Luminous Landscape Forum

Equipment & Techniques => Digital Cameras & Shooting Techniques => Topic started by: russellsnr on May 07, 2013, 03:29:56 pm

Title: Calibrate a Sekonic L758 Meter to Camera?
Post by: russellsnr on May 07, 2013, 03:29:56 pm
Hi,  I have the color-checker passport without the Grey card, just has the white balance target so how do I take an ambient light reading for Grey to set up calibration for the meter to camera?
I do have another make of a Grey target would there be a great difference if I used that or should I put the meter as close as possible to the Grey patch on the front of the CCP?
Thanks in advance
Russ
Title: Re: Calibrate a Sekonic L758 Meter to Camera?
Post by: MarkL on May 10, 2013, 08:16:30 am
The easier way to calibrate the meter I have found is to look at DxO's test for your camera and check what the true ISO is. The adjust the meter accordingly.

Eg. My D700s true iso was 160 so I dialed in -0.3EV into my sekonic meter.
Title: Re: Calibrate a Sekonic L758 Meter to Camera?
Post by: Jack Hogan on May 14, 2013, 01:54:12 am
Hi Russ,

I am not sure what you mean by not having the gray card: all passports have a gray balance target - one only need to know what it's reflectance is.  In fact for your purposes it would be helpful to know the reflectance of every neutral patch within it.  And you can find it on page 5 of this very helpful technical evaluation. (http://www.rmimaging.com/information/ColorChecker_Passport_Technical_Report.pdf)

Cheers,
Jack
Title: Re: Calibrate a Sekonic L758 Meter to Camera?
Post by: russellsnr on May 14, 2013, 03:05:19 am
Hi Russ,

I am not sure what you mean by not having the gray card: all passports have a gray balance target - one only need to know what it's reflectance is.  In fact for your purposes it would be helpful to know the reflectance of every neutral patch within it.  And you can find it on page 5 of this very helpful technical evaluation. (http://www.rmimaging.com/information/ColorChecker_Passport_Technical_Report.pdf)

Cheers,
Jack

Hi, Thanks for the reply and the link. There is a new CCP out and on the place where you used to sign your name and put a date there is now a large grey patch next to the white balance target however I have done a little research and seems that the small grey patch 4th in from the left on the bottom row is what may be used to get an accurate reading with the spot meter on the L-758.
when you wish to calibrate meter and camera together.
Thank you again
Russ
Title: Re: Calibrate a Sekonic L758 Meter to Camera?
Post by: Ellis Vener on May 14, 2013, 03:39:42 pm
Do you mean this? http://www.sekonic.com/products/all/accessories/sekonic-exposure-target-ii.aspx
Title: Re: Calibrate a Sekonic L758 Meter to Camera?
Post by: russellsnr on May 15, 2013, 01:58:29 am
Hi, Thanks for reply Ellis.
The new card can be seen here http://www.photographyblog.com/news/special_edition_x-rite-sekonic_colorchecker_passport_and_sekonic_grey_balan/

You can see that there are now two grey/white cards now where you used to be able to put your name and replacement date there is now a grey patch.
Russ
Title: Re: Calibrate a Sekonic L758 Meter to Camera?
Post by: Ellis Vener on May 21, 2013, 11:30:20 am
Hi, Thanks for reply Ellis.
The new card can be seen here http://www.photographyblog.com/news/special_edition_x-rite-sekonic_colorchecker_passport_and_sekonic_grey_balan/

You can see that there are now two grey/white cards now where you used to be able to put your name and replacement date there is now a grey patch.
Russ
Fascinating.
Title: Re: Calibrate a Sekonic L758 Meter to Camera?
Post by: rpsphoto on May 21, 2013, 03:49:59 pm
Hi,  I have the color-checker passport without the Grey card, just has the white balance target so how do I take an ambient light reading for Grey to set up calibration for the meter to camera?
I do have another make of a Grey target would there be a great difference if I used that or should I put the meter as close as possible to the Grey patch on the front of the CCP?
Thanks in advance
Russ

Go on the Sekonic site. I think they have a video and will certainly have some info about this. Also, Joe Brady just did a Webinar on this about 3 weeks ago. Look for that on the Sekonic site as well.