close up

[mikeg]

Hello,

I've got a sigma 70-200 f/2.8 lens on my D30 and I want to make some close ups. I want to shoot fishes/invertebrates in a saltwater aquarium somtimes less than 1 cm (0.4in.)
The problem is that this lens has a minimum focusing distance of 180 cm (70in.)
Are there any close up lenses for sigma as Canon has for its range ?
Or maybe if someone has another idea...


MikeG

[Roger_Cavanagh]

Mike,

I can think of two easy options to use with your current lens:

- extension tubes
- close-up filter

E-tubes are a fancy hollow tube (no optics) that fit between the camera and the lens. They increase magnification as a proportion of the focal length of the lenses and the total length of e-tube. They come in different sizes and can be combined, for example, I have a set of 3 from Jessops in the UK - 13, 21, 31 mm - with them all stacked that's 65mm, which at an FL of 70 would be almost 1x magnification. Focusing distance becomes much smaller with e-tubes and you will lose some light - 2 stops at 1x.

The close-up filter screws on the front of the lens where a normal filter goes. Canon makes the 250D and 500D (and a not so good 500). They come in different filter sizes. The number is actually the maximum focusing distance in mm. The 250D is recommended for FL 50-135 and the 500D for 70-300.

At 200mm, you would get a max magnification of 0.57 with either filter. The longer the FL, the greater the magnification; I have the 500D, which gives 0.91x at the long end on my 100-400. You could use a 1.4x or 2x extender on your Sigma and increase the magnification of the c-up filter.

C/up filters will not lose any light, and are a bit more expensive than e-tubes (unless you buy the Canon ones :) ).

You can use them both together to get a combined effect. If you want only one thing, my recommendation would be get the 500D. I use it much more than the e-tubes and it's much less hassle.

Regards,

[mikeg]

Thanks Roger for your explanations.

Would a Canon 500D close up lens fit on my SIGMA (77mm diameter) ?

[gmitchel]

The Canon close-up filters are great. They are available in 77mm. Expect to pay around $150 each, and they are heavy.

I doubt the close-up lenses will get you close enough to to the glass for aquarium shots. You really do need to get right up close to the glass to avoid reflections, especially if you want to use flash.

The 50mm and 100mm will get you to within about 8 inches. You can use an extension tube to increase magnification and reduce the working distance with macro lenses.

Will you be shooting in a studio? Or are you going to do it in a public aquarium? If you shoot aquariums in a non-public setting, you can use a dark blanket and gaffer's tape to drap you and the aquarium you're shooting to keep out stray reflections.

Be aware, the problem with problem with aquarium shots is getting sufficient depth of field. Macro shots have a fraction of an inch for depth of field, and fish do swim about.

To increase depth of field beyond a razor's width, you need to use a very small aperture. If you use the flash for fill-in, you can wind up with blurry subjects unless you are very careful.

Macro lenses, like the 180mm "L" lens give you an extra stop for depth of field (f/32 on the 180mm), as well as much sharper optics than any 70-200mm zoom ever manufactured. Closeup lenses and extension tubes are a mediocre substitute for a good macro lens.

BTW, you can pick up the 50mm EF macro for not much more than you will pay for 500D or 250D closeup filters in 77mm size. Less than the pair of closeup filters will cost you.

Have fun!

Mitch

[mikeg]

Mitch,

The aquarium I'm gonna shoot is mine. Everytime I wanna shoot the tank I close the curtains. But I've just ordered a circ. pol. filter.
I just had a loolk on a 50 mm macro lens but it's more expensive than those tubes or close up lenses and you get only 50mm FL instead of those 200 mm from a 70-200 f/2.8 lens.

[gmitchel]

You can get 1:1 with the 50mm macro and the extender built for it.

The magnification for the 500D is 1:2 with a Canon 70-200mm. Plus, the zoom is less sharp to begin with, and you're going to lose sharpness and add edge distortion.

Your choice, just realize, 200mm + close-up filter is not equal to 50mm macro in any respect.

You can also use the 50mm as a standard 50mm lens for portraits, landscapes, etc. The optics on macro lenses are among the best corrected available.

One closeup filter -- the 500D alone -- is approx. $135. You can buy the macro lens for $100 more.

Mitch