Magic Filter/WB/Slate

The widest of my Olympus(C-70) is 38mm and I know it is not enough.

But I trust the Magic Filter and its abilities. I am also Greek and we have very clear waters and a very bright sun(almost every day)!According Alex Mustard these are the excellent conditions for the Magic Filter to work.

I think that I have followed all the instructions of using the Magic Filter but I am not satisfied till now with the color of my photos. I think that maybe I don’t take the WB correctly. Maybe the size of my white slate is wrong. The size of my slate is the same as Mike Veitch’s at his test of the Magic Filter(UWP 27/41page) , but he is using a 10.5mm lens and I use a 38mm.

So when I try to take the WB, my slate covers all the view of the lens and I believe that maybe this is wrong.

If it is wrong, could you tell me the percentage of the slate’s coverage ,when I take the WB? Mike Veitch’s slate looks like 12%-15% coverage of the view. When he wants to use another lens(e.g.105mm) ,does he change the size of his slate also?

I feel a little confused. Can you help me?

Thanks

Orecha

Hi Orecha,

A lot of white slates are fluorescent - which can cause big problems for setting the WB on a number of cameras. I would try setting the WB on a neutral area of the seabed.

Alex

This is some useful text from the new (not online yet) Magic Website:

How to White Balance with filters

The original Magic filter is designed to work with the camera’s manual white balance setting (WB) and it is important to set the WB underwater. The Auto-Magic filter is designed to work with the camera’s AUTO WB, so you don’t really need to read this section.

Before diving with a Magic Filter set the camera to Custom/Preset/Manual WB and familiarise yourself with method for calibrating it (also remember to switch back to normal WB after you have finished diving with the filter!).

Generally you need to recalibrate the WB when you change depth by more than a couple of metres. In most cases you can set the WB using the subject (usually by taking a picture of it), but ensure that the subject fills most of the frame. Open water will NOT produce a suitable white balance (being completely blue it will cause the WB to be too red!). It is also important to ensure that area you choose to white balance on is illuminated by direct sunlight.

You can also set the WB off a neutral white slate or grey card ensuring it fills most of the frame. This is useful if the subject is skittish or you are diving away from the reef out in the blue.

The underwater world is filled with many neutrally coloured objects ideal for setting WB. © PR

Once you are used to it, setting the WB is very quick and just takes a few seconds.

Calibrating the white balance is really worthwhile makes a big difference to your images in camera. To take the image below (left) I first set the WB by ensuring that the frame was filled with the winch in the foreground (right), once I had recorded this value I then recomposed and took the shot I wanted

Image taken at 10m on Giannis D (©AM)

p.s. those white tiles on the Chrisoula K were really heavy!

HI ALL,

I was on the Red Sea workshop with Alex & the rest of the gang,

I did have a problem setting my WB on shark & Yolanda even at

shallow depths what ever I tried. But once set the difference was

quiet amazing. Well now I am home & went to my local dive shop

& PADI make a White Balance slate one side WHITE one side GRAY

it even tells you how to set your camera to achieve it.

Buy the way the price is £7 to £8 GBP.

Andy

Thanks Andy

Can you give me more information about how to order that slate from Greece?

Orecha

I did have a problem setting my WB on shark & Yolanda even at shallow depths what ever I tried. But once set the difference was quiet amazing.

Hi Andy,

What was the problem you were having, and how did you overcome it?

I've generally used a "standard" white diver's slate for white balance. Basically anything that looks convincingly white or neutral gives the camera a good baseline, so that what comes up on the LCD has the best colour separation. I always shoot RAW by the way so it's just a means of making the LCD tell the most useful story.

Having said that, one other trick I did try was shooting RAW with Auto WB. Again that makes the LCD review pretty useful as the colour contrast generally gets maximised by the AWB.

Alex, is there any downside you'd see to shooting through the Auto-Magic filter on a DSLR? Is it a stronger filter than the Magic, and hence we'd lose total light? I guess we can go through all this in Cayman, but I do find it very interesting.

Martyn

HI Martyn,

I did not have a slate on me & at the time Alex had lent me

one of his magic filters. So what I did was found some patches

of white sand & tried to set WB on that, but I had great diffitculty

in currents as I opened the appiture & slow down the shutter speed

on manual. So thats why I got my self the padi photo slate.

Andy

HI Oreche,

I dont know were you live or if you read Diver, they do list

3 dive centers with padi Crete Underwater Center: www .creteunderwater.com

Divers Paradise :www. diversparadise.gr Eurodivers www.eurodivers.nu

hope this helps Andy

I am sure Andy

Thanks again

Orecha

I use the studio size (3.5" x 6" or 90mm x 150mm) version of one of these:

http://www.rawworkflow.com/products/whibal/index.html

It only took about a week to get to the remote northwest of Australia from Florida. It's a lot more expensive than the PADI photo slate but it does have a lot of extra features (white/black point patch, focus target, etc)