Gray card substitution?

[antonio_carusone]

I just recieved my Kiev Spot prism and I want to calibrate this thing and I need a gray card

to do it. Im a work right now and dont have time to run out to B&H to pick one up.

 

Is there something else I can use? I was thinking about making a page in Photoshop at 18%

gray and then printing it out but the print wont be accurate.

[dale_dickerson2]

With out a 18% gray card, I have done the following:

 

 

I use a clean large white matt surface.

 

I meter using a properly calibrated lightmeter that suface.

 

I note the reading.

 

Next I read the same surface using the meter I want to calibrate.

 

I adjust the meter to match the first meter's reading.

 

I take new readings with both meters to check for any problems.

 

If your first lightmeter is currect the second meter will now be reading the same.

[antonio_carusone]

So it will be acurate without a gray card? I have a nice big white wall right next to me and

we have bright fluorescent lights. It should work right?

[charles_stobbs3]

I have read that a page of newspaper classified ads, a grey asphalt street (not newly paved) or a lawn may be used. I have never actually tried any of these.

[m_.]

your palm is about 18% grey which you will carry anywhere you go.

[titrisol]

You can check calibratio using ANY color or shade of gray as long as you are consistant.

 

Use a white wall or a green wall, and measure it with a calibrated meter (handlheld is best), then measure with your kiev meter.... voila!

If you take a picture, it should be 18% gray :)

[cameron_ertman]

Use the "sunny 16" rule to calibrate your meter. Find an open area of blue sky in a northern direction, on a sunny day at approx. 12:00 p.m. Point your meter at an approx. 60-70 degree angle above the northern horizon (due north) and have your aperature set at 16. At this point, the shutter speed number that is indicated should match the ASA you have your meter set at (e.g. if your ASA number is 100, then your meter should be indicating a shutter speed of 1/100 @ f/16). If the numbers don't match, simply more your ASA dial until they do and you will have a correctly calibrated meter.

[steven_muncy]

I calibrate new meters to old with a number of items. Palm of hand, handkerchief, camera

bag, notebook paper, shaded side of car. Use the things you will most likely have with you.

[jim_jensen]

"your palm is about 18% grey"

 

Your palm is a very convenient substitution, true. It tends to be

about one stop lighter than 18%, though. So be sure to

compensate for that.

[peter_white2]

To calibrate your palm, place it in direct sunlight and take a meter reading. Set the aperture to f:16 and see how far from the film's asa is the shutter speed indicated by the meter. If your palm reflects 18%, the shutter speed should be the same as the asa. If it's different, just factor in that difference whenever you need to use your palm as a grey card.

[lex_jenkins]

Medium green construction paper is very close. So is grass. Meter at an angle for most reliable results.

[wayne_crider4]

You don't have a handheld meter or another camera with a meter?

[tito sobrinho]

"your palm is about 18% gray"

 

Hmm, 18% reflectance is Zone V. The palm is 36% or Zone VI one stop lighter than V, and the hand should be receiving the same light as the subject.

Read the palm and turn the meter dial to Zone VI i.e. open up one stop.

 

The most accurate Gray Card (18%) is the one from Kodak but I don't know if they are still available for purchase.

[harry_zet]

i found out that a newspaper (without pictures) is exactly the same brightness than a 18% card

[jeffrey_abelson]

" I was thinking about making a page in Photoshop at 18% gray and then printing it out but the print wont be accurate."

 

If your paper is profiled and you use the info box in photoshop, the print should be very close.

[john_wintheiser]

I have found that a concrete sidewalk in shade is pretty close.