canon 300 f4 + extention tubes?

[Glenn.B]

I have a 300mml f4 lens and use the canon 25mm extention tube, but my question is :- can i add more tubes without looseing quality.

EG:- another 25mm tube or even get the kenco 3x tube set ( 60mm in total) and use these in various combinations with the 25mm tube?

i want to photo dragon flies and damsels without getting to close and scareing them off. ( inspired by photos in this site.)

any answers and suggestions welcome.

[PacAce]

Since the extension tubes are hollow with no optics within, you can add as many tubes as you want, within reason. The only thing you're going to lose, other than focusing to infinity, is some of the light reaching the sensor.

[cosworth]

I think the word "close" was an indicator that this person may have been looking for not an extension tube but a teleconverter.

[Glenn.B]

cosworth , no its tubes i'm looking at as i want close focusing. a TC does not do what i after. But thanks.

i just want to get about 2-4 feet away but try and fill the frame?

[cosworth]

I'm not a very skilled dragonfly shooter at all but I can't EVER get 2-4 feet from one. That's if it stays still for longer than 1.7 seconds!

[DavidEB]

I'd think you want to combine tubes and a teleconverter. Put the tubes closer to the lens and the converter closer to the camera body for maximum effect. With the whole set of 3 kenko tubes and a 1.4x tcon your field of view at close focus is about an inch, and the working distance is about 1-1/2 feet (using the 300 f4). The combination takes good photos.

two things to consider -- with a long lens and lots of tubes and tcons, and a heavy camera body, mounting, balancing, & carrying the whole thing is a bit of a challenge. Also, if you want to use a flash, mounting it on the camera's shoe the lens may cast a shadow. I put an ARCA mounting clamp on a standard stroboframe, turn it 90 degrees, and mount it to the lens foot ARCA plate, that puts the flash up front.

[PacAce]

I think the word "close" was an indicator that this person may have been looking for not an extension tube but a teleconverter.
A teleconverter, unfortunately, does not get you closer to the subject although ti does make the subject look closer becaues of the magnification. But if you want close, an extension tube is what you want. :)

[Glenn.B]

I'm not a very skilled dragonfly shooter at all but I can't EVER get 2-4 feet from one. That's if it stays still for longer than 1.7 seconds!
My problem too! :lol:





David thanks, i was planning to use my 580 flash on a wimberly bracket that i have, To move flash away from directly over the camera, like you suggested. ( if needed for fill-flash )

[cosworth]

A teleconverter, unfortunately, does not get you closer to the subject although ti does make the subject look closer...

I'm baffled by the sheer obviousness of this.

[PacAce]

I'm baffled by the sheer obviousness of this.
But it does point out the fact that an extension tube and a teleconverter behave differently although they both may (although not always) give you the same image results.

With a TC, the minimum focusing distance of your lens does not change. So, if you have a lens that can only focus to 6 feet and your subject is 5 feet away, you can't take a picture of it, even with a TC attached.

However, with the proper extension tube attached, you will be able to get that lens to focus down to 5 feet and get a shot.

[Lester Wareham]

I have used mine with the full stack of kenko tubes (68mm) with good results. This gives you are magnification range of ~0.22 to 0.58 and a working distance range of 1770 to 680mm. This is great for damselflies but a bit too much extention for the bigger dragonflies.

Although there is no glass in tubes lens aberations will increase at close focus distances. One of the advantages of macro lenses is they are corrected for close distance aberations. My expectations is the 300/4 will work well as it has quite a short minimum focus but I have no way of knowing or testing other than subject results.

Also I would expect performance with tubes to be better than with TCs which will give you magnifications of 0.336 and 0.48 for the 1.4X and 2X respectively, again no tests to support this just my view. Experience of using this combination is it can be much harder to find your subject than with just tubes. You should be able to get close enough with the 300 + tubes and reasonable field craft, many people manage with 100 and 200mm lenses aparantly.

This is an example of the above setup: (a crop of about 70% of width because I could get as close as I would like 1/125 f8 handheld IS on, so it could probably be sharper but at least the CA you might expect at close focus seems absent).
http://www.zen20934.zen.co.uk/photography/GalleryPics/Photos/Insects/Damselflys/Insects%20Banded%20Agrion%20Damselfly%20male%20032 %20copy.jpg

100% crop

[Glenn.B]

Thanks for all the replies, i think i have the answer now.

Lester , thanks, the sort of photo i'm looking for is like your first one.

all i have to do now is go out and find some subjects to photo.