FAQ FAQ  Forum Search   Events   Register Register  Login Login

Macro equipment choices

Author
Dorset Mike View Drop Down
Senior Member
Senior Member

Joined: 20 February 2007
Country: United Kingdom
Location: Poole, Dorset
Status: Offline
Posts: 535
Post Options Post Options   Quote Dorset Mike Quote  Post ReplyReply Direct Link To This Post Topic: Macro equipment choices
    Posted: 15 December 2007 at 21:30
I could do with some comparative information about different macro techniques e.g. pros and cons of ::

using a lens reversed onto the body, what effect on exposure does it have, if any?

using a lens reversed onto another lens, I understand that using say a 50mm lens reversed onto a 100mm would give 2:1, 50mm reversed onto a 200mm gives 4:1, so I assume that 18mm on a 90mm gives 5:1; however what effect does the aperture setting on the reversed lens have on the exposure? say the 18mm is actually the kit lens at 18mm/3.5 and the 90mm is the Tamron 90/2.8 macro.

How does IQ using bellows or tubes compare with IQ from a lens reversed onto another lens?

I have a Tamron 90/2.8 and a set of extension tubes, I also have M42 Bellows and extension tubes and M42 58/2 and 135/2.8 lenses.
Would it be worth my while getting coupling ring(s) to hang the 18-70 kit lens on the Tam 90/2.8, so retaining auto exposure (I think), (would a kit lens or my Tam 17-50/2.8 fitted via coupling rings put too much strain on either the filter threads or the camera mount), or should I concentrate on the bellows/tubes for additional magnification?

Cheers MIKE
Cheers MIKE,



5D, A350: 50/1.7; 28-75/2.8;80-200/2.8 APO Kit; 500/8; Tam 17-50/2.8; 18-280; 70-300/4-5.6: 90/2.8; MC7 2X; Tokina 11-16/2.8: 80-400/4-5.6; Kenko 1.4X:
Min A200 bridge
 



Back to Top
wetapunga View Drop Down
Senior Member
Senior Member

Joined: 02 September 2007
Country: New Zealand
Location: New Zealand
Status: Offline
Posts: 5110
Post Options Post Options   Quote wetapunga Quote  Post ReplyReply Direct Link To This Post Posted: 07 January 2008 at 20:35
Originally posted by Dorset Mike Dorset Mike wrote:

I could do with some comparative information about different macro techniques e.g. pros and cons of : (snip)

Cheers MIKE


All good questions, and all relating to pushing your magnification ratio above 1:1 (which the Tamron already delivers).

Let me first say, that the quest for AF at >1:1 is going to be largely futile. You will get far more success at locking on to the subject with manual focus. At high magnification ratios, the precise focal plane is going to be a big problem. AF will generally not lock on at all to the subject (if your technique permits it).

Example:
- I actually wanted the top eye to be in sharpest focus, but got the bottom eye instead. Click the picture to see the 800px version.

The actual photo is 2400 pixels across by the way, which should give you some idea of how much I've magnified it.

I eschewed the macro reversing ring for several reasons. Your mileage may vary. First, I didn't have a decent 50mm prime lens. Second, if I got one, it was one more lens to look after while in the bush or overseas. Third, I was concerned about the weight at the end of the Tamron. It's a good lens, but even so...Plus, you're now limiting yourself with macro ringlights or flashes.

One of the big problems however, with the extension tubes or reversing ring (at greater than 1:1), is you start with a tiny field of view. You can spend a long time moving the camera about, trying to find the subject. Who may not appreciate this big lens waving around in front of them and take fright...

For what it's worth I ended up getting the Raynox micro adapter set. These are superb on a 55mm lens, but produce serious vignetting on a 62mm. I use the 6X magnifier on my Tamron most of the time.

Addendum: the 90mm Tamron over 18mm kit lens should give a magnification ratio of 5:1, but you need to figure out how to attach the kit lens on to the Tamron, with the kit-lens aperture 'wide open'. Obviously the camera won't do it for you .




Edited by chthoniid - 07 January 2008 at 22:35
a7R, a77ii, QX100 | Minolta 17-35mm G, 20mm, 35-105mm O, 50mm M, 70-210 beercan, 85mm G, 100mm M, 300mm G | Sony 16-50mm, CZ16-80mm, 70-200mm G, 135mm f2.8 STF | Tokina 11-16mm
Back to Top
Dorset Mike View Drop Down
Senior Member
Senior Member

Joined: 20 February 2007
Country: United Kingdom
Location: Poole, Dorset
Status: Offline
Posts: 535
Post Options Post Options   Quote Dorset Mike Quote  Post ReplyReply Direct Link To This Post Posted: 09 January 2008 at 17:02
I have now managed to get hold of a few rings and had a bit of a "play"

So far I have tried a reversing ring to mount various lenses direct to the camera, most success has been surprisingly with the 18-70 kit lens.

A coupling ring joining the kit lens reversed onto the Tamron 90 so far I've not had any useable results, probably a combination of working distance and DOF working against me.



The above was taken using the 18-70 @17mm reversed direct onto the camera using an MAF>55m ring and setting the aperture by means of a modified lens cap as shown on Pete Ganzel's site
see here

Apart from showing I need more practice focusing this rig and also need a sensor clean, I was able to work out the magnification by counting the number of pixels then multiplying by 0.29mm per pixel and dividing the result into the sensor size, to get a magnification of about 4X which is about what I expected. I rounded the figures slightly as I was not after absolute accuracy as getting some idea of the magnification of various focal lengths.

Sony 19" LCD screen width 380mm, 1280 pixels = 0.29 pixel size, pic
20 pixels wide =5.8mm, 5D sensor 23.5mm wide. Tripod and focussing rail used.

The reason I chose this method to experiment is that I did not have to worry about lighting, the screen provides sufficient, also I thought using a ruler or other common measuring device, or picture thereof, might not be as accurate as the scale divisions may not be fine enough, the 0.29 pixel size works for me, also on clear white or light grey screens the 3 separate colours in each pixel give near enough 0.1mm divisions.

Thought --- would a shot of a plain white or grey screen be any use for checking lens distotions and edge sharpness?
Are there any errors in my assumptions for this method of testing? I will try and refine things a bit and work out the magnifications at other lengths also check if there is any difference between different lenses at the same focal length.

Any clues to getting results from coupled lenses?

Cheers MIKE,



5D, A350: 50/1.7; 28-75/2.8;80-200/2.8 APO Kit; 500/8; Tam 17-50/2.8; 18-280; 70-300/4-5.6: 90/2.8; MC7 2X; Tokina 11-16/2.8: 80-400/4-5.6; Kenko 1.4X:
Min A200 bridge
Back to Top
Dorset Mike View Drop Down
Senior Member
Senior Member

Joined: 20 February 2007
Country: United Kingdom
Location: Poole, Dorset
Status: Offline
Posts: 535
Post Options Post Options   Quote Dorset Mike Quote  Post ReplyReply Direct Link To This Post Posted: 09 January 2008 at 17:11
The above pic is not cropped, just a downsize.
Cheers MIKE,



5D, A350: 50/1.7; 28-75/2.8;80-200/2.8 APO Kit; 500/8; Tam 17-50/2.8; 18-280; 70-300/4-5.6: 90/2.8; MC7 2X; Tokina 11-16/2.8: 80-400/4-5.6; Kenko 1.4X:
Min A200 bridge
Back to Top
H20boy View Drop Down
Senior Member
Senior Member

Joined: 19 March 2006
Location: United States
Status: Offline
Posts: 1486
Post Options Post Options   Quote H20boy Quote  Post ReplyReply Direct Link To This Post Posted: 11 January 2008 at 02:21
Add any extension tubes?...the mag factor will increase.
Matt - TX l Maxxum-m42 adapter - that's it   :(     l My Galleries
Back to Top
Dorset Mike View Drop Down
Senior Member
Senior Member

Joined: 20 February 2007
Country: United Kingdom
Location: Poole, Dorset
Status: Offline
Posts: 535
Post Options Post Options   Quote Dorset Mike Quote  Post ReplyReply Direct Link To This Post Posted: 13 January 2008 at 01:11
Matt, no extension tubes, just the reversed lens, I do have 2 sets of tubes, one MAF the other M42, also have M42 bellows which usually have a Helios 58/2 on them, must try reversing that sometime. Just trying to get as much bang (read magnification) for the buck as I can.

Cheers MIKE,



5D, A350: 50/1.7; 28-75/2.8;80-200/2.8 APO Kit; 500/8; Tam 17-50/2.8; 18-280; 70-300/4-5.6: 90/2.8; MC7 2X; Tokina 11-16/2.8: 80-400/4-5.6; Kenko 1.4X:
Min A200 bridge
 



Back to Top
wetapunga View Drop Down
Senior Member
Senior Member

Joined: 02 September 2007
Country: New Zealand
Location: New Zealand
Status: Offline
Posts: 5110
Post Options Post Options   Quote wetapunga Quote  Post ReplyReply Direct Link To This Post Posted: 29 January 2008 at 04:59
Aah, first up, I think I didn't read your first message properly and offered a lot of pointless advice. I can only say I was on a rush to get away and have only just returned from a PC-free holiday. Apologies.

Have you been able to deduce any way to estimate the magnification ratio from using a reversing ring with a lens? Have you had any more luck with the Tamron?
a7R, a77ii, QX100 | Minolta 17-35mm G, 20mm, 35-105mm O, 50mm M, 70-210 beercan, 85mm G, 100mm M, 300mm G | Sony 16-50mm, CZ16-80mm, 70-200mm G, 135mm f2.8 STF | Tokina 11-16mm
Back to Top
Dyxum main page >  Forum Home > Dyxum Community > Knowledge Base

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.078 seconds.

Monitor calibration strip

Dyxum.com - Home of the alpha system photographer

In memory of Cameron Hill - brettania

Feel free to contact us if needed.