PDA

View Full Version : Lens Reversal Macro Improvision: DIY Sequel



andrask
01-03-2007, 4:15pm
This is a sequel to the thread: http://www.ausphotography.net.au/forum/showthread.php?goto=newpost&t=3164

The DIY reversing ring has been fabricated and now replaces the "bluetack and rubberband" workaround. :rolleyes: :)

Image 1 (not the best of shots, just adequate) shows the completed ring on the right and the discarded half of the EOS body cap on the left (with evidence of the drill holes on the perimeter). The UV filter can be seen at the bottom of the ring and as can the residue of the glue at the back.

For those without proper workshop facilities (like me), the most effective way of removing the centre portion of the tough body cap is to use a hand-drill with a small diameter drill to perforate the required perimeter and finish off with a Stanley knife.

A glue that effectively bonds the body cap plastic to the metal UV filter is Vise Supergrip Polyurethane Glue (from Bunnings), with a 24-hour curing time. I used my versatile lab retort stand to clamp the ring during this curing time.

Perfectionists could of course paint the residual glue black after carefully sanding it back. So far using the ring as is has not produced any visible artifacts on the macro outcomes.



Image 1

http://img219.imageshack.us/img219/8518/3827diyring6pz4.jpg



Image 2 shows the reversing ring in use. The connection of the reversed lens to the EOS body is secure, testament to the toughness of the body cap material (and the strength of the glue).

To protect the sensitive exposed back-lens, it is covered by its cap between shooting intervals.



Image 2

http://img219.imageshack.us/img219/7273/3825diyringcamera6sk5.jpg

Bax
01-03-2007, 4:41pm
Looks like i may have to invest in a spare body cap.

a) Does the size of the lens matter, which produces better results in terms of macro.. Higher or lower numbers.

b) How do you focus

and finally
c) Do you trust the filter to hold the lens?

andrask
01-03-2007, 5:09pm
Looks like i may have to invest in a spare body cap.

a) Does the size of the lens matter, which produces better results in terms of macro.. Higher or lower numbers.
I mentioned in the original thread (as quoted in the OP) that the magnification varies inversely with the focal length i.e. 28mm will magnify more than 50mm


b) How do you focus
The trick is to set it to the largest aperture for ease of seeing the macro object e.g. in my setup this is f/2.8. After you're satisfied that the focus is correct, you then step down, f/16 in my case to maximise the DoF which will still be very shallow! Otherwise it is rather hard (dark) to see the object properly.

It's all manual so one has to get used to moving the camera forwards and backwards to get it right. For accurate work, I have seen specialists use precision height adjustment gear for their macro work e.g. in scientific macro photography.



and finally
c) Do you trust the filter to hold the lens?
Yes, I do in my setup. The lens goes through a high number of turns on the filter thread before locking up (just make sure your gluing techniques is up to scratch!). Of course it depends to a large extent on the size of your lens as well. As manual primes are preferred in this sort of lens reversal, it should not be an issue.