A Panoramic Macro?

[Kevin Childress]

Something for fun ...

Ever heard of a panoramic macro photograph? I had not until I had the idea to try one recently. I shot this with my 85mm macro lens, which is a DX lens, so I'm dealing with a 1.5X crop right off the bat. This lens produces 1:1 reproduction maximum and of course I wanted to take advantage of that magnification. Problem was the abandoned cicada chrysalis is too large of a subject to fit the 1.5X image crop in a single frame. So a panoramic image seemed to the answer. This was probably the most challenging table-top project I've tackled so far, but it seemed to come off pretty well. 

The panoramic stitch consists of 15 panels (3 rows by 5 columns). Each panel consists of 5 focus-stacked frames - at the bottom is a screenshot of the focus-stacked frames that were used for the panoramic stitch. Although I cropped the stitch to a 3:2 aspect ratio, the cropped image was still huge so I had to re-size the image to 49 megapixels in order for Panoramio's server to accept the upload. I guess Panoramio's upload limit is still 50Mp/image?

These macro shots always reveal something fun and interesting in the detail. Here's the bonus round for this image ... Find the bug on the bug!!

[© Tom Cooper]

So I count a total of 75 exposures.  The thing about working at these extremes is that any flaw, anywhere, no matter how small, ends up exposed.  I saw a number of places where there appeared to be gaps in the focus stacking - areas where I would not expect the image to be out of focus, but it is anyway.  Still, the amount of detail is remarkable.  Oh, yes, there's a bug that reminds me of a termite near image center, to the lower left of the big bug's eye.

 

Tom C.

On Tuesday, September 9, 2014 8:53:59 AM UTC-5, Kevin Childress wrote:

[Kevin Childress]

Right on, Tom. I decided to take the focus stacking part of it pretty easy not knowing if I could actually pull off the panoramic bit. So I just shot 5 stacked frames instead of some ridiculously high number to see if I could stitch the stacked frames together. Either way your point is well taken. I even looked back through the individual frames to find "replacement" parts to brush into areas that were not real sharp. It turned out that what's blurry in my stacks were also blurry in my individual frames. I moved the lens (image sensor) linearly 4mm between each individual frame - apparently my f-stop wasn't great enough for that large of a linear step. 

Good find on the bug-on-the-bug! That's one tiny 'lil dude. Maybe some kind of mite? I wonder if its in my house somewhere ...  :)

[Kevin Childress]

Tom Cooper wrote:

I saw a number of places where there appeared to be gaps in the focus stacking - areas where I would not expect the image to be out of focus, but it is anyway. 

Oh, yes, one thing I forgot to mention ...

When I started shooting, I had the focus racked out to max magnification. And I had calculated the number of frames needed for the stack (5) based on the center row where the lens was exactly level. I noticed that "depth-of-focus" point seemed to change a bit on rows 1 and 3 where the lens was angled upward and downward. I never touched the focus ring after the initial setting although I noticed something was different as the lens angle changed. I'm not sure how the vertical lens angle complicated things in that area but is seemed to have some effect on the number of frames needed for a sharper stack ... if that makes any sense. 

[David Humphreys ( formerly Galatas )]

Awesome work , Kevin.
I like doing macros myself but I couldn't even contemplate taking on a project like this. How on earth did you keep the subject from moving during so many exposures ?

Big fleas have little fleas upon their backs to bite 'em. Little fleas have smaller fleas , and so ad infinitum.

EDIT :  I just came back to this after a night's sleep and realised my mistake :-)
Cicada chrysalis ( golden ) isn't the name of the species as I thought. You meant it's the exuvia of a Cicada , so of course it wouldn't move.
Chrysalis is normally used to mean the pupal stage of butterflies.

[© Tom Cooper]

Kevin wrote:

I'm not sure how the vertical lens angle complicated things in that area but is seemed to have some effect on the number of frames needed for a sharper stack ... if that makes any sense. 

I think I know what you are talking about, and it makes some sense to me.

The issue is that as the lens is angled, it becomes a different distance from the subject.  A simple way to demonstrate.  Point your finger directly at the center of your screen and just touch the screen.  Now point your finger at another part of the screen, without moving your arm at all (only pivot at the wrist).  Your finger is no longer touching the screen.  A rectilinear lens compensates for that variation in distance.  But as soon as you angle or tilt the lens, the subject is no longer parallel to the film, and the lens is farther from (or closer to) the subject.

If you want to get dizzy, start pricing shift lenses.  I don't think they even make them for macro work.

Tom

[Kevin Childress]

David Humphreys ( formerly Galatas ) wrote:

You meant it's the exuvia of a Cicada , so of course it wouldn't move. Chrysalis is normally used to mean the pupal stage of butterflies.

Awesome - thanks, Dave!! I knew chrysalis wasn't the right term but I had no idea of the exuvia phrase.  

[Kevin Childress]

Tom Cooper wrote:

The issue is that as the lens is angled, it becomes a different distance from the subject.  

Indeed. That makes perfect sense all around!