Snowflake Rig

Have questions about the equipment used for macro- or micro- photography? Post those questions in this forum.

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DanielPBrown
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Snowflake Rig

Post by DanielPBrown »

Howdy all, this is my first post to this forum. I'm a professional fine art photographer. A popular subject of mine is snowflakes. I've been photographing them for about five years now. Here is a link to my snowflake gallery,
http://www.danbrownphotography.com/gall ... p?album=13
I started out using a Canon mpe65 lens and recently bought an Olympus 20mm f/2 macro. The 20mm lens allows me to photograph at 7X which is a little more than the 65mpe. The image quality seems better too. I would like to get a lens that would deliver the highest possible image quality and allow me to make large prints of the snowflakes. A magnification of 7X would be perfect. I use a full frame Canon.
A couple of options that I am considering are, Leica 25mm f/2 photar, or a Mitutoyo 5X EO M Plan HR Infinity-Corrected Objective. I believe the microscope objective would require a tube lens, would this impact the image quality/ resolution? I understand that I will have to focus blend to get the most resolution possible.
Any help would be appreciated.
Dan
Here is a snowflake shot with the OM 20 @ f/4

Image

ChrisR
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Post by ChrisR »

DON'T TELL HIM, LADS!!
At least not until he gives away a little of his technique!

Well ok, just mho: I'd go for
Nikon plan apo 4x NA0.2 160/0/17 objective, will push to more than 4x. The corners may go soft but your images are squarish.
Worth trying the 4x NA0.13, which I think covers better.
Then Nikon CF 10x 0.30 160/0/17 objective.

Better than that would need stitching. How long have you got before they melt? :shock:

No tube lenses required.

There are some threads here but mostly for less than 7x mag.
CHeck here:
http://www.markerink.org/WJM/HTML/microlen.htm

Having said that, do you actually get fine detail to resolve in snowflakes?
How big do you want to print?

rjlittlefield
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Post by rjlittlefield »

DanielPBrown, welcome aboard!

I'd like to hear about your technique also. Snowflakes are notoriously hard to handle but obviously you have it down cold (sorry!).

I assume you're talking about the Olympus 20 mm f/2 bellows macro lens, like HERE. That is an excellent lens, best used wide open.

The sharpness of high end macro lenses is generally limited by aperture -- wider is sharper.

Because of pupillary magnification factor, the Olympus 20 mm f/2 acts more like f/2.6 when used as intended in its "optimum range" of 4.2-16X. That's not as good as an f/2 without the PMF, but even so it's a bit wider than an NA 0.13 microscope objective, which would be equivalent to about f/3.1 at 4X. So, I doubt that you would get much better sharpness (if any) by switching to an NA 0.13 objective.

You could do substantially better, though, by switching to an NA 0.25 or 0.30 objective.

See HERE and the remainder of that thread for some recent comparisons of Olympus and Luminar macro lenses with a 10X NA 0.30 objective.

--Rik

mgoodm3
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Post by mgoodm3 »

The EO 5x APO, even with a tube lens, has significant corner fuzziness. I am geussing that some of the aberrations are corrected by the eyepiece, making it not particularly useful for a bellows.

mgoodm3
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Post by mgoodm3 »

The Oly 20/2 is better than the leica 25/2 - at least as far as the ones I own are. The Oly is a very good lens.

8x and above a good 10x objective is the way to go.

DanielPBrown
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Joined: Tue Feb 16, 2010 6:05 pm
Location: NH
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Post by DanielPBrown »

ChrisR wrote:DON'T TELL HIM, LADS!!
At least not until he gives away a little of his technique!

Well ok, just mho: I'd go for
Nikon plan apo 4x NA0.2 160/0/17 objective, will push to more than 4x. The corners may go soft but your images are squarish.
Worth trying the 4x NA0.13, which I think covers better.
Then Nikon CF 10x 0.30 160/0/17 objective.

Better than that would need stitching. How long have you got before they melt? :shock:

No tube lenses required.

There are some threads here but mostly for less than 7x mag.
CHeck here:
http://www.markerink.org/WJM/HTML/microlen.htm

Having said that, do you actually get fine detail to resolve in snowflakes?
How big do you want to print?
I think there is more more detail than I've captured, take a look,
Image
That is a 100% crop of the original image above. The original image was cropped and covers about 2.7mms. The crop covers about .38mms.
Currently I print as large as 12x12 inches. I've done one at 16x16 but that is pushing it. I would like to feel confident with 24x24 inches.
If it is cold enough I do have time to stitch. It really needs to be less than 25 Fahrenheit.
I did a little write up of my technique here,
http://www.danbrownphotography.com/blog/
Is the Nikon plan apo 4x still available new?
Thanks for the reply,
Dan
Last edited by DanielPBrown on Thu Feb 18, 2010 2:05 pm, edited 1 time in total.

DanielPBrown
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Post by DanielPBrown »

rjlittlefield wrote:DanielPBrown, welcome aboard!

I'd like to hear about your technique also. Snowflakes are notoriously hard to handle but obviously you have it down cold (sorry!).

I assume you're talking about the Olympus 20 mm f/2 bellows macro lens, like HERE. That is an excellent lens, best used wide open.

The sharpness of high end macro lenses is generally limited by aperture -- wider is sharper.

Because of pupillary magnification factor, the Olympus 20 mm f/2 acts more like f/2.6 when used as intended in its "optimum range" of 4.2-16X. That's not as good as an f/2 without the PMF, but even so it's a bit wider than an NA 0.13 microscope objective, which would be equivalent to about f/3.1 at 4X. So, I doubt that you would get much better sharpness (if any) by switching to an NA 0.13 objective.

You could do substantially better, though, by switching to an NA 0.25 or 0.30 objective.

See HERE and the remainder of that thread for some recent comparisons of Olympus and Luminar macro lenses with a 10X NA 0.30 objective.

--Rik
Yes, the OM 20 f/2 is the lens I have. I'll try it wide open next time. Thanks for the info, it reminds me why I like photography so much, there is always more to learn.
Dan

DanielPBrown
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Post by DanielPBrown »

mgoodm3 wrote:The Oly 20/2 is better than the leica 25/2 - at least as far as the ones I own are. The Oly is a very good lens.

8x and above a good 10x objective is the way to go.
I'm surprised the Leica falls behind the OM considering the price and that it is a Leica after all.

Dan

DaveW
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Post by DaveW »

I think you would get better apparent resolution if you used another background colour. If you could get a white snowflake on a black background it really would "pop". At the moment your background colour is tinting the white snowflake. Devising some form of dark-field illumination might help?

http://www.scientificamerican.com/slide ... hotography

There is a device for photographing snowflakes in Lefkowitz's Manual of Close-UP Photography if I remember correctly? But I don't think it uses dark field illumination.

These may be of interest:-

http://www.its.caltech.edu/~atomic/snow ... photo2.htm

http://snowflakebentley.com/

http://www.microscopy-uk.org.uk/mag/art ... ystal.html

There is a set-up for dark-field macro photography here:-

http://www.opconline.ca/ident/2009/Addi ... PGUIDE.pdf

DaveW

DanielPBrown
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Post by DanielPBrown »

Thanks Dave, two of those links are new to me.
Can anyone tell me where to find the Nikon objectives?
Thanks,
Dan

Planapo
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Location: Germany, in the United States of Europe

Post by Planapo »

Dan,
Welcome aboard! I really like your snowflake photographs!

As to suitable Nikon objectives, there are currently this M Plan and these two BDs for sale on eBay for rather moderate asking prices, and for the BDs you could put an even lower offer in:

ebay # 310201027068

ebay # 370336478446
ebay # 330405563178

Unless stated in the description, before buying a used objective, I 'd ask the seller, if the glass is in goood condition and thus the optical performance flawless. And note that as the BDs have a thread that is larger than the RMS, fitting a BD to a bellows is somewhat trickier.
But I am not perfectly sure if these objectives will cover your full frame sensor well, as most people around here use smaller sensors with objectives on bellows.

--Betty

DanielPBrown
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Post by DanielPBrown »

Planapo wrote:Dan,
Welcome aboard! I really like your snowflake photographs!
--Betty
Thanks Betty, and thanks for the links.
One question, will I be able to get 7X magnification on my full frame camera with the 10X objectives?
Dan

rjlittlefield
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Post by rjlittlefield »

DanielPBrown wrote:One question, will I be able to get 7X magnification on my full frame camera with the 10X objectives?
No.

Microscope objectives are designed to cover only the size of an eyepiece field, typically about 25 mm diameter. You would need 43 mm diameter to cover a 24 mm x 36 mm sensor at designed magnification. If you reduce the magnification by using less extension, then the field gets even smaller. At 7X, a 10X objective is liable to get fuzzy in the corners of even an APS-C sized sensor.

Using a low-NA objective, you can increase the extension to cover a larger sensor, but then the magnification increases also. To cover a 24 mm x 36 mm sensor with a high quality image at 7X, you would need an objective rated at about 7*(25/43) = 4X. Then the problem is to find a 4X objective that has an aperture significantly wider than a conventional macro lens. The Olympus 20 mm f/2 that you already own acts very much like an NA 0.15 objective. You can get slightly wider with a plan apochromat objective, but then I would worry about the tradeoffs of extending the objective beyond its design point, versus using a slightly smaller aperture in the middle of its optimum range.

--Rik

ChrisR
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Post by ChrisR »

Something for the weekend.
I need something 3mm - 5mm , flattish and detailed :-k
4x0.2, 4x0.13, 5x0.1, oly20f2, oly20f3.5, zeiss 25f1.4, macro nikkor 19f2.8

Place your bets.
(but I lied about the nikkor)

Planapo
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Location: Germany, in the United States of Europe

Post by Planapo »

Ahh, a lens collector! :wink:
What's the fast Zeiss, a CZJ Tevidon?
I need something 3mm - 5mm , flattish and detailed
You could use a wing of a butterfly or moth. I know Brits store their cash there :), but chances are you can also find such a wing in the attic.
Now we are waiting in curious anticipation. :D

--Betty

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