Joined: 28 Feb 2015
|Posted: Sun Aug 21, 2016 11:38 am Post subject: equipment recommendations
|I currently volunteer to help with photographing gems and minerals at our club. We would like to photograph minerals and specimens that the children collect on field trips, and photograph the mineral inclusions that are in the minerals that were collected by members of the club. This will help our club educate the children and the community during our shows. Please help with any recommendations, as they will be greatly appreciated by all the members.
Current equipment I have:
EOS Rebel SL1 EF-S 18-55mm
Equipment I purchased so far:
58m to 42m Step Down Ring Filter Adapter
52 to 42 Step Down Ring Filter Adapter
RMS female to M58x0.75 male thread adapter
RMS Thread to M42 Adapter for microscope objective cone
Our goal of the project is:
1.) Photograph minerals close up.
2.) Photograph minerals at 10X to show mineral inclusions.
Equipment currently looking to purchase that need recommendations:
micro lens for our Canon rebel SL1. This will be used to photograph minerals and specimens.
Extension Tubes Compatible Canon to maintain functionality for other tasks.
new Ninfinite objective being sold by reputable companies. Though will help in achieving our goal of 10X magnification of mineral inclusions.
Some questions we have:
What is the best way to set this up to achieve our goal of photographing mineral inclusions at 10x?
Which one is better, to use a telephoto lens or a micro lens with an Ninfinite objective?
Please help with any recommendations, as they will be greatly appreciated by all the members.
Joined: 14 Mar 2009
Location: Near London, UK
|Posted: Sun Aug 21, 2016 2:52 pm Post subject:
|Hmm, well, it would be easy to suggest a few thousand $ of equipment, which would need a permanent setup and a lot of hours to learn to use. You'd get museum quality images.
Probably not what you had in mind?
At the other end of the spectrum could be a USB "microscope" from China.
If you could indicate how far up the curve you're aiming, meaning budget really, I'm sure you'll get a variety of answers!
Joined: 14 Mar 2009
Location: Near London, UK
|Posted: Wed Aug 24, 2016 5:40 pm Post subject:
|You asked in another post - I've brought it back here:
Most of the answers are "it depends".
Q1) It depends how big you want the "print" to be.
For 1000 pixel wide web use, things are much less critical than big prints.
Around 1:1 could be a fair answer, though a lot less than 1mm if you're using the best of everything for the biggest prints.
Q2) there are two <$100 Raynox lenses you can use, on a couple of sets of cheap Chinese extension tubes. Search for Raynox in the FAQ section.
Those work with infinite (no N) microscope objectives. Their focal lengths are 125 and 208mm. (See the FAQ thread on How do I hook up a microscope objective to my camera".)
Then there's couple of Nikon objectives which aren't the ultimate, but are very good and will hold the budget down. See the FAQ post "Where Can I get Nikon objectives".
You could get the (very cheap) 4xBE, but one of the the 10x would be an obvious choice at least.
The 10x will work on the Raynox lenses to give you 6.25x and 10.4x.
A lens which is so useful it has to be mentioned in spite of its ticket price, is the Canon MP-E 65.
You'll find it brilliant from 1:1, tailing off just a bit at the 5:1 end.
For bigger subjects, The normal standard is a Macro lens, usually at about 90 - 105mm. Most will take you to 1:1 but some stop at 1:2.
Even old macro lenses were all at least "good". Nobody bothered to make a baddie. The current Tokina is also very good, and a lot le$$ than the Canon.
An advantage of the Canon 105mm(including I think the non IS version not shown in that review) is that they focus internally. That means you can put an objective on the front and use software to focus, to get your stack of images (within a limited range).
As soon as you start stacking, you'll be interested in automating it. You can do stacks manually on a special stage/drive , but it gets boring, especially if you have to "do another run".(Search the forum on Proxxon for up to about 10x)
The most frequently quoted machine is the Cognisys Stackshot. There aren't many others, but you can build something yourself if you have some knowledge of mechanics and can use a soldering iron. Search the net on Stackduino, for example. <$100 including hardware.
Q3) you don't really want a zoom, though some work ok at their long end. If you zoom shorter you get vignetting (cropped corners). Things like the current STM zooms focus internally too, so if anyone has a 18-135 or a 55-250, they'd be worth a try.
I think I've blown your budget, by the time you add some lighting (flash is easiest) and mechanical contraptions.
Yes those other methods I wrote about in your first reference, can cost a lot less and can work well. Nothing covers a very wide range well though, which is why the MP-E65 is so attractive.
If it's too much I can suggest some clunky manual options such as on old (eg) Nikon Micro 55mm straight then reversed, for down to about 2:1, then use the Raynoxes + 4x and 10x Nikon objectives for 2.5x, 4.16x, 6.25x and 10.4x.
You'd need a bunch of cheap tubes and adapter rings - ebay.
Oh - you'll need to line the conical adapter you have with black flocking, such as Protostar, or you get nasty internal reflections.
I've just looked at a couple of the other links you posted. Oh dear.
Teleconverters only work well if you have an excellent lens to put it on, and extension tubes often push a lens way outside what it was designed to do.
So you "get more magnification", but it's "empty". You may as well just crop and enlarge. For most purposes you don't run out of pixels.