Next steps to improve magnification?
Moderators: rjlittlefield, ChrisR, Chris S., Pau
Next steps to improve magnification?
I have been stacking macro images from a Pentax K-50 with their 100mm 1:1 macro lens for a while now. I would like to check out some other options to improve magnification. I got some used extension rings, and a 2x teleconverter. The lens assembly is getting long and heavy. I would guess I am some where in the 2.5x-3x area. I like the amount of magnification, but I would like to try more. When you get used to the sharpness from the standard macro lens kludging all these parts together certainly does not help with sharpness. Keeping the camera stable and stationary I am sure gets to be more of an issue the higher you go. If I had a Nikon or Canon I my have more options. With Pentax I would appreciate suggestions on the next logical steps to gain magnification and sharpness.
If I may provide my amateur opinion... the issue with using extension tubes or teleconverters on consumer system lenses that are designed to provide at most 1:1 magnification, is twofold. First, the effective aperture becomes quite small and diffraction is high. Second, the lens is being used in a way that it was not intended to be used. Using extension tubes, for instance, decreases the working distance, and these lenses aren't optimized for imaging in that regime.
Moreover, consumer macro lenses are almost always designed to with a focusing group--in other words, they're generally optimized for a variety of magnifications from 1:1 to infinity focus.
You can actually get a lot of mileage out of reversing certain consumer lenses. But, ultimately, I made the conclusion that to get to higher magnifications, I had to go with an apochromatic, infinity-corrected, long working distance microscope objective. It's not for the faint of heart--I found the process of sourcing all the components to be quite frustrating, even with the very generous and useful help of other forum members. But once I got it up and running, it was a remarkable improvement.
The only thing I would say is that if you make the leap, you're going to get hooked. You're going to want to see what you can get out of even more magnification! Good luck!
Moreover, consumer macro lenses are almost always designed to with a focusing group--in other words, they're generally optimized for a variety of magnifications from 1:1 to infinity focus.
You can actually get a lot of mileage out of reversing certain consumer lenses. But, ultimately, I made the conclusion that to get to higher magnifications, I had to go with an apochromatic, infinity-corrected, long working distance microscope objective. It's not for the faint of heart--I found the process of sourcing all the components to be quite frustrating, even with the very generous and useful help of other forum members. But once I got it up and running, it was a remarkable improvement.
The only thing I would say is that if you make the leap, you're going to get hooked. You're going to want to see what you can get out of even more magnification! Good luck!
A very high quality teleconverter should be better than extension tubes, because (among other things) it still lets the moving internal lens groups of the main lens stay in the right places for correcting the image at that lens-subject distance. The working distance isn't changed by the teleconverter. This is true even for a lens with no moving groups, if it is optimized for a certain magnification and if adding extension moves it away from that optimum.
I am not sure your only option is to take the big (and rather expensive) step upwards to "apochromatic, infinity-corrected, long working distance microscope objective" (read Mitutoyo).
Many members of this site have shown excellent images made with the LOMO 3.7x NA 0.11 microscope objective. It is avaiable for around $50 and since it is finite corrected, you just need a set of bellows and an RMS adapter to be ready for work.
For $200-400 you can get excellent used Nikon objectives for 4x or 10x magnification. Dreaming af higher magnifications is to ask for fast growing troubles with vibrations, lightning, working distances and object mounting.
It might be a good idea to check your needs and polish your skills before making the serious big investments.
Many members of this site have shown excellent images made with the LOMO 3.7x NA 0.11 microscope objective. It is avaiable for around $50 and since it is finite corrected, you just need a set of bellows and an RMS adapter to be ready for work.
For $200-400 you can get excellent used Nikon objectives for 4x or 10x magnification. Dreaming af higher magnifications is to ask for fast growing troubles with vibrations, lightning, working distances and object mounting.
It might be a good idea to check your needs and polish your skills before making the serious big investments.
Troels Holm, biologist (retired), environmentalist, amateur photographer.
Visit my Flickr albums
Visit my Flickr albums
It all depends on what magnification you want, and how much you can spend. If you want 7-10x, I think the best thing is to spend the money on an objective that you will never have to upgrade, and that would be the Mitu 7.5x or 10x. You'll be happy with it forever. If you buy something less good, you'll eventually go through several iterations of objectives trying to improve your results, and in the end you'll have spent more than you would have spent by getting something really good to start with.
Lomo 3,7x is a cheap gem one should definitely have while they are still available for the price and quantity of today. Bellows is versatile and if you can get it cheap, just get one. Other way is to buy Pentax to M42 adapter and cheap M42 extension rings and then M42 to RMS adapter.Troels wrote:Many members of this site have shown excellent images made with the LOMO 3.7x NA 0.11 microscope objective. It is avaiable for around $50 and since it is finite corrected, you just need a set of bellows and an RMS adapter to be ready for work.
- Rane
For the price, and if images primarily posted on the www, it's hard to beat a reversed 28mm on bellows.
http://www.photomacrography.net/forum/v ... hp?t=38383
works equally well without the TC1.4
http://www.photomacrography.net/forum/v ... hp?t=38383
works equally well without the TC1.4
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
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MarkSturtevant
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On the issue of weight with a 'long' set up, I can suggest looking into the Pixco helicoid macro extension tube ( https://www.amazon.com/Pixco-Adjustable ... nsion+Tube ). This variable length extension tube has a lot of reach, and its all aluminum build makes it very light. It can be fairly easily used in the field since it is light and rigid. There are some set ups floating around in this site that use it, including a super macro lens that I had built that gets up into the range you were wanting. Warning: You are going to have to creatively flock the heck out of the insides.
Mark Sturtevant
Dept. of Still Waters
Dept. of Still Waters
There are some respectable Nikon 4x and 10x new objectives well under $100:
http://www.photomacrography.net/forum/v ... hp?t=27205
http://www.photomacrography.net/forum/v ... hp?t=27205
Chris R
Thanks for all the good suggestions. A follow up question would be how do you end up mounting say a microscope lense to my Pentax? I would guess they have no aperture control. Will I need a massive amount of light to make these lenses work. I would like to use the images for photogrammetry. Will there be a lot of lense distortion? Photogrammetry software is suppose to be able to adjust for lense issues, but would need to understand how to define the distortion to make adjustment while building the 3D data.
I missed the post from rolsen about converting to Pentax M42, and using macro bellows or rings. With a set up like this does the camera assembly need a rail to move the entire unit for focus steps?
I missed the post from rolsen about converting to Pentax M42, and using macro bellows or rings. With a set up like this does the camera assembly need a rail to move the entire unit for focus steps?
Yes, some kind of rail is needed to move the whole setup. Here's a sample of my Canon with bellows and microscope lens in front, couple of M42 tubes between it and bellows. There's adapter between camera and bellows, between bellows and M42 tubes, and finally M42 to RMS adapter to Nikon lens.CarlW wrote: I missed the post from rolsen about converting to Pentax M42, and using macro bellows or rings. With a set up like this does the camera assembly need a rail to move the entire unit for focus steps?
Bellows_2 by Rane Olsen, on Flickr- Rane
Check the FAQs, Carl, several will help, eg
FAQ: How can I hook a microscope objective to my camera?
and others on how to focus, rigs, etc.
WHen you go closeyou tend to get a more distant perspective on things, perhaps surprisingly.
Flash is an easy answer to lighting and preventing vibrations. You'll need a lot of DIY diffusion of the light; paper, yoghurt pots etc.
The optics are the easy bit!
FAQ: How can I hook a microscope objective to my camera?
and others on how to focus, rigs, etc.
WHen you go closeyou tend to get a more distant perspective on things, perhaps surprisingly.
Flash is an easy answer to lighting and preventing vibrations. You'll need a lot of DIY diffusion of the light; paper, yoghurt pots etc.
The optics are the easy bit!
Chris R
I'd forgotten we had that one! Perhaps it needs a link to the other FAQs in it.CarlW wrote: the FAQ at the top of the page, .
Yes there is a lot here, if you can find it.
The forum search facility isn't great, unfortunately (do read the text carefully) and Google have now stopped their site search
.Rik's personal list of links is useful :
http://www.janrik.net/RiksLinks.html
Chris R