New snapper

Having spent the last 20 years as a photographer above water, I am about to venture below the UK's waters with a camera for the first time. I'm in the process of buying an Ikelite housing for my EOS20D & Sigma 12~24mm. Anyone got any useful tips or pointers?

Yea, the sigma 12-24 wont fit in an ikelite housing.......

It is too large diameter.

You need Canon 10-22 lens.

Thanks, the supplier of the housing has my lens to see if he can modify it to fit by removing the hood and barrel grips. If this doesn't work I'm probably going for the sigma 15mm FE option. How does that compare with 10 or 12mm for angle of view on a conventional lens?

The 15 is wider than 12 and much much shaper(especially underwater). It is similar to 12 in vertical angle of view but much wider horizontally.

The advantage of a lens such as 12-24 is the ability to zoom. Even if you were able to cut your 12-24 down to a size that would fit in the housing, there is no way you would be able to zoom. So ther isnt much point.

Thanks for the advice, after reading yours and many other posts on the forum I think that the 15mm will be my best option. When I've had a bit of ptactise with a fixed lens I may add the 10~22mm sometime in the future.

SB

You will be very happy with the 15mm fisheye. I too own the 12-24 Sigma and it's a decent lens, but you will do much better with one of the "digital optimized" zoom lenses made for your canon 1.6x crop sized sensor. I use a 1DmkII so this lens is the only wide zoom option for me.

Sincerely,

James Wiseman

Thanks for the advice. I used the 15mm FE this weekend and was impressed with the lens but not my ability to get everything I pointed it at in focus!!! I hope that this was because of the cropping of the lens's field of view caused by the 1.6X chip and the fact that it was in water. I used manual focus and was surprised at how critical this had to be on such a lens even at f5.6.

The cameras white balance was left on auto as it is above water and I used fill flash for foreground objects. On the whole the colour rendition was close to what I expected but at the top of the frame where the water was several stops more light on the shallow dives, I was getting a pink cast which I'm having trouble dealing with in photoshop.

Any ideas???

Regards,

SB

Hi Simon,

It sounds you'll need a photo editing or RAW development program (you did shoot RAW format, right?) to fine-tune the white balance.

With digital cameras, the auto WB often works well for macro, but almost NEVER works well for wide angle.

PS - why did you shoot the lens in manual focus? It's auto-focus works fine for me.

Cheers

James

Hi James,

I do shoot RAW but have to get to grips with the colour management software as I have never had to do too much with above water shots in the past. I shot manual focus simply because I didn't want to have to change the focus point underwater (I already had too much to think about on the first few dives)!

If Auto WB doesn't work for wide angle shots, what does?

Cheers,

Simon

There is no good way to get WB to come out of the camera perfect. The cameras were not programmed with diving in mind.

Shoot raw and adjust WB in the raw converter. Either use the dropper tool and click on a neutrally coloured object in the picture or use the slider and adjust it untill it looks right to your eye.

No need to change focus point. Just allways use the center focus point. If you want to focus on something not in the center, focus and then recompose. (still much faster the MF)

Thanks, I'll give these a go this evening. Just looked at the cameras manual again and I see that you can use the 'custom white balance' facility. Not sure if this can be done u/w but I'll consider this option aswell.

You can try custom white ballance, but you must set it very frequently because the light conditions are constantly changing underwater with depth strobe to subject distance.