The making of a chicken broiling claustropano

Please view the 360 x 180° panorama:

Cubic QTVR (1.3MB)

Flash (1.7MB)


Another different interpretation of the same scene (QT Player):


The shooting scene:


Today's special recipe;-)

Foreword: I shall write "shooting (one) image" at numerous instances in the folowing text. In fact you should understand that at every instance, shoot of many photos with different times of exposure (manual bracketing) of the same image was done in most of the occurences and the best suited used in the later process..

Camera: Canon EOS 5D

Lenses: Tokina 10-17-mm @ 12.5-mm f/22 alternatively Sigma 8-mm f4 @f/32

ISO 200, 400 or 800, exposure time from 2 up to 60 secondes according to illumination circumstances.

Auxiliary additional tungsten lighting was used on some occasions (i.e. always when the door of the oven was open).

Process step
Details
Remarks and "How I did it"
1

Find a suitable spot where to place the "nodal point" (Entrance pupil) of the lens.

Beware: This is a very difficult task. While it seems to be rather simple at first glance, a location that suits for shooting four of the images would not be possible for the last fifth one as something would unexpectedly be in the way (Murphy's law). The lens can be too big to fit in the restrained open volume, or the body itself seems to be oversized... Further more there is just a sufficient height to place the optical axis at an altitude that allow the camera shooting inside the oven in portrait mode. A dry run was performed about a week or so before the final shooting session. After many hours (!) of trial, I have finally found the place that is OK. The "nodal point" had to be located in a place which the dimensions are not more than 2 x 1 x 1 cm!

The main principles for the shooting scenario was developed after this trial. The means, tools and accessories were then designed and build and a subsequent dress rehearsal proved the soundness of the project...

2

Make a ring to put around the -main- lens.

To assure the correct positioning of the pivot with respect to the entrance pupil of the fisheye (five shots) and eventually to support the cantilevered weight of the lens itself.

I've made it as a square part from 9-mm thick PVC plate. A blind hole in the PVC helps to fit the sharp tip of the tiny post (next step) in a precise manner.

Note: The secondary lens (step #8, 11 and 12) was used under different and more favorable conditions: I was able to precisely place it without having to use a ring device.

3

Make a tiny post to position accurately the lens while shooting.

This is the pivot on which the ring shall rest with precise location by resting on the sharpened tip. Its axis must be vertically aligned with the entrance pupil (a.k.a. "nodal point") of the fisheye.

Metallic (it's in fact an 8" long steel tack). The dimension of the PVC ring was selected in a way to have the tiny post to fit well with both the main lens with its ring and with the secondary lens (without a ring).
4

Install the post at the location (pivot point #1) that has been determined on step #1.

It eventually also supports the cantilevered weight of the lens.

I have fixed it on the edge of the dripping-pan by means of a home made clamp. The clamp could be dismounted and remounted with ease and located with precision.
5

Have the roasted chicken (still on the broiling spit) inside the oven in the broiling configuration.

The chicken should be still hot, the oven and the camera can be cooled by the effect of an air fan placed on the side of the shooting scene. If the oven is too hot, the moisture in the air may condense on the cooler front lens glass surface. Condensation doesn't last for long however.

Prepare the camera support system. Install the cooling device in place (air fan).

Camera support: No tripod allowed in this private and hot place!

I have used two beans bags and some other stuff for this purpose. This is a very old trick used to support long tele-lenses during Safari photography for instance. See photos of illustrations.

6

Shoot (at pivot point #1) three photographs of the interior of the oven with the main lens.

These 3 images shall be the components of the first hemisphere of the panorama (i.e. inside of the oven toward the chicken and the back). With the "shaved" 10-17 mm Tokina I could have gotten away with two images only (12 mm of focal), each separated by about 90 degrees but I selected to shoot three images separated by about 45 degrees (**).

Make sure to cover about 200 degrees of HFOV that must include the entire entrance of the oven opening.

Thanks to Pentax (who originally designed the zoom fisheye lens). The VFOV being much more than 190° helps to get sufficient overlap at both Nadir and Zenith in spite of the smaller VFOV of the Sigma (cf steps 11 and 12).

7

Remove the tiny post.

To get a unobstructed foreground for the shooting of the next image: Put it aside.

Do not worry: the tiny post will be used again soon.

8

Shoot now one photograph from the outside of the oven toward the interior.

This image shall be used to simulate the reflection of everything inside the oven in an exact "optical manner" (after reversing it left to right BTW).

With the lens having the entrance pupil located at the top of the "reflected image of the tiny post" (i.e. pivot point #1'). #1' is symmetrical with #1 with respect to the mirror planar surface (i.e. the glass surface of the oven window).

The position of point #1' can be assured with a relaxed accuracy requirement (+/- 5 mm).

Comment:The full circular FOV is unfortunately limited at 178° (f/32)...

I have then used the Sigma 8 mm f4.0 as a secondary lens.

A thin plate of the adequate height was used here to support the weight of the cantilevered lens front.

Alternatively (from Point #1) the rear glass surface of the (closed) door window would have reflected this same (but "real") image under the following conditions:

  • if the camera could have been placed there (i.e. between the chicken and the oven's wall: impossible)
  • and if the camera and its support would not make obstruction in the reflected image and unfortunately hiding most of the chicken.

As this was obviously not possible, I decided to cheat a little;-)

9

Remove the roast chicken from the spit

And place the empty spit back in place. You may now eat the chicken as it will not play any further role;-) (*) As the main character of the play isn't further involved in the shooting, the rest of the sequence can fortunately be done at any time before or after the rest of the steps: We may now eat the chicken: french fries and a glass of Saint-Emilion red wine are recommanded. Have a dessert and Bon appétit;-)
10

Place the tiny post back at its place

Now ready to shoot the other hemisphere (i.e. the door of the oven as viewed from inside) with the secondary lens (Sigma 8 mm).

The reflection of the chicken (cf step 8) shall overlay this second hemisphere during post-processing. It's why the same secondary lens is being used in both case.

I have tried to use also the Tokina (two shots spaced by 90 degrees) and thus benefit from the much larger resolution, but the front of the lens almost touches the glass surface of the door of the oven. As a consequence of this very short distance of the rear of the door I could not avoid very large parallax errors: if the top and bottom were OK then the horizontal plane would have errors and vice-versa. Even with lot of effort I couldn't get satisfactory result: the tiny points pattern that is printed inside the door glass is terrible (impossible?) to tweak under Photoshop.

11

Place the camera inside the oven so the lens entrance pupil is resting on top of the tiny post and aiming straight outside

Then shoot one image from inside through the window:

  • Hide the camera and the camera support
  • Set the timer of the camera and trigger it
  • Close the oven's door and wait until the photo is shot

The FOV is unfortunately limited at 178° (f/32)...

This image shall allow to include the visible end of the spit and the support hub in the panorama by extraction from the right of the individual image, .

To hide the camera and the camera support (i.e. the beans bags) I have used black crêpe paper. Therefore almost no reflection is visible in the door glass. The -faintly visible- lens round front remaining unhidden part shall be "overwhelmed" by the chicken strongly lit reflected image further in the process.

12

Remove the broiling spit and the frame that supports the spit as well

Then shoot another image from inside through the window:

  • Hide the camera and the camera support
  • Set the timer of the camera and trigger it
  • Close the oven's door and wait until the photo is shot

Comment: The FOV is unfortunately limited at 178° (f/32)...

This image allows having a clean background extracted from the left of the individual image i.e. without the unwanted "bowed" support frame rod (***) to complement the other part from the previous step. An artificial part (copied and pasted from another place) shall later be inserted to replace the absent metallic frame rod part.

The rod of the metallic frame (which supports the broiling spit itself) is so very near the front of the front glass surface of the lens, that parallax effect produces an unacceptable apparent bending on the rod. Please note that I am talking about parallax affecting a single image and (possibly) not affecting the stitching of two images (read the special complementary page that describes this topic).

13

Stitching of the panorama

Use the images from step 6 and 11 (or alternatively step 12) to output the primary panorama. I have used PTGui. Please note that two different lenses are used simultaneously: I have selected the highest output resolution (i.e. permitted by the Tokina lens) and therefore over-sampled the other part.
14

The rest of the recipe

Make and edit the panorama...etc.

Write the "How to".

I have used the supplementary images (including those with different exposure) as needed:
  • After conversion to equirectangular projection of every new image by using the corresponding PTGui parameters for the equivalent primary image, I edited the panorama under Photoshop.
  • The output hemisphere containing the door and it's window was partly overlaid with reflected view (cf step 8), etc.
  • Up to 8 layers were used at the same time. Not all being simultaneously activated though;-)
  • I often used PTEditor and or CubicConverter as complementary means for images / layer edition in conjunction with Photoshop CS3.

Some illustrations:

A- The tiny post B- The collar around the lens

Pivot point #1

C- Shooting interior

Pivot point #1

D- Shooting "fake exterior" i.e. interior view

Pivot point #1'

E- Ready to shoot toward the door and through the window

Pivot point #1

(The frame rod is removed here)

F- Shooting toward the window

Pivot point #1

(principle)

Click on images to enlarge

Lessons learned from the making:

This has unexpectedly proven to be probably the toughest panographic endeavor that I have ever undertaken.

Careful preparation, dry runs and many hours of post processing were the means to meet the expectation... this is just as usual but on a larger scale.


Conclusions:

I did not anticipate the extent of the work that has finally been needed to get IMO a satisfactory result but I am glad to have gone trough it.

I had prepared the final shooting session with a trial to define and make the necessary tools and accessories, then I have performed a dress rehearsal to check that the photos would possibly be adequate.

Even so, when the real shooting was done in the frame of WWP "Sustenance", I had to admit that much more photoshop tweaking than foreseen would be needed. The panorama was not mature at the end time of submission. I did not give up. I have had to invent new ways (at least for me) to overcome new hurdles. It subsequently took even more time and in fine the panorama makes itself as the imperative "best of 2007"....

To re-make it again (if needed) would be much simpler and fast thanks to experience. That's what I have tried to report in this article.

I sincerely hope you have enjoyed reading it. I also whish you shall share the fun and excitement that I felt throughout the project.

Michel Thoby

Revised: 6 December 2007