What tube do I need?

Hey everyone I got a Sony FE 50mm 1.8 on my A7 and I'd like to minimize the minimum focus to at least half of what it is.


Which tube would help me achieve that? 10mm,16mm or 26mm?


The current MFD is 1.48 ft (0.45 m)

Also can anyone tell me what the magnification with the tubes it will be? Or what is the formula?

The current magnification is 0.14 x

Thanks!

anyone?

Normally(excluding internal magnification) you need the same amount of extension as the lens to get 1x(lifesize) -- 50mm lens needs 50mm extension for 1x and 25mm for 1/2x. Your best bet would be to buy a set of extension tubes as this will give you most flexibility with other lenses as well. My first option would be a macro lens, the next option is extension tube(s). Tubes are the best option to get your feet wet. Will tell you that if you end up liking macro your next purchase will be the macro lens, they are so much more versatile and flexible than extension tubes.

The formula is extension divided by lens focal length. The 10 will give you .34x, 16 will give you .46x, 26 will give you .66x.

Thank you!!!!

CheleA wrote in post #18004251
Normally(excluding internal magnification) you need the same amount of extension as the lens to get 1x(lifesize) -- 50mm lens needs 50mm extension for 1x and 25mm for 1/2x. Your best bet would be to buy a set of extension tubes as this will give you most flexibility with other lenses as well. My first option would be a macro lens, the next option is extension tube(s). Tubes are the best option to get your feet wet. Will tell you that if you end up liking macro your next purchase will be the macro lens, they are so much more versatile and flexible than extension tubes.

I've own some EF extension tubes for my Canon, along with 1:1 and 1:2 lenses, in the past. Just never got deep into macro and didnt know the science behind it. Thank you so much for the information!

Having been used to 12" MFD on my other 50mm lenses it feels super long on this lens that can only do 18". Dont really want it for any intense macro work, just wanted to focus a bit closer when doing product shots.

NateD wrote in post #18004252
The formula is extension divided by lens focal length. The 10 will give you .34x, 16 will give you .46x, 26 will give you .66x.

The above bold text defines the magnification if the lens is focused to Infinity. 25mm extension/50mm FL = 0.5X. NateD did supply the magnification values with various lengths of extensions, but I have not seen an equation to calculate the new effective minimum focus distance with each length of tube...I simply consult a calculator
http://www.kielia.de/p​hotography/calculator/
to get the following values...

In the case of the Canon 50mm f/1.8 its closest focus distance is 0.45m, allowing a native magnfication of 0.15X;

• with 25mm extension the magnification achieved is 0.5X with lens focused at Infinity
  
• with 25mm extension, the minimum effective focus distance is 0.211m, achieving 0.65X at minimum focus distance;
  
• with 10mm extension, the magnification achieved is 0.33Xand the minimum effective focus distance is 0.266m
  

• magnification range: ~0.14X (lens direct on body), ~0.49X - ~0.62X
  
• working distance (front of lens to subject plane): 10.0-12.4cm, 3.9-4.9"