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Old Jun 4, 2010, 1:19 AM   #11
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Originally Posted by rhermans View Post
just a caveat, don't overestimate the power of extention tubes with long lenses.

ex. a lens of 200mm, that does a magnification of 1:2 (0.5) will give you a magnification of 1:1 if you add an extention tube of 100mm.

the longer the lens the less inpact of the extentiontube, a 50mm lens with a magnification of 1:2 (0.5) will give you with an extention tube of 50mm a 3:2 (1.5) magnification.

The math isn't 100% true but close enough.

Ronny
True, it's very hard to get 1:1 with tubes and long lenses. Of course a 50mm tube length on a 200mm and a little crop will get you to 1:1 as well. Nothing that says you can't do it that way. In fact shooting at lower magnifications on slide and then shooting the slide zoomed in was a common practice. Someday I will try it. Anyway, to me the easiest way to get 1:1 is a reversed 50mm on 25mm of tubes.

John
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Old Jun 4, 2010, 3:05 AM   #12
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Originally Posted by jasonholland89 View Post
more curiosity than anything... did any comapanies ever do any manual 1:1 macro lenses. i was going to save up and buy a 1:1 lense in a few months, but seeing as most of my super close up stuff has only ever been manual anyway, is there any older models that might still be about?
You need to do manual focus for macro anyway. So manual macro lens will not be very cheap compared with AF ones


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Old Jun 4, 2010, 4:12 AM   #13
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manual more expensive than af?


anyway.... sorry i havnt answers all your questions, been away for a few days as previously said on another post.

when i do macro i normally use the lense for macro only, i wouldnt use it for anything else. The lense i use at the mo is a reversed 28mm lense which has been working quite well. will post pics up shortly. I use this lense normally for wide angle night time shots as it has a lowish f of 1.8 or 2... something like that. low enough anyway.

i would like to try some of my other lenses, like my 135mm reversed, but im still waiting for some of my reversing rings and couplers to be delivered so cant test them all yet. i do have extention tubes as well, and a 2x vivitar lense, which ive only used with my tamron 70-300mm lense.

as for macro rings, there is 2 types, and one is usable with reversed rings as it doesnt actually attach to the lense itself. id only buy and use that for reversed rings tho as it would prob be the only real use for that kind as its prob not all that great.
at the mo im using the normal flash or an external one, depending on where i am.

as for what i take pics of, i will show you soon, but i have a big thing for eyes for some reason, alot of which tend to be reptile eyes, but also human lol. and insects. (i have reptiles, spiders etc as pets so im always taking pics of them) but thats the main macro things i take.

think thats the majority of what you asked. and cheers for all the info on here. turning into quite an interesting topic
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Old Jun 4, 2010, 2:13 PM   #14
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got some pics sorted, these arent the best as im still learning to use the reversed lenses and extention tubes, but ill improve. the majority of these are done with a reversed 24mm 1.8 tokina lense. the only one that i can reverse properly at the moment as im waiting for other reversal rings to arrive.

and before you say is... yes i need to clean my lense lol





moth - 1st pic to show size, and as the moth was on my hand, it was difficult to balance, hense the not amazing pics.




a few eyes, water dragon - crested gecko - girlfriend






Last edited by jasonholland89; Jun 4, 2010 at 2:16 PM.
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Old Jun 5, 2010, 1:20 AM   #15
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Love the eye shots. No point in reversing anything over 50mm, the longer the lens the less the magnification and a reversed 135mm may not even work, I've never been able to get any zoom to focus in reverse beyond 70 or 80mm. Even if it did you'd be feet away from the subject. Better use would be to get a coupling ring and stack the 28mm on the 135 and have almost 5X power.

You've got some good ideas and a good eye, pardon the pun, for macro. Have fun with whatever you end up using.

John
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Old Jun 14, 2010, 11:44 AM   #16
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any one know anoything about Sigma 50mm Macro 2.8. the 1990 version? so the (i presume) manual only. i got a good deal on a near perfect one. for 80 something quid. should arrive soon. any one have any views on it? owned one etc.
anyway so i know have a 1:1 manual macro lense. but now i have a new question... reversing a 1:1 macro lens. would this act the same way as a normal lens, making the magnification even greater?
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Old Jun 15, 2010, 6:36 PM   #17
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okay,
it takes 50mm ETs to give you 1:1 mag.. 50mm/50mm = 1
a 100mm lens will give you 1/2..
i've shot macros with just about every setup you can think of except a bellows.
if you want to know how much mag you get from some of the esoteric setups then shoot a MM ruler. at 1:1 you should get 23.5mm of the ruler because that's how big your sensor is. 47mm = 1:2.
my avatar is shot with a 2xTC + 68mm ETs. it's uncropped.. some where around 4-5:1.. here's a couple with the reversed 50mm..






i built all these adapters. the reversed also allows me to add filters, caps, ect...
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Old Jun 15, 2010, 6:49 PM   #18
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how do you add filters to a reversed lense? thats one thing ive been trying to sort out. and not 100% sure what you mean about the reversing, as i was on about reversing a lense that can do 1:1 macro anyway... so it can do 1:1 without filters or being reversed etc. but what i as wondering, was if it can do 1:1 normally, could this magnifation be increased if it reversed?
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Old Jun 16, 2010, 2:51 PM   #19
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I don't know if it is still available, but Pentax used to make an adapter that I believe is called a 'reverse ring light holder' I don't have mine with me at the moment, it might be called 'reverse ring light adapter'. It attaches to the K mount end of the reversed lens and it had threads on the other side to hold a ring light, but you can also attach filters to it.

Steve
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Old Jun 16, 2010, 3:51 PM   #20
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so they do exsist then... cant find any tho. 'reverse ring light holder' didnt find anything either... dunno if it would be difficult making one? or are there otehr companies taht have ever made them.
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