How does one get greater magnification than 1:1 from a lens that only focuses down to 1:1? Teleconverters? Diopters? Some combination?

The lenses I'm specifically interested in doing this with are:
Canon 100mm macro
Sigma 50mm and 150mm macro

Will the same technique work equally well with all three (and others)?

Hi Bruce,

Both teleconverters and diopters will help increase magnification. Teleconverters maintain working distance, but steal light. So an f2.8 50mm lens with a 1.4x TC becomes a 70mm f4 lens.

Diopters decrease working distance but don't steal any light. They are effective with lenses which start with a long working distance. Shorter working distance lenses like the 50mm do not benefit from the diopter as you don't have enough working distance to make a photo (the close focus is literally inside the port...lol). There are wet diopters that mount on the outside of the port and dry diopters that mount on the lens. There are achromat (multiple element) diopters which are better than the single element type because they reduce chromatic aberration (spelling???).

HTH
James

The extension tubes will allows closer focusing resulting in higher magnification, this without loss of opticall quality but the drawback is proximity, you end up being much closer so use only with longer focal lenght.

James: go back to bed, you are a newly wed and should still be trying to reproduce (or at least pretend to)

THis subject is of interest to me - I've been shooting various combinations of TCs and diopters, but I've never tried an extension uw. My understanding of extension is that the degree of magnification depends on the ratio of the extension to the native focal length. In other words, a short lens like a 60mm would get double magnification (100%)when used with a 60mm extension, but that same extension would only give 60% improvement when placed behind a 100mm. Hence, I thought that extension worked best with shorter focal lengths. Am I incorrect here? What specific combinations of lenses and extensions have you guys used? What degree of magnification have you achieved?

I've been working a little with the 2xTC on my 105mm. Never really had it on where the conditions were perfect as the magnification doesn't allow much in the way of water movement. And, I've ended up with lots of junk as well, but it's great when it works. Shot this in Florida a couple weeks ago:



Rand

Rand,

Cool!

Which 2X are you using? I haven't found many choices for Nikon AF (vis a vis AF-S) lenses.

Thanks,
Chris

(Nice shot, Rand!)

A TC question. My recollection is that Canon's 1.4x and 2x TC's only work with their L series lenses. What TC's are usable with Canon's non-L and/or more generic (e.g., Sigma) lenses?

This is the one I use:
Kenko

Kasey, the 60mm has a built in "extension" to attain 1:1 so if I remember well, somewhere around 30mm should give you the 2:1, but hey, I could be wrong on that one, any engineer want to coraborate or demolish this theory.

The way I figure the lens and a 60mm tube would give you 1:1 if the focus was left at infinity...

I assume that using an extension tube costs you some light (you're adding a small dark tunnel) - any rule of thumb as to how MUCH light you forfeit?

And if you can double the magnification with an extension tube, why would anyone use a 2X TC, which has a (significantly) higher price, and which introduces extra glass and thereby reduces photo quality to boot?!

Extensions are long and unweildy - a TC provides a more compact package

I use the Canon 100MM, if I know I am going for some really small stuff then I use my EF25II extention tube, it will let you focus to about 6-8 inches but only has a focus range of about 12, so anything past 12 inches you can't focus on.

I'm not convinced that using the 2x results in un-acceptable photo quality. Frankly, my goal is to spend enough time with this set-up to show that the photos are up to snuff. It's just the right dive trip conditions need to present themsleves. One more with the 2xTC:



Rand

Indeed there is light loss, you loose 1 stop when youre at 1:1, I remember that Canon use a cheater when displaying their F stop, it's described somewhere in the lens or camera manual, but with Nikon when your at 1:1 your display shows F:4 not F:2,8 at maximum aperture and minimum focusing. once you are at f:4 or smaller, the system maintain the f stop choosen, on the opposite side your smallest is f:45 at minimum but convert to f:32 at infinity focus. hope It make senses

On the topic of teleconverter, they do induce a quality loss, but I suspect that since we use the center part of the lens and converter, the quality loss is not as dramatic as it used to be with full frame. I for one find these converter perform better now in digital than before in 35mm. In the end whatever work for you is best for you.

Okay, that's what I have, too.

I don't think you can make this assumption for evey lens. Even though an extension has no glass to distort the image, it places the lens further away from the image plane than it is designed for. The optical quality is not guaranteed.

I've used both TC and diopters with good results. Sometimes both at the same time. The shot below was taken with the Canon 100mm with a 1.4x TC and a +2 diopter. F/6.3 which is effictively F/9 for shallow DOF.

That's a killer shot Herb. With that setup on a 1.6x crop camera, you are talking about a very small field of view!

Cheers
James

Good TCs should induce little degradation when used on macro lenses in artificial light and relatively small apertures. This is according to John Shaw's texts. Remember that TCs are designed for much more demanding situations - shooting distant subjects at wide apertures. Birders would envy the results we get shooting 2X or 3X TCs under water!

Rand, killer shot on that Christmas tree worm, absolutely love it!

I am using a lot of close up filters myself these days, was going to use the 1.4TC but they sent me the wrong one....

I like the limited DOF it gives and i think is an easy way to go, without having to worry about extra length on your lenses and ports.
Too bad Chris Bangs doesn't seem to post on here these days, he has some great examples of using all sorts of combinations as that is one of his specialties (guess he is too busy taking photos of children!!!! )

However, i do find that the filters do work with a 60mm, this is an example of 60mm with a +4. True, i had to get right on them to get this full frame but..it worked...luckily they were turned this way

In the good old days of manual focusing most macro lenses (e.g. 55/3.5, 105/4, and 200/4 Micro-Nikkors) only focused to 1:2 (half life size) so special extension tubes were sold to match to the focal lengths so as to yield 1:2 to 1:1 focusing range for some lenses. For example the Nikon PK-13 ring is 27.5mm long and was designed for the 55 whereas the PN-11 was for the 105. These two lenses also focused to 1:2 simply by racking out the lens elements, the extension tube carried this out for another increment equal to that intrinsic to the lens. When the 200 came out, it had internal focus (IF) and no extension tube came out for it. My recollection was the that the TC-300 teleconverter (TC; a.k.a. doubler) was recommended to bring the 200 to 1:1 but the PN-11 could be used too but less than 1:1 resulted. The IF enables lenses to compensate for lens aberrations induced by change in focus distance. This would be lost if an extension tube was used but would be conserved if a TC was used.

The bellows correction factor (due to loss of light by the extension) was engraved on the barrel of some MF macro lenses, two scales on some for use with and without the 1:1 tube. With the advent of TTL metering and TTL flash, the bellows correction factor was all but forgotten since the metering system took care of it. Interestingly, the 50 macro lens for the Nikonos RS has an automatic compensation so that as the lens is focused to 1:1, it opens up a tad. Therefore, f/22 remains T/22, (T-stop, not f/stop) but the DOF is that of the compensated aperture, i.e., less DOF. I criticized this 'feature' in my review of the RS that I did for the AAUS a decade or so ago. This is good for some folks, but DOF is sacrificed as a result.

The main problem of using an extension or TC UW is that one may have to use special lens gears; unless you have one of those ports that incorporates focusing and have a port extension tube that is the same length as your lens extension tube. Alternatively, you would have to do your dive at a fixed focus distance, like in the days of Nikonos (I to V) extension tubes and framers (remember them?).

BTW, I believe the EOS Canon 50 macro lens only goes to 1:2 and needs a tube to go to 1:1 like many MF focusing macros.

Tom

ps. forgot to mention that there are formulas for calculating the bellows correction factor, DOF etc. but are not to practical for UW use, one needs to know the total extension (tube plus amount due to lens focusing) and focal length and use a calculator. I recall one even includes pupillary magnification. One would need more input data.

I don't think that this shot demonstrates magnification beyond the native 60mm micro - unless those are pygmy mandarinfish

Well, in order to get them to fill that much of the frame (its full frame, no crop) i needed to be right on top of em, regular 60mm won't get you that full of a frame without the diopter (might have been a +2 as opposed to a +4...) but definitely more than just the regular 60 could do, believe me i tried on many occasions. Then i bought the 105.... much less frustrating that way, mandarins don't like it when you're port is only 3 inches away, ruins their sex drive...

I like the limited DOF it gives and i think is an easy way to go, without having to worry about extra length on your lenses and ports.
Too bad Chris Bangs doesn't seem to post on here these days, he has some great examples of using all sorts of combinations as that is one of his specialties (guess he is too busy taking photos of children!!!! )

However, i do find that the filters do work with a 60mm, this is an example of 60mm with a +4. True, i had to get right on them to get this full frame but..it worked...luckily they were turned this way

[/quote]

Very Funny Manta breath!

sorry about the long hiatus. The peak kiddy shooting season is over, now I can get back to concentrating on UW stuff.

I found that using (+) filters on the 60mm reduced my working distance too much when shooting at max reproduction. I have used such filters with the 105 mm with decent results.

For the intense macro up to 10:1 teleconverters are required, In the future I plan to put the 200 mm micro lens to use. I will experiment with the (+) filters when using that lens

Chris

Way to go Chris - we'll be interested to see the results from the 200mm. I'm assuming it's the newer AFS model ($$$$)

Cheers
James

It's awfully tough for you Nikon users to get higher magnifications...

Canon makes a lens that does 1x-5x straight out of the box...

~Matt Segal

Yes it is the AFS, I got it over 3 years ago and have yet to dive with it. may need a sherpa to carry the rig!

Chris

snake oil I think, Matt san! I notice that this "wonder" lens is not in your line-up;-)

All the best
chris

I'm but a mere student.

Snake oil, hardly - it's proven topside. The one caveat about the lens is that it is not internal focusing, that is, the lens extends as you move towards 5:1 (5x lifesize)...this complicates port selection. I'm working on getting my hands on a copy to try and figure out the logistics.

~Matt Segal

Hi Matt

Ok, I was only kidding,

I think all true macro lenses do not internally focus. at least all my nikon one don't!

due to the VERY narrow field of view a flat port that will accommodate the lens at its maximum extension will work. the drawback would be lighting the subject as the lens shortens at lower reproduction ratios.

My Aquatica uses a extension ring system which is great for extreme macro as this allow me to fine tune the port length to whatever lens combination I want to use. I generally try to have the front of the lens as close to the inner port face as possible in order to maximize the working distance.


James started a topic long ago where I went into detail. the thread deals with using teleconverters but most of it would apply to general super macro shooting.

http://wetpixel.com/forums/index.php?showtopic=3318

I have a few small galleries on another board with some high reproduction macro images as well as a shot or two the rig I used. the link is below, just scroll down until you see the macro galleries.

http://dive.scubadiving.com/members/profil...=3&dir_id=51925

all the best

chris

A few comments.

Canon's 100mm usm macro lens is a true internal focussing macro lens which does not physically alter its external dimensions between infinity and 1:1. The Canon 50mm macro lens only reproduces at half lifesize without an extender, whilst Nikon's 60mm goes right to 1:1 (a Canon 60mm FF going to 1:1 is on my wish list - I know Sigma make one but I haven't had good experiences with Sigmas so far).

Most manufacturers (used) to produce tables showing magnification of their lenses with both extension tubes and their own diopters fitted - but perhaps more importantly, they also showed the recommended magnifications for each combination - that is where the combinations produced their optimum results. I'm not sure whether they still do but no doubt this information will be somewhere on the web.

One point which has not been mentioned is exposure. Exposure increases as magnification increases. For those interested the formula is E = (1+m) x (1+m) where m is the magnification. So at 1:1 E = (1+1) x (1+1) = 2 x 2 = 4, ie 2 stops shift. Practically this simply means using powerful enough flash units! The cameras show this shift in different ways it would appear, and this is why the effective stop shown is not the one set.

Thanks Paul

learned a little about Canon today.

Thanks for the formula. My solution on stuff greater than 8:1 iwas add more narrow beam strobes and fine tune with strobe to subject distance. with film this was an expensive trial and error techneque. Digital as made it a one dive job. also having the ability to adjust ASA is a very welcome feature

Interesting lens. Thanks for posting Matt. Fill a 35mm frame with a grain of rice....hmmm.

Has anyone actually used this one underwater? The internal focusing is a non-issue for underwater use. All lenses are "internally focusing" once you add the port--sized to the maximum extension.

I have my doubts though if this would be a practical way to get beyond 1:1 underwater. AS I read it, this is basically a 60mm with a very close focus. So the problems of getting beyond 1:1 with the 60mm are the same here (think 60mm with a huge diopter). The minimum focus distance is 0.78"(5x) to 1.02"(1x). By the time you add in the port I can't imagine getting closer than 1" from the subject and lighting it is another matter. So perhaps its better just to use the 105mm/100m and get 1:1 at 12" which is a reasonable distance to light the subject and not spook it. I think if you are planning to go beyond 1:1 in a practical sense you need to start with a long focal length (via teleconverters or long lenses) then bring in the close focus with a diopter. Perhaps this is why I haven't heard of anyone here using this lens?

Opinions?

Yes, that's correct. Eric and I have both looked at this lens and rejected it because it has no working distance. It's made for scientists photographing static subjects, not nature photographers.

But it sure is cool.

Cheers
James

Extension tubes can be seen as a slide projector put further away from the wall/screen. The image circle becomes bigger but darker. You loose light with extension tubes because just a part of the bigger image circled is captured. Further more, every little error in image quality is magnified too. Extension tubes are often considered to have no influence on light and image quality because there is no optical element inside. But extension tubes strongly intervene into the optical system resulting in light loss and image quality degradation. I’ve experienced that image quality becomes more critical with internal focusing lenses and zoom lenses.

Teleconverters increase magnification but different to extension tubes you still can shoot at infinity. OK, different thing, but if you don't want to shorten working distance a teleconverter might be more interesting.

Here is a nice comparison between different Teleconverters. Kenko 1,5x looks really good:
http://www.traumflieger.de/objektivtest/te...erter_check.php

The site is in German but the pictures say a lot.

Julian

Note that Sigma has just announced two new Teleconverters:

http://www.dpreview.com/news/0510/05100501...econverters.asp

Alex

I think decent image quality far beyond 1:1 can be obtained by turning around the lens. But difficult to house and working distance is around camera’s flange focal lens. This would require a macro ring strobe and lots of port / gear modification.

The second image (uncropped) is around 6mm x 4mm in reality. Please don’t evaluate contrast and noise, I’ve tried with ISO3200.



Julian

Sigma converters work similarly to the Canon ones. They are specifically designed for long tele lenses (protruding element). I think the only Sigma macro you can use with these converters is the 180mm macro. Or you can try with an extension tube leaving enough space to mount another macro lens.

Basically the Kenko (or Tamron) converters are mechanically compatible to all lenses. And they are not bad at all.

Julian

The samples with the 2X converters are terrible
In samples I sow with the Kenko 2X its looks much better, but that was with prime lens. If I remember correctly its mentions that thus converters are best with prime lens.

yes. these are 100% crops. But still visible that all those converters harm image quality. That's why I preffered the Canon 100-400, which is a zoom, topside over the 70-200 + converter. I think the Kenko x1.4 performs better because the others are 2x converters.

Julian

Ok I am trying to wrap my head around all these different options.

Can someone tell me if I am right in the following assumptions:

1) 60mm + 2x Tele = 2:1 at same working distance as 60mm 1:1
2) 105mm + 2x Diopter = 2:1 at same working distance as above.

So depending on the length of the Teleconverter both should be able to fit in the same port ?

So which is a preferable way to go to get 2:1.

Sorry if I've got this all wrong but I find the subject quite confusing.

Is there a primer anywhere on diopters and Teles ?

Confused !

Mark, your assumptions are close but not completely accurate.

60mm + teleconverter = 120mm f/5.6
105 + diopter = ~90mm f/2.8

So the 60mm + teleconverter will have more working distance.

BUT the 105 + diopter will have larger aperature thus AF will work better and the viewfinder will be brighter making MF easier.

Which method is better is somewhat personal prefrence but I would argue that the 105mm + diopter is better.

Which diopter is required to produce 2:1 on the 105 mm? I do not use diopters very much therefore I have no clue. I would think it would have to be a +4 or better.

There are some good calculation scripts in the net (FOV, DOF, reproduction ratios, etc.), but it is not easy to calculate dioptre for 2:1 as some lens data, etc. are required.

I don't have a +4 dioptre but just placed my old Nikonos closeup lens (which is about +4,2) in front of a Canon 100mm macro.

from frame size (width) +4 was not enough to reach 2:1. pics shot with full frame sensor.

100mm macro @1:1 only:
Click to view attachment

100mm macro @1:1 + nikonos closeup lens:
Click to view attachment

Julian

here are a few shots using the 105 with a 4t diopter. Full magnification. Whatever the math says, this combo and the added combo of a TC2x can provide nice results. Like Rand says, you just have to keep trying so you can learn the systems quirks.

Joe

One more

the Canon 500D closeup adapter is much better corrected than a single element diopter (Nikon has something similar but maybe not in the selection of sizes)

i have used it topside with and without the Canon 1.4x (which requires a 12.5 extension to make it work) on the 105 macro - for prints up to 13x19 you'd have a very hard time telling either one (or both) is present

my recommendation is:
1 - Kenko TC so you have full focus range (the Kenko pro gets very good recommendations and costs almost as much as the Canon)
2 - if that doesn't get close enough, add the 500D which should still let you focus out to about 3 feet (as i recall)
3 - the Canon 2x with 12.5 extension tube is not terrible, and again you can add the 500d (if you've got the right port extension and can find a focus gear -- do not expect this combination to autofocus -- actually, the 105 doesn't autofucus for macro well in any configuration) - and i'd be suspect of the 3rd party 2x extenders

Chiming in a bit late here, but I shoot a lot with more than 1:1 using the old Nikon 105 macro in film days, and now with the Canon 100 USM macro.

Kenko teleconverters and extension tubes all work fine. A few sample images, all uncropped:

Canon 100+ 3x teleconverter + diopters to achieve approximately 5x magnification:
http://www.flickr.com/photos/tonywublog/17...57594174625480/
http://www.flickr.com/photos/tonywublog/18...57594174625480/

Canon 100 + 3x teleconverter:
http://www.flickr.com/photos/tonywublog/18...57594174625480/

Nikon 105 + 3x teleconverter:
http://www.flickr.com/photos/tonywublog/18...57594191585362/
http://www.flickr.com/photos/tonywublog/18...57594191585362/

The most difficult challenge with teleconverters is finding the appropriate port extensions and manual focus gears to permit manual focusing. Once you've got that tackled, you just need to keep your hands steady and squint really hard!!!

Wow!!! Very impressive results in the links and also in your site.
Do you find a significant decrees in quality because of the teleconvertors?