and an accurate exposure is made, the calibration values will not vary too much across the color temperature range. Although you can definitely find different calibration values in different lighting, you will generally have a limited range. It is this range that I use to 're-center' my calibration.

I use this re-centered calibration for a default under ANY lighting situation, and the adjust from there if I feel it is necessary (very rarely).

(Obviously if you enjoy having 3, 4, 6, 8 or more different calibrations you are more then welcome to perform the calibration at each lighting condition. If your going to go that far you should also calibrate at different temperatures because the CMOS sensor will have a different calibration depending on how cold or hot it is!   In reality, I don't feel the calibration should need to be adjusted so often, unless it is for creative purposes. Thus the whole reason for this post.)

I captured the same color checker in various lighting conditions from deep tungsten at 2700K to a cloudy 6800K. Below are the entire range of values across all lighting conditions:

Red Hue: -15 to -23
Red Sat: 20 to 38
Grn Hue: -24 to -47
Grn Sat: -20 to -34
Blu Hue: -2 to 9
Blu Sat: -5 to -17

If I take the 'average' of all the numbers in this range I come up with the following:

RH: -22
RS: 30
GH: -32
GS: -25
BH: 4
BS: -8

This calibration is what I use for my new 'default' and I find it works quite well. Obviously your milage may vary, but I just wanted to throw this out there incase people were worried they needed so many different calibrations for all kinds of different lighting conditions...


Back to Top
Cekari View Drop Down
Senior Member
Senior Member

Joined: 15 August 2005
Country: Sweden
Location: Sweden
Status: Offline
Posts: 7513
Post Options Post Options   Quote Cekari Quote  Post ReplyReply Direct Link To This Post Posted: 09 June 2008 at 09:37
Hi and welcome AdamJ.

Nice contrubution for your 1st post :-)

Thanks for your effort, will do use this and see how it works out.
Images https://www.flickr.com/photos/cekari/sets/ ,

English is a funny language, seldom it spells the words like I do
Back to Top
AdamJ View Drop Down
Groupie
Groupie

Joined: 09 June 2008
Country: United States
Location: Naperville, IL
Status: Offline
Posts: 65
Post Options Post Options   Quote AdamJ Quote  Post ReplyReply Direct Link To This Post Posted: 09 June 2008 at 16:14
Thanks Cekari!

I'm new to the A700, but not new to digital photography. I have previously used a Canon 40D, XTi, 5D and a Nikon D300.

With the new camera this place looked like the best discussion forums around for the A700.

Edited by AdamJ - 09 June 2008 at 16:38
Back to Top
kefkafloyd View Drop Down
Senior Member
Senior Member

Joined: 04 July 2006
Country: United States
Location: Massachusetts
Status: Offline
Posts: 2453
Post Options Post Options   Quote kefkafloyd Quote  Post ReplyReply Direct Link To This Post Posted: 10 June 2008 at 16:31
Those values really helped me out, cekari. I had a real issue with reds coming out "wrong" (e.g. Northwest airlines tails, Delta red, etc) and this made them snap right into place.

Fortunately Lightroom makes it easy to use different calibrations, you just have them enabled as presets. But one calibration to rule them all is also good. Thanks!
Back to Top
Cekari View Drop Down
Senior Member
Senior Member

Joined: 15 August 2005
Country: Sweden
Location: Sweden
Status: Offline
Posts: 7513
Post Options Post Options   Quote Cekari Quote  Post ReplyReply Direct Link To This Post Posted: 11 June 2008 at 15:22
Ok, have done some test on both older and newer a700 shots and I say both Shao's and Adam's work very well for me.
Prefer Shao's in very strong sunlight and Adam's in the others sort of.

Thanks for sharing those, and as kefkafloyd said they rely help out.

Images https://www.flickr.com/photos/cekari/sets/ ,

English is a funny language, seldom it spells the words like I do
Back to Top
pegelli View Drop Down
Admin Group
Admin Group
Dyxum Administrator

Joined: 02 June 2007
Country: Belgium
Location: Schilde
Status: Online
Posts: 29528
Post Options Post Options   Quote pegelli Quote  Post ReplyReply Direct Link To This Post Posted: 11 June 2008 at 15:46
Thanks to Shao and Adam for posting these for general use. They're very close to what I determined some time ago for my A700 as well, however I found that especially with red and pink flowers the subtle structure of the petals gets oversaturated and becomes one massive glob of colour (and looks ugly ). Therefore I didn't trust my own calibration and didn't use it (basically left all sliders at zero), which resulted in some colours being off but I didn't have a better way to correct. I tried again last night and obviously got the same effect again (If you keep doing what you did you will keep getting what you got   ) but except for this "blow out saturation" the other colours looked much better. So I have arbitrarily set the red saturation slider back at 0 (from ~ + 35) which still results in more accurate colours but does no longer blow out the saturation of certain red/pink areas. Obviously you can selectively reduce red saturation in shots that have this problem as well, but I choose this way to have better colours w/o the one problem I was experiencing with it.

Comments/questions welcome, because I still feel my "change" to the calibration result is very ad-hoc and empirical.
Mind the bandwidth of others, don't link pictures larger then 1024 wide or 960 pix high, see here
Back to Top
kiklop View Drop Down
Admin Group
Admin Group
Dyxum owner

Joined: 14 July 2005
Country: Croatia
Location: Rovinj
Status: Offline
Posts: 10563
Post Options Post Options   Quote kiklop Quote  Post ReplyReply Direct Link To This Post Posted: 11 June 2008 at 16:33
I can only share m own settings with the already mentioned note that this is indeed a camera specific setting any may not work for others (results are quite similar to what Shao has provided)

camera profile 4.4
Shadow Tint: 0
Red Hue: -15
Red Saturation: +35
Green Hue: -15
Green Saturation: -15
Blue Hue: +14
Blue Saturation: -11

It is worth to notice that my saved settings include other sliders as well:

exposure: -0.3
blacks: 3
brightness: +11
Contrast: -30

those changes are made to get gray patches (and overall tone distribution) as close as possible to color checker chart since i find these important when preparing my own B%W prints; these changes will however result in flat images that will most likely not suit many :)
Back to Top
k994 View Drop Down
Newbie
Newbie

Joined: 20 April 2008
Location: Hong Kong
Status: Offline
Posts: 10
Post Options Post Options   Quote k994 Quote  Post ReplyReply Direct Link To This Post Posted: 28 June 2008 at 17:49

When I type in shaocaholica's profile to lightroom, all the red and orange flowers just come alive!!!!

Thanks shaocaholica!!

Also, does anyone has a profile for tungsten light?

Back to Top
Dyxum main page >  Forum Home > Equipment forums > Camera Talk > A-mount APS-C Page  123>

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.078 seconds.

Monitor calibration strip

Dyxum.com - Home of the alpha system photographer

In memory of Cameron Hill - brettania

Feel free to contact us if needed.