100mm Macro f/2.8 and macro filters?

[skifly]

I have the Canon 100mm 2.8 macro lens and I was wondering what would happen if I bought one of those macro lens filters and used it with my macro lens. Would I be able to get even closer and make tiny things bigger? Is there any loss of image quality or screwing with the DOF?

[steven]

Yes, Yes, Depends on the quality of the filter and it's strength, DOF will be different.

A filter basically magnifies the image before it reaches your lens.
There are different kinds of filter out there as well, single and double lens filters, the later being more expensive but also giving a high quality image.

[psk4363]

I'm with Steve with this one. You will get closer, things will appear larger, DOF is narrowed even more, but any loss of quality will depend on the filter you use. The Canon 250D and 500D are superb and using them you will be hard pressed to notice any image degradation - they are a double element system and superior to the Canon 250 and 500 single element ones.

I've recently found a very useful (but fairly basic) book pulished by Canon USA in their Canon Workshop Series called 'Close-Up And Macro Photography' (Canon code no. 9-01700 $17.95- no ISBN though!). It covers the use of all sorts of Canon kit in producing close-up and macro images. It may be fairly hard to get hold of - if you're having difficulty you could try David Leung (Canon Pro Dealer) here in the UK (what he doesn't stock or can't get hold of re Canon gear isn't worth having) on:-

David Leung, 34 Goodmayes Rd, Ilford, IG3 9UN, UK Tel: 020 8599 6657 Fax: 020 8590 0293. ...
1AE Tel: 020 7837 5649 Fax: 020 7833 4882 Email: sales@theflashcentre.co.uk.

Hope this helps,
Barry

[pierrot]

David Leung, 34 Goodmayes Rd, Ilford, IG3 9UN, UK
:D Funny that a photo gear supplier lives in Ilford, uh? :D

[DaveG]

I have the Canon 100mm 2.8 macro lens and I was wondering what would happen if I bought one of those macro lens filters and used it with my macro lens. Would I be able to get even closer and make tiny things bigger? Is there any loss of image quality or screwing with the DOF?

I'm a huge believer in using UV filters for protection on all of my lenses EXCEPT on a macro lens.

It's not that a UV filter - or any other filter - is the problem. The problem is that the front element of the macro lens is recessed, and there's a large space between that element and any filter that you mount in front of it. When things like dust or a hair are close enough to the lens - or your eye - you see through them. There is enough separation between lens and filter that dust on the filter will be in semi focus and will be visible in you photographs.

An example of this would be crud on eyeglasses. As long as the glasses are close to your eye, the dirt is invisible. When you move the glasses away from your eye the dirt comes into focus or at least semi focus. Bug splatters on car windshields are another example. In a regular car you can get away with a lot of crud on the windshield, you just don't "see it", you see through it. But some mini-vans have a long sloping windshield set for design reasons a long way from the driver's position. Dirt on windshield of these vehicles have been a big problem as the driver is distracted by it, never has a "clean" windshield, and doesn't know why.

The same thing happens with a macro lens. The focus point is a short distance from the front element to begin with. The filter is 30% (or whatever) closer to that focus point distance. In order to get as much of the subject is focus as I can I'm going to use a small aperture. Then the dirt on the filter is going be even more visible.

I'd be very careful with a closeup filter for this kind of work. If you do use one make sure it's as dust free as you can make it.

[steven]

Hello Dave . . . . . :)

skifly is talking macro filters not UV.
Reading the posts might make this clearer.

[DaveG]

I said "It's not that a UV filter - or any other filter - is the problem. The problem is that the front element of the macro lens is recessed ...".

I thought that I was clear that ANY filter would have dust problem when used with the 100mm macro lens, INCLUDING the close-up filter. However for your clarity I change that statement to read, "It's not that a UV, Polarizer, skylight, close-up, colour correction, graduated, neutral density, or any other filter I can think of is a problem. The problem is that the front element of the macro lens is recessed ...".

Didn't it occur to you that a specific filter, including a close-up filter, doesn't make any difference to the dust issue?

[steven]

I don't understand about the front element being more recessed than other lenses.
I have both the 100mm Cannon and the 180mm Sigma macro lens and the front element is the same distance from the filter mounts as my other lenses and my 50mm is ore recessed than any of the lenses.
So I can see where the increased image size would be more adverly affected by dust/dirt on lens or filter I don't think front element being recessed on macro is an issue.

P.S. not that I want to continue the other line (sorry) but what sent me off was your first line "I'm a huge believer in using UV filters for protection on all of my lenses EXCEPT on a macro lens." which I couldn't relate to the toppic.

[RianFlynn]

yes yes. on that 100mm macro the glass comes right up to the front. Its not recessed like the 50 or 60mm

Rian

[RianFlynn]

I really brought this one back from the dead. haha

[chris clements]

skifly is talking macro filters not UV.
Reading the posts might make this clearer.

I made the same mistake on first reading ; we have a language problem here. This side of the Big Pond we'd call these close-up lenses, not filters. What are they "filtering" ?

[FIREWALLROB]

will the 500D fit (and work) on normal lenses, like the 100-400. Or are they suited to macro lenses only ?

[Lester Wareham]

You could use a close-up lens on a macro lens but I would think it would be better to add some extension tubes or a TC.

Close-up lenses are basically diopter lenses to reduce the focus distance, they work rather like reading glasses. They are well known for introducing chromatic aberation although the better ones control this to a degree.

I have the 100mm f2.8 Macro also and use it sometimes with my EF 2X TC, I have to mount a small extension tube (12 or 13mm) between the lens for compatibilty reasons, you probably don't need to do that with a 3rd party TC like a Kenko.

This setup gives me 2:1 magnification at the same working distance as I get 1:1 with normally. The camera does not see the 2 stops loss of the TC like this so you have to remember that and not stop down too far. I normally shoot with this lens at f16 (sometimes f22) to maximise depth of field without getting too much sharpness loss through diffraction. So with the 2X fitted that would be a set stop of f8 to f11, any more and you get soft shots.