90mm Tamron Macro lens question.

Thinking about getting into some macro stuff.
Right now I'm using my 18-140mm lens, which has a close focusing distance of 1.5 feet. Here is a shot I took of an orchid at a 140mm and at closest focus distance it would let me.
My question is, how much closer would I be able to get into this flower with a 90mm Tamron Macro lens?

Do you know the reproduction ratio of the lens you are using?

I found it. The 18-140mm has a ratio of .23x. If the Tamron is a true macro lens with a 1x (1:1), then you could focus in on roughly 1/4 of the image you made with the 18-140mm.

Eyelight said:

I found it. The 18-140mm has a ratio of .23x. If the Tamron is a true macro lens with a 1x (1:1), then you could focus in on roughly 1/4 of the image you made with the 18-140mm.

Click to expand...

Thanks. Are you taking into account that I shot this at 140mm not 90mm?

Focal length makes no difference when considering the reproduction ratio assuming the published .23x for the 18-140mm is at 140mm. But .23x would be the best ratio for that lens per Nikon.

Using a 23.5mm sensor (D7100) that means the close focus for the 18-140 would capture 102mm width of flower. Using a macro with 1x ratio you would capture 23.5mm of flower.

Indeed focal length is irrelevant when it comes to X-ratio. I'm using a 200mm to shoot but would have exactly the same photo would I have shot it with a 90mm. All focal length provides is more breathing room.

The image with the 18-140 is a landscape by comparison.

Seriously though, you will see fine detail of pollen etc with a macro and very fine texture on the leaf.

I remember many years ago explaining to my wife why her 90mm Tamron macro was so much better than her 70-300. One could photograph newspaper print text, the other photographed the dots that made it up.

If you're looking for justification it's a fantastic lens with the only caveat being it extends on focussing, unlike the Nikkor 105 2.8. I only bought the latter as she already had the Tamron and to be honest I'm not convinced the Nikkor is any better or perhaps not as good, although I don't use it a lot.


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Thanks everyone for the help. Seriously considering.

I cant elaborate much on what has been said already, however I got a tamron 90 this week, the AF is fairly good but not as good as sigma / nikon, however for the price difference Id still take the tamron.
I have posted some pics in the macro and spiders threads.

Blacktop, there are two Tamron 90mm currently available. The older one is less expensive and the barrel extends as you focus close. The newer one is internal focus and the barrel does not extend as you focus.

I have the Tamron 60mm macro. At the time, I preferred the 60 to the 90 with the extending barrel. Both will do 1:1, The extra focusing distance of the 90 was eaten up by the extending barrel. Had the new version been available, I probably would have gotten that, but I'm still happy with the 60. The 90 will go with you if you go FX.

If you are not already familiar, be aware of the difference between minimum focus distance vs working distance. Many macros only list minimum focus distance. That is measured from the sensor plane to subject. You need to subtract the length of the lens to get the working distance. The working distance is more meaningful since that is measured from the front of the lens to the subject. That is usually what you want to know... how far away you can be and still get 1:1. That means the image on the sensor is the same size as the real life object.

Blacktop said:

Thinking about getting into some macro stuff.
Right now I'm using my 18-140mm lens, which has a close focusing distance of 1.5 feet. Here is a shot I took of an orchid at a 140mm and at closest focus distance it would let me.
My question is, how much closer would I be able to get into this flower with a 90mm Tamron Macro lens?

View attachment 115594

Click to expand...

With Macro you will get 4 times the magnification 1:1 vs 1:0.23. That said, unless you want to print it big and see the pollen, just cropping the image from around 6000x4000 to 1500x1000 will get a pretty magnified image, and that is too big for most web postings!

Most macro lenses will give you 1:1, the difference is in working distance. In case you are shooting flowers in good light it does not matter if you have 2 inches or fifteen between the lense front element and the object. With bugs and flash it is different. The further away you are the less will the bug get spooked and the better will the flash illuminate. So for flowers 40 or 60 will do, for bugs 105 or even better 200mm is better.

Again for technical work, distortion and linearity is important, while working distance not so. Hence for stamps coins and small jewellery the 60mm is the best option, as it has minimum distortion and sharp edge to edge.