wide angle on APS-C sensor DSLR
 

Hello,
I am shooting video with a Canon 550D. I shoot nature and the shots I really like to experiment with are wide angle shots with the (small-mainly insects) objects near the lens. The widest angle lens I have is an 18 mm Canon. I have been looking at 12-24 mm Tokina and 10-20 mm Sigma, but the problem with these lenses is the minimum focussing distance of at least 25 cm (10 inches). I want to be able to focus at a few cm!! And I find 10 or 12 * 1,6 a bit too long. So what I am thinking of is either to use extension tubes or a wide angle adapter that attaches to the front of the lens. I guess, both will reduce the minimum focussing distance. Am I right? If so, what set up would you recommend? Or is there an other way to reach my goal?
Thanks,
Rob

The problem with extension tubes on ultra wides is that they need to really thin as you only need a tiny extension to change the focus range. To get life size image on film you need a tube of the same length as the focal length of the lens - so with a 10mm lens that would need a 10mm tube! Seems Canon do make EF mount tubes and they do do a 12mm one, so that might work, but you'll be very close to the subject.
Close-up filters for the front of the lens would almost certainly be a better idea.
I get the feeling you're after the effect of an insect large in the frame and the background behind it, with everything in focus? The way this is done in wildlife films is with a gizmo like this Sony : Optex Periscope delivers unique HD perspective : United Kingdom a borescope or probe scope. This has a relay lens and a short optic on the front and it gives massive depth of field - a famous shot was an ant on a twig with David Attenborough behind doing a piece, all in focus.
The Canon 10-22mm lens is excellent by the way.
Steve

And another thing about the Canon 10-22mm ultrawide is that its minimum focus distance is a lot less than some of the other options - Rob not close enough (I suspect) for your particular application but worth bearing in mind when you study lens specs to narrow down your choice. I can't remember off hand what it is - but it's in the 9-10 inch range from memory (Edit, just looked it up, 9.5 inches). A shallow extension tube might be the way to go then.

Thanks for your advises.
Steve, you say: close up filters will be a better idea.
Please explain. I was thinking of a wide angle adapter (or filter). Close up filters will decrease the angle in stead of getting a wider angle.

I was thinking this sort of thing Steve

I don't understand. That will decrease the angle, in stead of enlarging it.

I thought you wanted a way to get nearer? If you want an insect to be be large in the frame with a 10mm lens you'll need to be about an inch away!
Steve

Ok, I understand the confusion. I want to be able to focus nearer, but still I want the widest possible angle.
I was experimenting with an Opteka fish eye (0,20) adapter/filter in front of a 28-80 mm zoom. The zoom itself only focusses at app 35 cm. But when I attach the fisheye adapter, I can focus at 0 cm (the fish eye glass itself is app 5 cm long. So, I can hold the subject against the glass of the Opteka fish eye filter and still get a sharp image!

With this set up I have 1,6 * 28 * 0,20 = a 9 mm lens (equivalent to a 35 mm sensor)
When I zoom in to the black circle, in a way that it moves out of the frame, I have app 12/13 mm left, but gives a lot of distortion. So now I thought to buy first a decent wide angle lens (such as the ones I suggested in this post) and then a decent wide angle adapter/filter of 0,40 or 0,50. This gives me roughly 8 - 10 mm.

But there is something I do not understand. I have a Marumi 0,5 wide converter that screws just like the Opteka fish eye in front of the lens. This lens has a macro ring (with glass) attached to it (most of these wide angle filters do). If I remove the macro glass then I get a 2 times wider angle as expected, but I cannot focus. When the macro glass is attached to it I can focus but I get nothing near 2 times a wider angle (maybe 1,3).

So I fear that when I spent big money on this setup, at the end I won't be able to do what I want. Is there any wide angle adapter (of app 0,4 or 0,5) on the market through which I surely get a sharp image? And through which I can focus at very close distance (no more then a few cm). Do you guys have comparable items at home? A decent wide angle lens and a decent wide angle adapter (raynox or canon or any other better stuff). Would you be able to check this set up and share with me your findings? Even if the adapter doesn't have the good thread, still you could see what happens when you hold the items together. How near can you focus? Can you focus at all? etc.

Many thanks,
Rob

Nobody with a wide lens and a wide angle converter at home??

And Steve, yes that is exactly what I want, the subject to be an inch away from the glass. Makes great shots.

You don't want a wide lens + wide adapter, the distortion will be terrible. The wide adapter you're using isn't a good example, especially since the macro adapter sits between the camera and wide adapter.

A good close-up diopter won't decrease the angle of view. With my Tokina 11-16 + Canon 500D 77mm close-up diopter, I can focus as close as 3 inches without losing any of the width.

Thanks Kin Lau,
I WAS planning to buy the Tokina 11-16 mm. Adding the Canon 77 mm close-up filter that you mentioned, what does that do to the image quality? I mean in still photography. In video I wouldn't mind a bit of distortion or any other relatively mild artefact. But I also want to use the combination for still photography.
Rob

The Canon 500D close-up adapter is one of the best out there... so much so that many Nikon users also use it. I find the quality very good for photography.

And did you film with it or did you also take stills with that combination?

I tested the combo to make sure it works, but most of my macro shots are with much longer lenses, and unfortunately bug and butterfly session is past around here.

Kin Lau,
Many thanks for your responses. Allow me to ask you one moredetail about the combo Tokina 11-16 and the diopter lens from canon. You mentioned that you can focus as near as 3 inches. Is that with the diafragm closed down (f22)?
Thanks again,
Rob