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08-25-2009, 07:44 AM   #1
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macro-photography: reverse mounted lens + teleconverter??

hi to all. I'm relatively new here and since I was wondering to buy a teleconverter,
I got the following idea (if I buy a TC..):

I suppose you all know about macro-photography with reverse mounted lenses.

So here is the idea:

1. put a TC on the camera (X1.4 or X2)
2. put a reverse ring on the TC
3. reverse mount a prime lens

What will the result be?? Is this a good idea to get even more magnification or is this completely idiot?

Thanks for helping me on this one.

08-25-2009, 08:04 AM   #2
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QuoteOriginally posted by ezechiel Quote
hi to all. I'm relatively new here and since I was wondering to buy a teleconverter,
I got the following idea (if I buy a TC..):

I suppose you all know about macro-photography with reverse mounted lenses.

So here is the idea:

1. put a TC on the camera (X1.4 or X2)
2. put a reverse ring on the TC
3. reverse mount a prime lens

What will the result be?? Is this a good idea to get even more magnification or is this completely idiot?

Thanks for helping me on this one.
You are not an idiot.

It works, just fine. You'll want to stick to 50mm or shorter for the prime lens.

https://www.pentaxforums.com/forums/post-your-photos/57186-no-money-super-macro-p.html

That's what I got messing around with pretty sub-par kit, with one piece being a 3X TC!

Regards,
Mike
08-26-2009, 03:29 AM   #3
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Well, just bought a 7 element 2X TC on ebay..

Apparently it should be an Elicar one. Someone got info about this brand? Related with Soligor?
08-28-2009, 03:48 AM   #4
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How to check your results

QuoteOriginally posted by ezechiel Quote
hi to all. I'm relatively new here and since I was wondering to buy a teleconverter,
I got the following idea (if I buy a TC..):

I suppose you all know about macro-photography with reverse mounted lenses.

So here is the idea:

1. put a TC on the camera (X1.4 or X2)
2. put a reverse ring on the TC
3. reverse mount a prime lens

What will the result be?? Is this a good idea to get even more magnification or is this completely idiot?

Thanks for helping me on this one.
You will get more magnification. The image will likely be good in the center with some contrast loss due to extra surfaces and some distortion/badness around the edges.

An easy way to test your setup is to photograph a monitor screen & compare center and edge image quality at the same final magnification. Here's an example of such a test:


Shoot with and without the TC; the TC will do better than simply enlarging by the same amount or it won't. The case may differ between center and edges.

It'd be nice if you'd let us knowthe results of your tests.

Dave in Iowa

08-28-2009, 09:53 PM   #5
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Why use a TC, extension tubes would be a better option without loss of IQ (only light).
There are a couple of threads covering Extension tubes and reverse adapters, if you try it out, feel free to post your pics in them.
https://www.pentaxforums.com/forums/mini-challenges-games-photo-stories/61490...ng-thread.html

https://www.pentaxforums.com/forums/mini-challenges-games-photo-stories/70285...sion-tube.html
08-29-2009, 02:03 AM   #6
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I need to get a reversing ring ... although i have some M42 extnesion tubes .... I might screw one of the taks up to it ... and then reverse my 28mm on it too.

One for later on down the track I guess.
08-30-2009, 10:06 AM   #7
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received my K7 yesterday and normally I should receive the reverse ring and the TC this week.
The reason why I bought TC is also to transform my 50-200 to take pictures at 300-350mm. I don't know if after that, I still got good IQ.

Maybe I'll also get some extension tubes (is there a knob or wheel to open diafragm on non-prime lenses?) from *bay. Most sell for 10€. And why get some really expensive tubes at 200€?? Only for getting AF and diafragm settings trough camera??

Anyway, I'll post some pictures with TC and without (reverse macro of course ). When I'll get the extension tubes, I'll do some other experimentation.

I'll take a look at the other threads right away!!

And then go back to the manual of the K7.. Still 300 pages to go...
11-12-2009, 02:48 AM   #8
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I made this one a while ago, it has been taken with a Porst 55mm f1.2 and all three extension tubes (Asahi Pentax)
at f1.2 (will look for ISO and shutterspeed this evening, dont remember and exif's gonebut was handheld).



I'll try to test with XT and reverse this weekend, but this flower is dead a while
ago .. RIP :ugh:


Last edited by ezechiel; 11-12-2009 at 03:02 AM.
04-08-2010, 04:17 PM   #9
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Digging up another old post..
But for those who are interested in extreme macro, I guess this could be interesting!

So, this is the Xtreme macro setup:
body + 3 extension tubes + sigma 24mm Ultra Wide II reverse mounted + Sigma EM 140DG flash
+ Giottos MTL9361B (I recommend this one! bargain for 160€ on amazoon) I just need a head so I can focus more easily (correct spelling?).

Subject: Snowflakes

I'll add to pictures on Flickr tomorrow and add it in here.
04-09-2010, 09:13 AM   #10
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People actually have been stacking lenses for this kind of macro photography.
You can actually stack 2 lenses together (back to back) to get the effect.
04-13-2010, 02:25 PM   #11
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QuoteOriginally posted by GerryL Quote
People actually have been stacking lenses for this kind of macro photography.
You can actually stack 2 lenses together (back to back) to get the effect.
Does this mean that you loose less light than using 3 tubes?
In this case, it would be more interesting.

But what about DOF then? I'm not an optical expert and don't have the courage now
to calculate it But what solution would be more interesting then?
3 extension tubes or lens+reversed lens?

(still need to post that picture.. sorry for the delay)
04-13-2010, 11:36 PM   #12
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QuoteOriginally posted by ezechiel Quote
Does this mean that you loose less light than using 3 tubes?
In this case, it would be more interesting.

But what about DOF then? I'm not an optical expert and don't have the courage now
to calculate it But what solution would be more interesting then?
3 extension tubes or lens+reversed lens?
Light loss is tricky to calculate. At the same magnification, you'd probably lose a bit more light with stacked lenses than with tubes. The basic rule is, your loss in EV or f-stops is M+1. At 1:1, you lose 2 stops. But closing the aperture of a stacked lens changes that, complexly. It's best to take test exposure readings.

The DOF would be razor-thin with either multiple tubes or stacked lenses. You could apply the same M+1 as the Effective Aperture difference. So if you're at f/16 and use 1:1 magnification, you're effectively at f/32. But I'm not sure if that applies to DOF as well as EV.

Extension tubes are cheap and straightforward. To get 1:1 magnification with a 50mm lens, add 50mm of tubes. To get 2:1, add 100mm of tubes. For 3:1, use 150mm of tubes. But that's an awful lot of tubes.

Stacking lenses is also cheap and simple. Use a thread-reversal ring, or just use gaffer's tape to hold the lenses together, front-to-front. The lens on the camera is the PRIMARY, and its aperture must be wide open or your image will be a little circle. The lens stacked on it is the SECONDARY, and its aperture controls the exposure and DOF. That's why a lens designed for stacking might contain a threaded socket to stop-down its iris with an external cable.

Stacking magnification is easy to calculate. It's the ratio PRIMARY : SECONDARY. So with a 105mm primary and a 35mm secondary, magnification is 105:35 or 3:1. Stack a 24mm secondary onto a 135 primary and magnification is over 5.6:1. And you lose about 8 f-stops. And at great magnification, the working distance is VERY VERY CLOSE. Use a sturdy, steady tripod.
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