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gmazza
5th of December 2009 (Sat), 14:06
Please, I don't want to start a cruzade, just pragmatic aproach to the idea.

Have serached about and find very little info about using 180mm macro lenses and diopters or inversed lens, at first the idea really have it's drawbacks:

1. Heavy weight
2. Could use dedicated lens for it (MP-E)
3. There are few diopters and lenses to reverse in the 72mm (filter size) range

But have also some good things, and I wonder why so few people tried it (or at least wrote about it)

1. Longer focal lenght make good use of diopters for easy great magnification.
2. most of these 180mm lenses have 72 mm aperture lenses the hole of a 72mm aperture at, would say, f/16 is bigger than one of 58 or 52mm size, so I expect less diffraction at highter apertures (this in theory I am right or wrong about the diffraction thing ?)
3. Fast and nice recovery of infinite focusing when needed (most places where I do my insect photos are not controled gardens, but wild, is usual to find monkeys, nice birds and other mamals nearby)
4. I'm used to, and like a lot internal focus lenses wich not change in size, personal preference.

Of course is possible to have a MP-E and a tele, but I surely will face sensor dust problems and lost timming for some shoots.

But above all, why so few people tried this ?

Techuser
5th of December 2009 (Sat), 15:55
I might end using my 70-300 for macros as well, but I dont want to loose time even screwing the diopter, I'm initially thinking in continue to use my compact camera for macros, and let the 70-300 with the close-up just for nocturnal outings
Anyway the 180mm for general wildlife will be too short, its too short for birds and monkeys

LordV
5th of December 2009 (Sat), 16:01
Certainly worth trying a dioptre with the lens, only possible drawback would be the weight for handholding at highish mags.

Re the diffraction - my curent understanding after some enquiries with some of the high mag experts, seems that there is no way round the DOF/diffraction relationship by using different lens/tubes or whatever to get the magnification.

Brian V.

gmazza
5th of December 2009 (Sat), 19:46
Thanks for the tele considerations Joćo.

thank you Brian for the info about the diffraction, nice discussion.

Unfortunately today reading more about this I encontered info against the use of diopters in longer focal lenght lenses which could lead to a distortion called frosted glass effect, even vendors bevare of it:

http://www.lmscope.com/produkt22/Kompatibilitaetliste_LM_DSLR_Makroobjektive_en.sht ml

On opposite side Raynox recommends longer focal lenght for the stronger diopter lenses:

http://www.raynox.co.jp/english/digital/d_slr/index.html

Different designs or Am I confused ?

LordV
6th of December 2009 (Sun), 01:07
Thanks for the tele considerations Joćo.

thank you Brian for the info about the diffraction, nice discussion.

Unfortunately today reading more about this I encontered info against the use of diopters in longer focal lenght lenses which could lead to a distortion called frosted glass effect, even vendors bevare of it:

http://www.lmscope.com/produkt22/Kompatibilitaetliste_LM_DSLR_Makroobjektive_en.sht ml

On opposite side Raynox recommends longer focal lenght for the stronger diopter lenses:

http://www.raynox.co.jp/english/digital/d_slr/index.html

Different designs or Am I confused ?

Suspect the frosted glass effect might be a peculiarity of those particular dioptres on particular lenses. Came across these 72mm threaded dioptres which would give you around 2:1 with your macro lens http://www.mitmivec.com/cp/index.php?option=com_virtuemart&page=shop.product_details&flypage=flypage.tpl&product_id=919&Itemid=1&vmcchk=1&Itemid=1

Brian V.