# Increasing Macro magnification



## GDHLEWIS (Aug 26, 2013)

Hello all

I have a question for you all. I have currently got a Sigma 50mm 2.8 macro lens that I love. How would I be able to increase the magnification of this lens so I can go beyond the 1:1 ratio ? Would extension tubes help? I operate in complete manual when using this lens. Iv read something about below extensions (think that's what they are called) would these be of any help? 
Any information and help would be highly appreciated.

Thanks


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## ShaneF (Aug 26, 2013)

As far as i know the only options without getting a different lens are using extension tubes or a reverse mount plate.

kenko makes quality tubes that will allow you to keep control of the aperture settings  through the camera. I know there are some reverse mount plates so u can mount your lens backwards and use it as a macro lens though i have not seen them used with a 50mm .Some plates will keep the aperture intact through the camera but not sure on the auto focus but you shoot manual so it should not be an issue.
I think a full set of kenko tubes are about 200 and a reverse plate is 20 or so

Kenko International


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## GDHLEWIS (Aug 26, 2013)

thanks


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## Overread (Aug 26, 2013)

Extension tubes or macro attachment lenses (macro filters/diopters) both work in a similar manner in that they give increased magnification by reducing the minimum focusing distance of the lens. Now with a 50mm macro you'll already have a small working distance and reducing it further might make shooting with it a much more difficult task to both focus and light the shot. 

You could consider using a combination of a teleconverter and an extension tube; you need the tube because the teleconverters have protruding front elements which push into the rear of a lens; a tube thus gives you a "space" at the back of the lens to allow this as many shorter focal length lenses simply won't fit teleconverters. The teleconverter itself will increase the magnification whilst not reducing your minimum focusing distance.


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## GDHLEWIS (Aug 26, 2013)

Thanks, think I gonna have to save the pennies for something with a little more length on it, either 100 or 150 macro. Wife is gonna love me this month lol


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## GDHLEWIS (Aug 26, 2013)

Would the following work?
Iv already got a 70-300mm Sigma tele lens with one of those macro switch's on the side that doesn't really do too much. If I were to add a set of Kenko tubes on to that lens with the switch on would that make the lenses a macro lens? I cant remember the ratio on the lens but should be enough to make it a 1:1 ratio pic. My only concern with this is to use the macro switch the lens has to between 200 - 300 mm making it a rather long lens and I am afraid with the tubes on it would possibly break my camera. It's only a diddy D3200 but really don't want to mess the connections. Is there a universal tripod mount I could buy for the lens or tubes?


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## Overread (Aug 26, 2013)

Few thoughts:

1) Remember with true macro lenses the magnification is always the same - 1:1 - at its maximum. So the 150mm is only going to give you more working distance, the actual magnification won't change (although you'll likely see increased background blurring as compared to your 50mm - whilst the actual depth of field will remain the same). That said the extra working distance is great and gives you some room to add modifications to get more without losing all your working distance.

2) The rough maths for extension tubes is
(length of the extension tubes in mm - divided by - focal length of the lens) + magnification of the lens = ratio:1 

As a result the 70-300mm at 200 to 300mm which should give you around 0.5:1 magnification there without any modification, would need at least 100mm to 150mm of extension tube length just to get to the 1:1 magnification. A full set of extension tubes is normally around 65mm in length and going longer is possible, but adds more weight to the camera mount, plus loses more light within the setup because of the increased distance. 
That said with a set of extension tubes the 70-300mm shouldn't give you many problems at the functional level and shouldn't put too much pressure on the mount so long as you held the lens whilst shooting. Sadly I don't think you can easily find a tripod mount (I seem to recall once seeing an extension tube with a tripod mount on it).


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## GDHLEWIS (Aug 26, 2013)

Thanks plenty of food for thought. Will buy a set of cheap tubes to experiment with before investing in a mega buck lens


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## Overread (Aug 26, 2013)

Get tubes with the electronic contacts; they will cost more, but will retain  control over the lens. If you get the very cheap £/$5 ones you won't have any contacts and as such you won't have any lens control at all (ok for AF, but with no aperture control that becomes very hard to shoot with).

Kenko make a very affordable line of quality extension tubes.


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## GDHLEWIS (Aug 27, 2013)

I was looking at the Kenko tubes last night. I also came across a macro photography for dummies book ( I know the shame of it) so will give that a look at as well. My Sigma 70-300 has a ratio (when the macro switch is clicked) of 1:3 according to the lens documentation. Either way Ill have a play with tubes and reverse rings for the time being as the wife gave me rather evil looks when I suggested that a new lens was required lol, got a baby on the way so cant go too mad with kit. . . for now lol


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## Nervine (Aug 27, 2013)

A good setup i am currently trialling with some success is a reversed 28mm prime on extension tubes. I am not using the whole set of them. I need to actually work out the correct magnification level but I believe it is higher than 2-1 but will confirm this weekend.


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## GDHLEWIS (Aug 29, 2013)

Well the verdicts in, have decided to buy either the Sigma 150 macro or the Tamron 180 macro, but it will have to wait for a few months to get the money together as am expecting a baby in 4 months so money priority has been re-routed tho I did buy myself another SB700 with gels to stave off my camera junkie urges. Any thoughts on either of the lenses I have decided on? Going to use my Sigma 50 to practice and master on until the pennies collect enough for the big boy lens.


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## EDL (Aug 29, 2013)

One other set up is to get an adapter and turn the 50mm around backward and mount it to the front of that 70-300, then use the zooming of the 70-300 to control magnification level.

To get magnification divide the focal length of the reversed lens into the zoomed focal length.  Setting the zoom to 70mm = roughly 1.4:1 (70mm/50mm), zooming in to 300mm will give you 6:1 (300mm/50mm)

Of course, that's putting more glass between the subject and the sensor, so common consensus is you lose some IQ, but looking at shots made with similar set ups shows some pretty damn good results, especially if the lenses are good quality.

You'll have figure out a way to set the aperture on the reversed lens and typically in this set up folks will use older, manual lenses with an aperture ring, or use tape to hold the aperture control arm in place.

Not the optimum set up, but if you already have the lenses, you're only into it for the cost of the adapter to connect the two lenses.


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