Grey Card and 20D

[RichieHatch]

Hi

I have to shoot a Footbridge on Monday and Tuesday for my office in Ireland. I am a little worried about the weather over the two days which will probably be dull and grey/white skys. They will more than likely throw the metter on the 20D so i was thinking of using a grey card. My question is can i make one myself in PS 7 and if so how. I tried but when i fill an A4 with 18% Grey it looks very bright. Any hints....? Also have you any tips and things I should watch for...! I will be using the following:

20D+17-40f4L+50mmf1.8 and maybe 15mm fisheye...!

Mirror Lockup etc etc... of course...!

Thanks

Richie

[Bruce Watson]

I think your printer would limit the accuracy of the home made version.

They are cheap enough (around $6 US for a small one) and available at any pro oriented camera shop.

Bruce

[sdommin]

My question is can i make one myself in PS 7 and if so how.

If you can't buy a "real" grey card, you'll probably be better off by using a piece of white paper. Although different kinds of white paper use different brighteners, etc., it will most likely be closer to neutral than something you make yourself.

[RichieHatch]

Thanks Bruce.

My problem is that in my home town in Ireland there is one camera store and it hasnt any in stock. I rang a few other stores and they can all mail one to me but not before monday... hence i am trying to make one and print it. I know the whole calibration between monitor and printer is a minefield (trust me i have been to hell and back with calibration)...! But how accurate would it need to be...?

Cheers

Richie

[RichieHatch]

Hi Scott....

I am not sure I understand using white paper for exposure as surely it would give underexposed readings....? White card for white balance - yes i understand that..

Thanks

Richie

P.S. Beautiful images in your gallery

[scottbergerphoto]

I think the poster suggesting you use white was thinking about White Balance.
If you are caucasion with a medium complexion, you can take a reading off of your palm and and open up one stop, then check the histogram.
Scott

[Sailare]

As a 20D user, I find the camera pretty hard to fool. On program mode it's not likely to be far off, unless the scene is buried in snow or Volcanic ash, of course,

Since the bridge is not going anywhere and you have the time to take more than on shot, you can use the information histogram to get it right. Is it center ok? Use exposure compensation up or down as indicated and shoot again. Shoot in RAW as well. The little program that comes with the 20D does a decent job. I have found only a little adjustment is required, to get it right on.

The grey card works well, and I use it when I am waiting for a one time shot.

[RichieHatch]

Thanks for the tips guys. Yes i will deffinately shoot RAW (as i always do in tricky situations). I suppose your right... i have plenty of time to set up the shot and bracket if i need to. About reading off my hand.... well in my fair land we dont see too much of the bright yellow thing in the sky so i would say that my skin may tend towards underexposing a little....! :)

Richie

[Bruce Watson]

Yes, when I lived in Halifax, once in a while you would see crowds of people outside pointing up at a bright yellow orb in the sky and wondering what it was.................................

[DaveG]

Hi

I have to shoot a Footbridge on Monday and Tuesday for my office in Ireland. I am a little worried about the weather over the two days which will probably be dull and grey/white skys. They will more than likely throw the metter on the 20D so i was thinking of using a grey card. My question is can i make one myself in PS 7 and if so how. I tried but when i fill an A4 with 18% Grey it looks very bright. Any hints....? Also have you any tips and things I should watch for...! I will be using the following:

20D+17-40f4L+50mmf1.8 and maybe 15mm fisheye...!

Mirror Lockup etc etc... of course...!

Thanks

Richie

I think that you'll do just fine without a grey card for this shot, especially if it's a dull day.

Your only exposure problem is going to be if your meter sees lots of grey sky and tries to expose for that. That will turn the sky into a darker grey and will underexpose the bridge. Tilt your camera down to keep any sky out of the composition and then do a meter reading. This should be your exposure after you recompose, so shoot on manual. Check the exposure with a test shot and your histogram of course. The sky is going to be overexposed and there's nothing that you can do about that.

If I was doing this shot back in the old slide film days I'd use either a neutral or blue graduated density filter to add some density or colour to the sky. Now I'd just use the gradient tool in Photoshop to do the same thing, and I'd experiment until I got wht I liked.

[sdommin]

I am not sure I understand using white paper for exposure as surely it would give underexposed readings....? White card for white balance - yes i understand that..

Hi Richie,

Yes, I was referring only to the white balance question. As far as exposure goes, I rely on the "take the picture, then review it to see if it came out OK" method.

Or you could bracket your shots. That's one of the advantages of digital.

[LouDawg]

... well in my fair land we dont see too much of the bright yellow thing in the sky so i would say that my skin may tend towards underexposing a little....! :)

The palm of your hand never becomes more tan or less tan, regardless of how much sun there is. So if you use the palm plus one stop as Scott said that would probably work pretty good, just check the histogram.

[Persian-Rice]

No no no, don't use a white card for metering.
Use white for white balance.

The camera meters everything in grayscale. The medium grey is meant to act as a shade right in the middle. If you meter black, you will overexpose. If you meter white, you will underexpose.

You can meter the sky. If the sun is out, meter with the sun at your back or at the side as if you were using a polarizer. Try to avoid clouds, but if you must, they will do. Scottbergers palm reading is also a reliable one. But I am not "white" and it works for me. Mind you I ain't that dark either.

[Jonny]

As a newbie i am following this thread with much interest but i must add to some confusion.

White card / grey card for white balance i understand but not for exposure. Can some one explain what this is all about please.
Also, how big are these cards for both white balance and exposure metering?

Many thanks

[Persian-Rice]

As a newbie i am following this thread with much interest but i must add to some confusion.

White card / grey card for white balance i understand but not for exposure. Can some one explain what this is all about please.
Also, how big are these cards for both white balance and exposure metering?

Many thanks

Use a white card for what balancing............read your manual.

Use a grey card to meter for proper exposure. Fill the frame with the grey card, get an exposure reading and lock it, then shoot. This is good for situations where you cant find a good place to make a reading. ie. in snow. If you read off snow, you will underexpose everything else. if you read something like a tree in the snow, you will over expose the snow. A grey card is used to get a perfect balance, as I mentioned in my last post.

However, there are last ditch alternatives to a grey card. Your palm, the sky, and even green foliage.............etc etc

[Jonny]

[qoute]
Use a grey card to meter for proper exposure. Fill the frame with the grey card, get an exposure reading and lock it, then shoot. This is good for situations where you cant find a good place to make a reading. ie. in snow. If you read off snow, you will underexpose everything else. if you read something like a tree in the snow, you will over expose the snow. A grey card is used to get a perfect balance, as I mentioned in my last post.
[/quote]

So would you lay the card on the ground away from you (say near the centre of the scene) and then zoom onto it to take the reading. Or just hold it up in front of the camera?

[Persian-Rice]

If it is a person, hold it up against the person and bring the camera up to fill the frame, then lock. If it is a landscape, hold it up in front of the lens where the scene would be. Try to hold it as far as possible but still have it fill the frame. The point is to get a reading of the light that is hitting the scene/person on a neutral grey in order to avoid over/under exposure.

This explains in more detail............

http://home.nc.rr.com/tspadaro/The_Grey_Card.html

[scottbergerphoto]

The point is to get a reading of the light that is hitting the scene/person on a neutral grey in order to avoid over/under exposure.


Exactly!
Also see this post on using a modified zone system so you never have to use a grey card.
http://www.photography-on-the.net/forum/showthread.php?t=44320&highlight=zone+system
Scott

[RichieHatch]

Hi guys...

Thanks for the tips. The shoot went well. As expected the weather was extremely grey. I managed to get accepable shots by a combination of shooting RAW, bracketing and also using a grey grad filter. In the end the dusky/night shots turned out the best. I will post some of them on my pBase towards the end of the week when i get a chance...!

Thanks again

Richie