wwp@yahoogroups.com:
Re: Sigma 4.5mm Fisheye Lens on Nikon D300 ( Panorama Sample made with 3 pictures ).
jean-guy lathuilière 2008-Feb-07 16:26:00
Hi Roberto !
Thanks for all these precise explanations and for links: it shall be
very useful for many of us !!!
This lens looks great ... and cheap.
Shall anyone try it with Canon EOS 5 D ?
Have a nice time on next week end during your camping days testing
this Sigma lens ( what about weather in Mexico
now compared with our cold european winter ??? )
Regards, Jean Guy
Le 6 f?vr. 08 ? 08:43, Roberto Gomez Torres a ?crit :
> Hello List,
>
> A few days ago I bought one Sigma 4.5mm Fisheye lens.
> Mainly to be able to create fast spherical panoramas with less
> pictures for
> stitching.
>
> Here I want to share with you my findings, a sample and files for
> you to
> download and play with them.
>
> 1) The price of the lens.
>
> I bought the lens on eBay where I found the best price after some
> weeks of
> research.
> The seller is located in Honk Kong an gave me a great service and
> help. Here
> you can find the link to the add on eBay and the price I paid :
>
> http://cgi.ebay.com/ws/eBayISAPI.dll?
> ViewItem&ssPageName=ADME:B:EOIBSAA:US:11&Item=360015291254
>
> 2) The Nodal point.
>
> I spent the last weekend finding the best point for panoramas made
> with this
> lens when using 3, 4 or 6 pictures.
> Using "Really Right Stuff" panorama equipment I calibrated the lens
> distance
> from the tripod for rotation.
>
> The method I used was pretty similar to the one found here ( by Dave
> Watts ):
>
> http://dgrin.smugmug.com/gallery/2114189/1/109263193
>
> The distance from the camera tripod mount to the point of rotation
> I am
> using for this lens is : 10.8 cm.
>
> 3) Diameter of each fisheye image.
>
> On my Nikon D300 the Sigma 4.5mm captures a circle image with a
> diameter of
> 2,280 pixels very close to the center of the camera sensor.
> Since the Nikon D300 is capable of taking pictures with a
> resolution of
> 4,288 x 2,848 is clear that a lot of pixels are wasted.
>
> 4) The Camera Settings.
>
> For this first sample I used the following setting on the Nikon D300:
>
> - Manual Mode on Camera.
> - Manual Mode on Lens.
> - Aperture F/8.
> - Exposure Time 1 Second.
> - Format RAW 14 bits at 4,288 x 2,848 pixels.
> - ISO 200.
> - Metering Center Weighted Average.
> - Color Space sRGB
>
> 5) Taking the Pictures.
>
> For this shot I used a Bogen table tripod, a small Novoflex Ball
> Head for
> Leveling, Panoramic Rotator, L-Bracket and Slide Rail made by
> "Really Right
> Stuff".
> Only took 3 pictures, each at 120? from the other.
> In order to discard any possible vibration or moving the tripod I
> shot the
> camera with a remote wireless camera shutter made by "Aputure".
> The camera was mounted in portrait mode ( something I liked a lot
> since for
> years I only took panoramic pictures in landscape mode ).
>
> 6) Converting the RAW Pictures.
>
> Since RAW pictures can not be processed within PTGui Pro and are
> very heavy
> for Internet download, I am included only JPEG version of the
> source files
> with this sample.
> First I converted the RAW pictures using Nikon Capture NX into TIF
> files
> keeping all the possible color information including ICC profile.
> Then with Photoshop CS2 the TIF files were converted to JPEG with
> the less
> compression possible ( Here I applied a value of 11 from the scale
> that goes
> from 0 to 12 ).
>
> 7) Stitching with PTGui Pro.
>
> Once the JPEG files were ready I imported them to PTGui Pro v.7.5
> Started with new values for the circle fisheye images with a 180?
> FOV, 4.5mm
> and made a crop for each image with a diameter of 2,280.
> Set in the Control Points section one vertical line for each image,
> auto
> create the normal control points and optimized the values.
> Deleted manually some wrong auto control points and ready.
>
> With my Setting PTGui Pro gave me the following values for my
> template:
>
> - Lens Type: Circular.
> - Focal Length: 4.473
> - Focal Multiplier: 1.5x
> - Horizontal Field of View: 182.3?
>
> The only processing I allowed for the Source Images within PTGui
> Pro was the
> Exposure Correction with only the "Optimize Vignetting" setting
> Enabled.
> After Stitching using PTGui and Blending with Smartblend the result
> Equirectangular files has a resolution of 4,504 x 2,252 pixels.
>
> That Equirectangular final image allows a maximum optimal cube face
> size of
> 1,434 pixels.
>
> 8) Downloading the Sample Files.
>
> I have uploaded to my web site a ZIP archive with the 3 pictures in
> JPEG
> format, the PTGui Pro project, the Equirectangular file and the
> QTVR Cubic
> Panorama for you to play with.
>
> The Panorama was taken at my small Home Office !
>
> Here is the link to the ZIP file ( 16.7 MB ):
>
> http://www.tiempo-digital.com/galeria/sigma_4_5_sample_01.zip
>
> 9) Viewing the Panorama Online.
>
> Here is the link to view it on your browser:
>
> http://www.tiempo-digital.com/galeria/fs-sigma_4_5_sample_01.html
>
> 10) To Do list.
>
> Tomorrow I will be making some tests taking 4 pictures per panorama
> and also
> will take some tilting the camera for 5? to 15? in order to obtain
> a better
> Zenith coverage.
> Next weekend I will go out for camping and will test this lens at the
> outdoors, mainly I want to see how it works under the sun and
> possible lens
> flares will show.
>
> Please feel free to make me any question.
> And would love to hear your impressions about this new lens !
>
> Hope some of you thinking on buying this lens could find the report
> useful.
>
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