Reversed lens macro questions

audiobomber · 01-14-2009, 06:40 AM

I have a 28mm lens that won't mount properly on my camera, so I intend to try it for macros. I just ordered a 49mm male to male coupler. The plan is to mount a 49mm filter size prime, and attach the 28mm to the filter threads in reverse orientation. This should give me 1:1 with the 28mm, 1.79:1 with the 50mm and 3.6:1 with the 100mm. I believe that having the inner lens mounted normally will allow auto aperture. I've read about this macro method on the net, but some of the advice was conflicting.

Do I use the reversed lens wide open, or stopped way down? What about the inner lens, what aperture? If the reversed lens needs to be stopped down, what's a good way to hold the aperture in position?

What about focus; both to infinity? Reversed lens focussed to infinity and inner close-focussed? Vice versa? Something else?

What kind of working distances can I expect?

I also ordered a Raynox DCR-150. I already have a Raynox 250 and a 100mm macro. I'll be buying the Pentax teleconvertor whenever it's released mainly for mounting on the 100mm macro. It will be interesting to compare the various macro systems.

elkarrde · 01-14-2009, 06:58 AM

Originally Posted by audiobomber

I have a 28mm lens that won't mount properly on my camera, so I intend to try it for macros. I just ordered a 49mm male to male coupler. The plan is to mount a 49mm filter size prime, and attach the 28mm to the filter threads in reverse orientation. This should give me 1:1 with the 28mm, 1.79:1 with the 50mm and 3.6:1 with the 100mm. I believe that having the inner lens mounted normally will allow auto aperture. I've read about this macro method on the net, but some of the advice was conflicting.

Do I use the reversed lens wide open, or stopped way down? What about the inner lens, what aperture? If the reversed lens needs to be stopped down, what's a good way to hold the aperture in position?

What about focus; both to infinity? Reversed lens focussed to infinity and inner close-focussed? Vice versa? Something else?

What kind of working distances can I expect?

outer, reversed, lens should be always wide open - DOF is controlled by stopping the inner lens. try with f/11, see if the DOF is deep enough, adjust accordingly.

i found focusing rings completely irrelevant (maybe i'm missing something?), focusing is done by physically moving back and forward - possibly with macro bellows.

i've been playing with 28mm lens directly reversed on camera mount, without inner lens, i got few centimeters of working distance - way too close for living subjects. with two lens configuration, it really depends on the inner lens - i don't remember what lenses i used (one was 58mm, can't recall what was the other), but i also had to be very close to my subject.

you'll need massive amounts of light, built-in flash is not a good solution, two lenses are casting pretty big shadow.

audiobomber · 01-14-2009, 10:02 AM

Originally Posted by elkarrde

outer, reversed, lens should be always wide open - DOF is controlled by stopping the inner lens. try with f/11, see if the DOF is deep enough, adjust accordingly.

Interesting, that's the opposite of what I would have guessed. It's defiinitely the easiest thing to do, so that's good.

Originally Posted by elkarrde

i found focusing rings completely irrelevant (maybe i'm missing something?), focusing is done by physically moving back and forward - possibly with macro bellows.

Yes, I always use manual focus and move the camera back and forth. But with the 100mm macro lens, I set the focus ring to the minimum distance. With the Raynox, I set it to infinity. Working with two lenses is four times as confusing.

Originally Posted by elkarrde

with two lens configuration, it really depends on the inner lens - i don't remember what lenses i used (one was 58mm, can't recall what was the other), but i also had to be very close to my subject.

That's too bad. It's hard to get close to some subjects without spooking them (or getting bitten

).

Originally Posted by elkarrde

you'll need massive amounts of light, built-in flash is not a good solution, two lenses are casting pretty big shadow.

I know what you mean. I use a Sigma ST 530 with a diffuser for serious macro, preferably off-camera in wireless mode.

*Blue* · 01-14-2009, 10:31 AM

Another option would be to stack the lenses.

Edit: Here is a link (yeah, I know its a D40): http://www.flickr.com/groups/slrmacr...7606816197434/

and here: http://www.earthboundlight.com/photo...reversing.html

audiobomber · 01-14-2009, 12:20 PM

Originally Posted by Blue

Another option would be to stack the lenses.

I will be stacking lenses (never heard the term before, thanks). That's why I purchased the male-to-male coupler.

That second link is a good'un. Lots of useful info there. Unfortunately it doesn't directly answer my questions regarding aperture, but he did suggest focussing the inner lens to infinity.

*Blue* · 01-14-2009, 01:43 PM

Here is another site with some good info: SlashTips : How to take Extreme Macro with Stacked Lenses - SlashGear

*kristoffon* · 01-14-2009, 04:23 PM

I did some shots like that, only using the 18-250 zoom and 50mm prime.

See my description of the process here: Macro setup on Flickr - Photo Sharing!

And some shots I took here Macro photos - a set on Flickr

*Blue* · 01-14-2009, 09:12 PM

The bee shot is nice!

*falconeye* · 01-15-2009, 05:11 AM

Originally Posted by audiobomber

Do I use the reversed lens wide open, or stopped way down? What about the inner lens, what aperture? If the reversed lens needs to be stopped down, what's a good way to hold the aperture in position?

What about focus; both to infinity? Reversed lens focussed to infinity and inner close-focussed? Vice versa? Something else?

What kind of working distances can I expect?

I am reading some strange responses in this thread... So, let me add my own one

First of all, reverse mounting doesn't make sense if the outer lens isn't short and the inner lens isn't long. I.e., if you don't go for "beyond 1:1 macro". Simply because the DA 35 Ltd. is such a wonderful lens and very inexpensive. It is razor sharp at 1:1 and renders ANY Raynox equipment useless.

So, assume, that the inner lens is long...

Personally, I used a 300mm as the inner lens and a 50mm as outer lens. Providing a 6:1 macro effect.

I HAVE RESOLVED SHARP GREEN LIGHT INTERFERENCE LINES IN A BEE'S EYE!!!

(i.e., resolved down to about 1.5 µm)

Basic lessons learned:

The outer lens must be of premium quality (because any lens defect is magnified 6:1). It must be used at its sweet spot of resolution. I used a Zeiss 50mm which is famous for its outstanding resolving power (400 lp/mm). I stopped it down to f/4 which is where its sweet spot is. Diffraction will start to be disturbing at smaller apertures. Therefore, the outer lens needs a mechanical aperture ring. It is the outer lens which determines DoF.

The inner lens can have any aperture if wider than 6x the outer aperture (i.e., anything wider than f/24). So, forget about inner aperture.

Both lenses set to infinite distance. You focus by changing distance to subject.

The subject to distance is the outer lens focal length (50mm in my case).

Shake: You have as much shake as a 300mm x(1+6) lens (i.e., 2100mm) lens would have. And to make things worse, as much light as f/24.

So, even on a tripod in full sun, I ended up making a series of short exposure ISO1600 shots staking together to one sharp image...

It's challenging. But in the end, you'll get photos you cannot take by any lens or any microscope!

Attachment: A crop from an image where a bee's eye covers about 50% of the image. What you see are the ommatidia making a bee's compound eye. They are totally invisible to a naked human eye, even when using a magnification glass.

*Blue* · 01-15-2009, 01:32 PM

Falconeye,

You lost me with the comment about a 35mm ltd. I don't see where anyone posted anything about it. You are correct in clarifying that it doesn't make sense unless the inner lens is longer than the outer lens. I posted about stacking lenses because that was what audiobomber is describing because reverse mounting a lens is with a single lens. Its also good that you mention the need for a macro focusing rail when stacking lenses.

Edit: I disagree with you on the use of a microscope for magnification though for certain kinds of macro shots. Good scopes can go beyond macro and stack lenses, especially trinocular configurations.

*kristoffon* · 01-15-2009, 01:56 PM

Originally Posted by falconeye

The outer lens must be of premium quality (because any lens defect is magnified 6:1). It must be used at its sweet spot of resolution. I used a Zeiss 50mm which is famous for its outstanding resolving power (400 lp/mm). I stopped it down to f/4 which is where its sweet spot is. Diffraction will start to be disturbing at smaller apertures. Therefore, the outer lens needs a mechanical aperture ring. It is the outer lens which determines DoF.

The inner lens can have any aperture if wider than 6x the outer aperture (i.e., anything wider than f/24). So, forget about inner aperture.

That goes against my experience (18-250 zoom + 50mm reversed) - if I stop down the 50mm below f/2.8 (with the zoom at 250mm) the image circle no longer fills the screen. If I leave it closed at f/22 (min, aperture I think) all I see is a small dot of light in the middle of the viewfinder. Then I use the zoom to control aperture/DOF.

*Igilligan* · 01-15-2009, 01:57 PM

Originally Posted by falconeye

I am reading some strange responses in this thread... So, let me add my own one

First of all, reverse mounting doesn't make sense if the outer lens isn't short and the inner lens isn't long. I.e., if you don't go for "beyond 1:1 macro". Simply because the DA 35 Ltd. is such a wonderful lens and very inexpensive. It is razor sharp at 1:1 and renders ANY Raynox equipment useless.

.

I am confused, are you saying that the raynox lens are useless compared to the da 35 ltd? Or that they are useless on the DA 35 ltd...

Because I have found them to be very useful on all of my primes and even on my P&S. If I dont want to carry the vivi 105 macro, I just throw the raynox in the bag with my old glass.

Here is a shot with the raynox 250 and the fuji s6000

And one with the jupiter 9 85mm and raynox 250

I definately find them more useful than useless. Do I think these kind of shots would compare to the DA 35ltd? I dont have it so I dont know for sure. But.... for a tiny space in the bag, and a tiny nick in the wallet I would not rule out the raynox's.

If I misunderstood you statement... my apologies

*Blue* · 01-15-2009, 02:01 PM

Originally Posted by Igilligan

I am confused, are you saying that the raynox lens are useless compared to the da 35 ltd? Or that they are useless on the DA 35 ltd...

Because I have found them to be very useful on all of my primes and even on my P&S. If I dont want to carry the vivi 105 macro, I just throw the raynox in the bag with my old glass.

Here is a shot with the raynox 250 and the fuji s6000
. . .

And one with the jupiter 9 85mm and raynox 250

. . .

I definately find them more useful than useless.

If I misunderstood you statement... my apologies

I would have been very happy to have had a Raynox for my Nik 5700 3 or 4 years ago! I just never got around to getting one.

audiobomber · 01-15-2009, 02:07 PM

Lots of info here Falconeye, but if you're right then the other advice in this thread is wrong.

I guess I'll have to do my own testing. I pretty much ignore diffraction in favour of DOF when I do macros. Did you try stopping down the outer lens to F16-22?

I could get as high as 3.7:1 using the 100mm/28mm combo, but I would rarely want such extreme magnification and a 28mm working distance would be damn near useless. Even 100mm/50mm with a 2:1 ratio and 2" working distance would be disappointing to me. Is it possible to focus at a distance beyond the front lens' actual FL and get less magnification, or am I stuck with the one set subject distance?

Did you kill that bee to photograph his eye?

audiobomber · 01-15-2009, 02:16 PM

Originally Posted by Blue

Falconeye,
You lost me with the comment about a 35mm ltd. I don't see where anyone posted anything about it. You are correct in clarifying that it doesn't make sense unless the inner lens is longer than the outer lens.

I prefer a 100mm macro lens over a 35mm, for the longer working distance. I tried a 35mm Ltd and I was right on top of my subject to get any decent magnification.

What would be wrong with using the same lens for inner and outer? That will still get you 1:1 macro and a pair of 50mm manual lenses could be done pretty inexpensively compared to a 35mm Ltd.