Some of the things that I shoot are either dangerous (fire), or messy (lots of splatter). So I want to build a rig for doing moderate magnification macro at a distance.
Here is my current plan. I have a 600 mm f/4 telephoto lens. So if I mount that to a long optical rail, and arrange 600 mm of extension, I should have a 1:1 macro lens with 1.2 meters from entrance pupil to subject.
If I use a 300 mm f/2.8 with the same extension, I will get a 2X macro, albeit with much shorter working distance.
I plan to achieve the extension with a combination of a view camera bellows and a piece of black ABS plastic pipe. The bellows helps with focus. The pipe is helpful because I don't need bellows for the part that won't change.
For fire or hot stuff I may need to use a piece of IR blocking glass in front of the set up to avoid cooking the sensor.
I will put the camera on a stackshot for stacking.
Anybody have:
1. Experience with such a set up?
2. Alternative suggestions?
3. Concerns?
Nathan
very long working distance macro
Moderators: rjlittlefield, ChrisR, Chris S., Pau
very long working distance macro
nathanm
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Onlineenricosavazzi
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In theory it will work, in practice the lens at 1x will work far enough from its design parameters that it may perform poorly.
An alternative would be a long repro lens or large format enlarger lens, which at 1x would work closer to its design parameters. I believe there are some copy lenses, like Apo Nikkors, up to 800 mm FL, and I have a couple of 360 mm enlarger lenses (Componon S and Rodagon) in my collection, so there might be even longer ones. Some of these lenses, like the Componon S, are described as diffraction-limited at the center of their image circle.
Using these lenses would require the construction or cobbling up of an optical bench to carry camera and lens at appropriate distances, and a long extension tube (a cardboard tube painted flat black and carrying a few internal baffles cut out of black stock cardboard should do).
On Micro 4/3, the Olympus 300 mm f/4 Pro focuses down to 0.48x (which means in practice a subject area of about 36 x 27 mm), without extension tubes and with very good image quality. It uses internal focusing and I have not measured its actual FL at this magnification, but Olympus quotes a minimum focusing distance of 1.6 m (i.e. about 1.3 m working distance). It also takes a 1.4x teleconverter (and therefore 0.67x), still with very good image quality, so it seems to approach your goals with no need of custom adaptations.
An alternative would be a long repro lens or large format enlarger lens, which at 1x would work closer to its design parameters. I believe there are some copy lenses, like Apo Nikkors, up to 800 mm FL, and I have a couple of 360 mm enlarger lenses (Componon S and Rodagon) in my collection, so there might be even longer ones. Some of these lenses, like the Componon S, are described as diffraction-limited at the center of their image circle.
Using these lenses would require the construction or cobbling up of an optical bench to carry camera and lens at appropriate distances, and a long extension tube (a cardboard tube painted flat black and carrying a few internal baffles cut out of black stock cardboard should do).
On Micro 4/3, the Olympus 300 mm f/4 Pro focuses down to 0.48x (which means in practice a subject area of about 36 x 27 mm), without extension tubes and with very good image quality. It uses internal focusing and I have not measured its actual FL at this magnification, but Olympus quotes a minimum focusing distance of 1.6 m (i.e. about 1.3 m working distance). It also takes a 1.4x teleconverter (and therefore 0.67x), still with very good image quality, so it seems to approach your goals with no need of custom adaptations.
--ES
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rjlittlefield
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I'm not sure they cover the range you care about, but take a look at http://www.company7.com/questar/microscope.html .
--Rik
--Rik
One reason that I wanted to start with the 600 mm f/4 lens is that after extension I will still only be at an effective f-stop of f/8 at 1X.
The big process lenses are typically f/9 to start with which will take me to f/18 effective so I worry about diffraction.
That said, I bought a 610mm apo nikkor on ebay last night to try it.
The big process lenses are typically f/9 to start with which will take me to f/18 effective so I worry about diffraction.
That said, I bought a 610mm apo nikkor on ebay last night to try it.
nathanm
Re: very long working distance macro
Nathan,
Yours is an interesting proposition. Now that you bring it up, I'm tempted to experiment with my own 600mm f/4 Nikkor in a similar manner.
While sensible of Enrico's well-founded observation that taking this lens so far out of its design intent courts bad performance, whether or not this would occur in practice can only be determined by testing. (As Enrico would no doubt agree.) For those who already have the equipment, such tests don't risk much.
My own preference would be to test with flocked pipe and a Nikon PB-6 bellows plus Nikon PB-6E extension, rather than a flocked pipe plus large-format bellows such as you posit. Either should work, of course. And incumbent in this choice is what equipment the tester has on hand. I have a PB-and PB-6E, while you certainly have large format bellows equipment. But the Nikon PB-6 equipment strikes me as mechanically more straightforward, while permitting up to 437mm of adjustable extension (for details, see Enrico's documentation here).
Regardless of bellows choice, I'm wondering about how much working distance this arrangement would allow. While it's easy to calculate WD for a thin lens model, my guess is that 600mm f/4 Nikkor lenses differ substantially from thin lens models. (And individual models in this series of lenses probably differ from one another.)
Cheers—and please let us know what you find if you explore this further!
--Chris S.
Yours is an interesting proposition. Now that you bring it up, I'm tempted to experiment with my own 600mm f/4 Nikkor in a similar manner.
While sensible of Enrico's well-founded observation that taking this lens so far out of its design intent courts bad performance, whether or not this would occur in practice can only be determined by testing. (As Enrico would no doubt agree.) For those who already have the equipment, such tests don't risk much.
My own preference would be to test with flocked pipe and a Nikon PB-6 bellows plus Nikon PB-6E extension, rather than a flocked pipe plus large-format bellows such as you posit. Either should work, of course. And incumbent in this choice is what equipment the tester has on hand. I have a PB-and PB-6E, while you certainly have large format bellows equipment. But the Nikon PB-6 equipment strikes me as mechanically more straightforward, while permitting up to 437mm of adjustable extension (for details, see Enrico's documentation here).
Regardless of bellows choice, I'm wondering about how much working distance this arrangement would allow. While it's easy to calculate WD for a thin lens model, my guess is that 600mm f/4 Nikkor lenses differ substantially from thin lens models. (And individual models in this series of lenses probably differ from one another.)
Remembering that these lenses have a drop-in filter slot, might it work better to place the IR-blocker in the drop-in slot, rather than in front?nathanm wrote:For fire or hot stuff I may need to use a piece of IR blocking glass in front of the set up to avoid cooking the sensor.
My concerns would be mechanical. As you undoubtedly know, 600mm f/4 lenses are big, long, and heavy. I can’t begin to hand-hold mine, so always use it on a gimbal mount. It’s a good bet that you also have a gimbal mount for your lens. If I were repurposing my lens for macro use, I’d put it on the gimbal mount, and bolt this mount onto an extremely robust articulated arm or gantry. My guess is that you’ve already considered this.nathanm wrote:Concerns?
Cheers—and please let us know what you find if you explore this further!
--Chris S.
I bought a 2 meter section of the Thorlabs 66mm optical rail. We'll cut a piece of that for the base.
The 600 mm lens will attach directly to the rail - the Thorlabs rail is compatible (enough) with the RRS foot I have on the lens.
Stackshot will hold the camera, and will do the focusing. The 8" rail stackshot should give me plenty of focusing range.
The bellows does not support anything since both the lens and camera are separately supported.
The whole thing will go on a cine style gear head on a studio stand. I might use the manfrotto long lens support leg if necessary.
Small differences in alignment ought to be compensated by stacking.
I will use either Canon full frame, or my PhaseOne - I think at 1:1 the image circle will be plenty big enough.
I thought about putting the IR filter in the drop-in slot. Two issues with that. First, might get a lot of heat in the front elements upstream of the filter. Second, the filter might get hot and it is hard to access or cool there. Pieces of IR filter big enough seem to be readily available.
Thin lens formula won't be correct, but ought to have some working distance.
Same set up can handle the 610 mm apo nikkor process lens I just bought, but will need a bit more extension. It will be interesting to see which one works best.
The 600 mm lens will attach directly to the rail - the Thorlabs rail is compatible (enough) with the RRS foot I have on the lens.
Stackshot will hold the camera, and will do the focusing. The 8" rail stackshot should give me plenty of focusing range.
The bellows does not support anything since both the lens and camera are separately supported.
The whole thing will go on a cine style gear head on a studio stand. I might use the manfrotto long lens support leg if necessary.
Small differences in alignment ought to be compensated by stacking.
I will use either Canon full frame, or my PhaseOne - I think at 1:1 the image circle will be plenty big enough.
I thought about putting the IR filter in the drop-in slot. Two issues with that. First, might get a lot of heat in the front elements upstream of the filter. Second, the filter might get hot and it is hard to access or cool there. Pieces of IR filter big enough seem to be readily available.
Thin lens formula won't be correct, but ought to have some working distance.
Same set up can handle the 610 mm apo nikkor process lens I just bought, but will need a bit more extension. It will be interesting to see which one works best.
nathanm
As I'm sure you know, this lens will need approximately 610mm from the sensor to obtain infinity focus, and an additional 610mm to get 1X magnification, but it sounds as though you have the tools and the time to accomplish this. Good luck with the project!nathanm wrote:One reason that I wanted to start with the 600 mm f/4 lens is that after extension I will still only be at an effective f-stop of f/8 at 1X.
The big process lenses are typically f/9 to start with which will take me to f/18 effective so I worry about diffraction.
That said, I bought a 610mm apo nikkor on ebay last night to try it.
David
This is entirely gratuitous, but I am in Australia on a trip and was at a wetlands area. I was using a 600 mm f/4, mostly for birds. There were quite a few dragonflies. Unlike shooting them on cold mornings when they can't fly, it was 34C out and there were flying fast, but occasionally would land.
So I popped on a 2X teleconverter and took "macro" shoots with that combination. Here is an example (cropped).
This is quite different than the set up that I started the thread about, but still, it is using a long lens as a kind of macro lens...
So I popped on a 2X teleconverter and took "macro" shoots with that combination. Here is an example (cropped).
This is quite different than the set up that I started the thread about, but still, it is using a long lens as a kind of macro lens...
nathanm
You could try with a short automatic extension tube on your 600mm prime lens. It works ok with my Canon 400mm f5.6.
Regards Jörgen
Regards Jörgen
Jörgen Hellberg, my webbsite www.hellberg.photo
Have you considered this: http://www.photomacrography.net/forum/v ... hp?t=32026
My extreme-macro.co.uk site, a learning site. Your comments and input there would be gratefully appreciated.
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rjlittlefield
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effective f# for microscope objectives
Johan,
A quick note, related to one of your Extreme Macro calculators...
Take a look at the discussion at http://www.photomacrography.net/forum/v ... 869#199869 , and especially at http://www.photomacrography.net/forum/v ... 511#196511 which is linked there.
Gotta run...
--Rik
A quick note, related to one of your Extreme Macro calculators...
Take a look at the discussion at http://www.photomacrography.net/forum/v ... 869#199869 , and especially at http://www.photomacrography.net/forum/v ... 511#196511 which is linked there.
Gotta run...
--Rik
