A lens to magnify tiny objects?

[smallfooties]

I have the Sigma 105mm at the moment and i would like to be able to take pictures of things really tiny and be able to magnify the object... I'm talking about things like blood cells etc to that effect... Or even a sand grain... Does this make sense?
What do i need to be able to do this?

Thanks kindly...

[Sobriquet]

I too have a sigma 105mm macro and it is a sharp lens, I like using it with and without extension tubes. You can get a set of fully automatic Kenko extension tubes or buy individual Canon ones. I have kenko for 1 reason, they don't have glass, so no issue with using a lesser brand, I have had them for quite a while (10 years) but think they cost less than $300 for the set. I often use just one but you can use all at once. I have had it set up so that the focusing distance was less than 1cm which didn't allow enough light. If you get close up filters you degrade your image a little, extension tubes don't. How they work is they reduce the minimum focusing distance so you can get closer and therefore your subject is bigger on the sensor or film.

Of course you lose depth of field but if your lens is like mine it has a tiny aperture and can down to f45, research circles of confusion and do your own test exposures, I don't go much below f22.

If you still can get closer enough you may need a bellows or a microscope attachment. All possible but macro 1:1 is enough for me.

:)

[smallfooties]

Hey Sobriquet!
Thanks for your reply!
So you think the extension tubes will be good?
I want to magnify it to really huge... i've seen shot where people take pictures of really small things...
So perhaps a microscope attachment like you said might be good... do you know how much it will cost to get a microscopic attachment for the lens?

[OzzieTraveller]

G'day all

Using your 105 + lots 'n lots of tubes [or extension bellows] certainly is one way of getting really-really close, BUT you will be so close that your filter ring will a) shadow the subject &/or b) actually touch the subject

Another thread here is the 'reversing-the-lens' bit
Years ago I did lots of real-real close up stuff via reversing my 24mm lens. As it was a retrofocus lens [most w/a lenses are], it always came into focus about 20mm from the subject, and the construction was such that lighting & shadows were never a problem
So by using 48mm of tubes on the 24mm lens would give 2x live size, but the thing with reversing a wide-angle lens was that it gave me an image of about 4x life size
Depth of Field at f22 was 1mm at best

Hope this helps a bit ...
Regards, Phil

[smallfooties]

Hi phil,
Thanks for the reply...
So 48mm of tubes on a 24mm lens? Can i use my 18-50mm lens? or does it only work with prime lens?
and the 48mm tubes are the kenko tubes? How do you reverse the lens? Is there an attachment i need to get?
Would these cost much? Thanks kindly.

[smallfooties]

Hi phil,
Thanks for the reply...
So 48mm of tubes on a 24mm lens? Can i use my 18-50mm lens? or does it only work with prime lens?
and the 48mm tubes are the kenko tubes? How do you reverse the lens? Is there an attachment i need to get?
Would these cost much? Thanks kindly.

[OzzieTraveller]

G'day fellas

Been thinking about this a bit more during the night ... :confused013
and also coming back to the original thread of "i would like to be able to take pictures of things really tiny and be able to magnify the object" etc etc

The long-established 'rule' when working close ups is
"when the extension = the focal length, you are working at 1:1 image size"
ie , 50mm of extension with a 50mm lens = life-size on the film

Today you need to remember the APS crop factor as well, the image size would now go to 1.5x life size

So ... with your 105 macro lens set to infinity. you will need 105mm of extension to achieve 1:1 ... tho the lens itself will extend at least half this distance, you only need to add the other half [via the ext'n tubes]

However, if you put your tubes together - 60mm all up - onto a wide-angle lens of say, 20mm - you will get 3x life size immediately (plus the crop factor)
The difficulty is that the front-of-the-lens distance to the subject now becomes so small that the lens is often touching the subject

You can use the 18-55 zoom lens in this manner, [I]but you cannot use the zoom during the process! Immediately you touch the zoom, you change the mm's of the lens, the extension ratio changes, the focus changes and your temper changes as well :cool:

Now to reversing the lens
Every lens MUST maintain a constant focussing distance from the bayonet mount to the sensor - you can zoom it however you want to change the 'front' bit, but the 'back' bit must always be constant. So when you reverse it, it always must have a certain distance between it and the focus point, ie: the subject

Thus [in film camera days] with a mechanical lens, it is possible to get an adaptor for bayonet to filter thread, reverse the lens, open it to about f8 for focussing, manually close it to f22 and take the photo.
Today's lenses are electronic, so you can't do this stopping down manually :(

I would suggest several things here ...
IF- you are serious about doing lots of this stuff, wander past your local 2nd-hand shops and pick up for $25-ish, any old film camera wide angle lens that looks in good nik. Doesn't matter who made it, as you're not going to be using it with the lens-to-camera bits connected. Make sure that it's got an Aperture ring, and that when you whiz the ring from max to min apertures, that the internals of the lens are opening & closing - you can see it happening
Then google 'lens reversing adaptors' [maybe AP Sponsor B&H might have 'em too] and look for an adaptor for your camera's bayonet to the wide-angle filter size ... eg "canon to 55mm" and grab one

If you can't get an adapter, you may have to consider making one from a plastic body cap and a filter step-up/step-down ring [of the w/a lens filter size] - saw out the centre of the cap keeping the bayonet bit, get the metal ring, and epoxy-glue the 2 bits together

keep asking Qs as needed, but in the meantime, hope this helps a bit ...
Regards, Phil

[ZedEx]

You're going to need a microscope is you seriously want to photography blood cells. Canon offers a 65mm 1-5x zoom for specialised macro work. Even this, set to 5x lifesize, can fill the viewfinder with a grain of rice. You're really going to need a microscope if you want to be doing cells, anything else is just going to lose sharpness and be unuseable anyway (pretty much anything to add onto or behind of a lens, will be detrimental to image quality)

[smallfooties]

thanks guys for the replies... thanks oztraveller for giving this more thought... really appreciate it...
i actually have a 35mm lens for my olympus OM1... would this work or it definitely has got to be in the 20mm range?
hmmm.... i've managed to get really old extension tubes for $40... i will have a play around with the lens i've got to see which one gives me the results i want. i've already played with the extension tubes on my siggy 105mm.... the magnification seems to only increase slightly... So as per your suggestions, i'll try it with my 18-55 and the 35mm.... i wanna get more serious with this form of photography.. as i think i'm better at this genre than any other.... kekeke....
So it's time for me to just focus on one genre and be good at it...
Thanks guys again for the help....
Oh are microscopes expensive??? like i would have to get a pretty good one don't i?
Oh and ZedEX, does nikon have a specialized macro lens like the canon one you mentioned?

[swifty]

I don't know how its done but I do know of a microscopy competition and the images in that comp are phenomenal!!!
Here's a link:
http://www.microscopyu.com/smallworld/gallery/

[smallfooties]

it's all very cool swifty!

[ncbuxton]

My scope and digital camera combination (lenses x2, x6.3, x10, x25 and x40 with x12.5 eyepieces costs upward of $25000!) This enables photomicroscopy of cells and some sub-cellular detail (nuclei, nucleoli etc).

[smallfooties]

:rolleyes:

[colinbm]

smallfootsies
Try this site for size
http://www.proscitech.com.au/cataloguex/online.asp?page=o7#OMDC140FL
This is the microscopy photography page.
They have microscopes & many other scientific stuff !
Cheers
Col

[smallfooties]

Oooooo Thanks Col!