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PostPosted: Thu Oct 09, 2008 10:17 am 
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I currently have Canon EOS 450D/XSi with the kit lens (18-55mm), and an older Bogen tripod with 3D head. My first panorama stitched in APP worked well.

I'm going to upgrade lens before upgrading camera. What I would like to know is whether APP would work better with rectilinear wide angle lenses, or with a fisheye lens. Or does it not really make any difference?

A couple decades ago when I worked with 35mm film (I still have the Nikon FE-2, FM-2, Nikkor 20mm f/2.8, 35mm f/1.4) I favored rectilinear because I was just working in that small range for wide angle. Geometric modifications were all but impossible (I had limited access to printing and was doing mostly slides via commercial E6 processing). But with the power of digital processing, things change. Photos shot on one lens type could be converted to look like the other.

I'm not looking for a lens so wide to reduce the number of shots I need to take. I have 4 memory cards (2 2G, 2 4G) and lots of computer file space (8.4 TB). But I would like to keep number of shots within reason (e.g. 360 shots at 1 degree times a few rows with a telephoto is out of reason). With APP it seems I don't really need to a super wide angle, although the cheaper tripod head I have now makes multi-row panos hard to do, so at least wide enough to avoid multi-row in most cases would be desired.

Good sharp quality is more important and I believe a fixed focal length lens still achieves that better than a zoom. I'll use the kit lens for casual shooting. I'll be doing landscape, cityscape, and indoor panos. I also want to do some night time lightning filled panos, so something fairly wide would make those easier to do under the pressure of storm activity.

Do you have a suggestion for a Canon or premium after market brand lens? At this point I don't know if a later upgrade of the camera would be a 50D or 5DmkII, so it might make sense to give 2 suggestions if they would differ for APS-C vs. full-frame.


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PostPosted: Thu Oct 09, 2008 10:28 am 
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I'm about to order the fisheye Tokina 10-17 ; it seems to be a very good lens for full-spherical panos (12 pictures, 6@-30°, 6@+30°), but also for wide angle shots.

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Canon 20D + 17-40/f4 L USM + 70-200/f4 L USM + 50/f1.4 USM
Merlin/Orion panohead + Papywizard on Nokia N800 and HP TC-1100


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PostPosted: Thu Oct 09, 2008 1:15 pm 
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Hi Phil!

Preferring quality before comfort i use to make spheres with a 20mm Nikon on my Canon 20D.
The Nikon 3,5/20mm you can get on ebay for around 250.-€ and it is a VERY fine lens: razorsharp, without any CAs and distortions.
I had a 2,8/20mm before and found it having slight distortions.
In spite of upgrading to a fullframe with a SLRE prime-lens you have a lens constructed just therefore.

The big advantage is: i can take a part of the sphere for a rectangular wide angle picture and still have a resolution that uses to be remarkably higher than the resolution of average DSLRs in one shot.

I sometimes use a 10,5mm Nikon fisheye for spheres - but there are always CAs and the resolution and overall-sharpness is not good enough to get cutouts to make real good rectangulars out of them.

So i really suggest a good prime-lens and take the lesser comfort of making more shots for a sphere. With the 20mm on 1,6 crop i usually shoot around 50 pictures with 30% overlap for a sphere - which allows stitching without any problem and, as i said, taking parts of the sphere as rectangular cutouts with good planar-projection.
As i also said: the prime SLR lenses work perfectly on a fullframe DSLR like the 1DsMkIII or a 5D MkII (wich i tested on Tuesday).

I use an adapter-ring from Novoflex to mount the Nikon-lenses on the Canon. For panorama shooting and especially for spheres you wouldn´t use any kind of automatic anyway . . .

You wouldn´t find lenses of comparable quality nowhere at the price of an "old" manual Nikon prime! They´re great lenses. I use to use a 1.8/85mm Nikon also with great pleasure - it´s about 35 years old . . and one of the few REALLY sharp lenses i came by over the years.

best, Klaus

have a look of using the 1,8/85mm for stitching here: (the oversight is a spherical projection - that causes the distortion. It has about 160 deg. - that´s too muchg for planprojection:)

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Last edited by klausesser on Thu Oct 09, 2008 1:17 pm, edited 1 time in total.

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PostPosted: Thu Oct 09, 2008 4:01 pm 
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Phil Howard wrote:
I currently have Canon EOS 450D/XSi with the kit lens (18-55mm), and an older Bogen tripod with 3D head. My first panorama stitched in APP worked well.

I'm going to upgrade lens before upgrading camera. What I would like to know is whether APP would work better with rectilinear wide angle lenses, or with a fisheye lens. Or does it not really make any difference?

I'll be doing landscape, cityscape, and indoor panos. I also want to do some night time lightning filled panos, so something fairly wide would make those easier to do under the pressure of storm activity.

Do you have a suggestion for a Canon or premium after market brand lens? At this point I don't know if a later upgrade of the camera would be a 50D or 5DmkII, so it might make sense to give 2 suggestions if they would differ for APS-C vs. full-frame.

My thoughts:

1) You cannot 'have it all' with one lens. There is no single lens that's ideal for every type of pano. And you certainly cannot achieve all you say you wish to do with just shooting a single row.

2) Landscape partial panos are probably best shot with a rectilinear lens, the focal length chosen depends on how many images you are willing to shoot and the final resolution you wish to have. So use whatever lens you like. If you want very high res. and this requires a lot of images (more than 20-30?) consider using a motorised pano head.

3) Indoor 360x180s are probably best shot with a circular or fullframe FE.

4) Busy 360x180 citiscapes are definitely best shot with a circular FE lens - the fewer shots the better.

5) Perhaps it's time to replace that old tripod - the 3D head will just get in the way.

6) Unless you plan to stick to partial panos of distant landscapes using non-FE lenses you are going to need a proper pano head - I suggest a Nodal Ninja 5 which will accommodate most lenses and bodies you are likely to use, the new models with the RD-8 and RD-12 rotators allow you to change no. of click stops 'on the fly'. If awash with cash look at the 360Precision Adjuste head.

7) Consider whether you will be producing panos solely for on-line display or whether you'll also wish to produce large prints - the resolution required for large prints is usually rather higher than that neeedd for even fullscreen display on-line.

Unless you are certain you will upgrade to a fullframe sensor body I suggest you focus on lenses best suited to cropped sensor bodies. Should you upgrade to a fullframe body you'll probably be able to sell your cropped sensor lenses for close to what you pay for them

Suggestions for Canon cropped sensor bodies:

Circular FE - The Sigma 8mm f3.5 (4-around+Z+N)

Fullframe FE - the Sigma 10mm or Tokina 10-17mm FE. (6-around+Z+N)

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Many different Nodal Ninja and Agnos pano heads. Merlin/Panogear mount with Papywizard on Nokia Internet tablets.
Nikon D5100 and D40, Sigma 8mm f3.5 FE, Nikon 10.5mm FE, 35mm, 50mm, 18-55mm, 70-210mm. Promote control.


Last edited by mediavets on Thu Oct 09, 2008 4:04 pm, edited 1 time in total.

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PostPosted: Thu Oct 09, 2008 5:25 pm 
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mediavets wrote:
Suggestions for Canon cropped sensor bodies:
Circular FE - The Sigma 8mm f3.5 (4-around+Z+N)
Fullframe FE - the Sigma 10mm or Tokina 10-17mm FE. (6-around+Z+N)

Ii tried both of them: lots of CA and straylight! The Nikon 10,5mm also produces CA - but obviously less.

Again my advice: a Nikon 10,5mm FE for quick shooting, a fine 20mm or 35mm prime for superb quality advanced shooting.

The Nikon 10,5mm seems to be a kind of standard amongst pano-sphere photographers - for good reasons.

But i didn´t follow newest developements from other producers of fe-lenses - maybe they´re got better.

bst, Klaus

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PostPosted: Thu Oct 09, 2008 6:15 pm 
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Klaus,

You would recommend the Nikkor 10.5mm fullframe FE on a Canon 450D?

I guess you could use an adapter but would you not lose metering (and AF not that that matters)

Many pano shooters on Canon cropped senor cameras seem very happy with the Tokina 10-17mm fullframe FE which is available in a Canon fit.

Not sure it would be much good for sphericals in busy cityscapes?

So IMO the best compromise - if only choosing one lens - for the range of scenes he wishes to shoot is the Sigma 8mm f3.5 FE.

I have both the Nikkor 10.5mm and Sigma 8mm f3.5 FEs for Nikon DX and if I could only keep one I'd keep the Sigma. I think it's 'good enough' for 360x180 for fullscreen display but I'm not a pro photographer so probably have less discernment WRT image quality than you do.

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Many different Nodal Ninja and Agnos pano heads. Merlin/Panogear mount with Papywizard on Nokia Internet tablets.
Nikon D5100 and D40, Sigma 8mm f3.5 FE, Nikon 10.5mm FE, 35mm, 50mm, 18-55mm, 70-210mm. Promote control.


Last edited by mediavets on Thu Oct 09, 2008 6:18 pm, edited 1 time in total.

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PostPosted: Thu Oct 09, 2008 6:28 pm 
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According to users, the Tokina is very close to the Nikkor 10,5 for quality (and defaults, like CA), but you have to use a smaller aperture. This is not a problem, as you shoot with tripod, and often need a decent dof...

The Tokina is a zoom, so you can shoot from 12 pictures, to 30 (don't know exactly how many @17 mm), depending of the final resolution you want.

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Canon 20D + 17-40/f4 L USM + 70-200/f4 L USM + 50/f1.4 USM
Merlin/Orion panohead + Papywizard on Nokia N800 and HP TC-1100


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PostPosted: Thu Oct 09, 2008 7:16 pm 
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Hi Andrew, hi Frédéric!

"You would recommend the Nikkor 10.5mm fullframe FE on a Canon 450D?"

Yes - i do. As i said, i compared it to Sigma and Tokina on a Canon 20D. In my eyes their capabilities to use highres cutouts are limited - not only naturally in final resolution but due to CA and stry light.

"The Tokina is a zoom, so you can shoot from 12 pictures, to 30 (don't know exactly how many @17 mm), depending of the final resolution you want."

Yes - that´s an advantage in deed!

best, Klaus

besides: Frédéric: In an hour or so i´ll send you a mail with an Aircable issue.

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PostPosted: Thu Oct 09, 2008 8:22 pm 
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klausesser wrote:
"You would recommend the Nikkor 10.5mm fullframe FE on a Canon 450D?"

Yes - i do. As i said, i compared it to Sigma and Tokina on a Canon 20D. In my eyes their capabilities to use highres cutouts are limited - not only naturally in final resolution but due to CA and stry light.

best, Klaus

OK I missed your point about using crops from single defished FE images as super wide angle shots. At least I think that's what you are talking about? Perhaps you are talking about cropping from stitched FE images?

Sigma 10-20mm rectilinear WA is said to be pretty good for WA single images and would compliment a FE well IMO - I certainly plan to get one.

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Many different Nodal Ninja and Agnos pano heads. Merlin/Panogear mount with Papywizard on Nokia Internet tablets.
Nikon D5100 and D40, Sigma 8mm f3.5 FE, Nikon 10.5mm FE, 35mm, 50mm, 18-55mm, 70-210mm. Promote control.


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PostPosted: Thu Oct 09, 2008 8:59 pm 
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Hi Andrew!

Using crops from spheres would mean high-rez spheres. I did it from fe-shot spheres and it didn´t do good enough.
For that reason - to be able to select rect. images out of spheres - i do those spheres with the 20mm.

best, Klaus

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PostPosted: Thu Oct 09, 2008 9:01 pm 
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Thanks for all the input. I'll be slowly digesting it as I figure out what I might get. Fall colors are starting to show in trees, so I may just do with what I have for now to get some of that.

In the mean time I'll add some more information.

I don't expect to do a lot of 360x180 sphericals, but there might be some. I've never done that before, so I don't know how well that appeals to me. Maybe it would be good for a lot of church sanctuary photos.

The number of photos to take for a scene will, of course, depend on various factors. If I am going to insert a subject into each photo to make it/them appear multiple times in the pano, I have to choose my shooting carefully. Otherwise I don't mind taking a lot of shots at 5 degrees, even if I have a very wide angle lens.

My biggest concern right now is rectilinear vs. fisheye as it applies to non-spherical lenses. Should I get a rectilinear or a fisheye. The concern with this question is which will retain the best quality when APP works with it.

And what focal length if fisheye. I was considering a 20mm f/2.8 if rectilinear.

My first inclination was to stay with rectilinear. But anything more than near 180 degrees can't even be converted to a true rectilinear, and near 180 it would get rather radical. A full 360 pano is round on a flattened display/print/etc. So it's really effectively a fisheye. So APP would really be adjusting the geometry from rectilinear to fisheye-like. And I can see that in my first pano. So I'm thinking a fisheye lens would be better for APP.

But I don't want to get too wide, either. I don't want it to be so wide that only 2 to 4 shots gets everything, as that would mean lower final resolution. But I do need to account for the cropped sensor, too. I was looking at the Canon 15mm fisheye.

And fisheye lenses do have lower prices compared to equivalent focal length rectilinear. I'm hoping that is because a fisheye design is inherintly less costly than a rectilinear design, and doesn't really reflect a lower quality in terms of resolution, sharpness, aberration corrections, etc.

I expect to also get other lenses. Pano is not my only interest. My other interest is macro. If I get a macro that can also do infinite focus I can use that as a sharp normal for many-shot panos, too. But I like the Canon 65mm (no infinity focus). And, if I can find an adaptor to fit the Canon camera that can mount either a Nikon mount lens, or a reversed wide angle lens (flange on one end and 62mm filter screw mount on the other for my Nikkor 20mm f/2.8), I might do that.

Yes, the cheap 3D head I have now is a limitation. It has marks, not detents or clicks, every 15 degrees, only for rotating horizontally. I can set a tilt up or down, but there are no marks there unless I scratch some on. I was planning on calibrating it to at least as close to perfectly horizontal as I can, and get a bubble level since some locations are likely uneven for standing on, anyway (so I'd need to level up with the tripod leg adjustments). It is a Bogen tripod from around 1984, which does support interchangeable heads. But I don't know what could be put on it today.






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PostPosted: Thu Oct 09, 2008 9:26 pm 
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Hi Phil!

If i got you right you want to do wide angle pictures of high resolution rep. big size?

If that´s the case a fe would be the wrong choice.

You definitely need a nodal head - with that you can use your existing lenses for making highres/big rectangular wide angle pictures. If your motivs allow multi-exposure stitching.

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PostPosted: Thu Oct 09, 2008 9:35 pm 
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This is only a guess, but I suspect that a good fisheye will have less distortion than a good rectilinear at near the same focal length. The reason is that the rectilinear lens introduces distortion to make the image rectangular.

Note that if you use an extreeme WA (eg Sigma 12-24 on an EOS 5D) people at the edges of a group shot will look fatter...


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PostPosted: Thu Oct 09, 2008 10:38 pm 
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hankkarl wrote:
This is only a guess, but I suspect that a good fisheye will have less distortion than a good rectilinear at near the same focal length. The reason is that the rectilinear lens introduces distortion to make the image rectangular.

Hi Hank!

What´s making you think so :cool: ? Besides: there´s no rectangular lens with the focal length of a fe!

best, Klaus

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PostPosted: Thu Oct 09, 2008 11:26 pm 
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If you can remove that 3-way head - leaving a 3/8 (or 1/4) screw - then you can attach most makes of pano head and then when shooting 360x180 the control 'levers' of the 3-way head won't be showing at the nadir.

If you plan to shoot any pano with subjects closer than 100 meters you need to get a pano head to avoid parallax errors which will ruin your stitch.

Unless you mount the camera in portrait orientation your VFOV is going to be rather small requiring more rows.

Do you plan to shoot any panos that will show full 360 degrees horizontally?

I'm still not clear whether you wish to print your panos or to display them on-line?

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Many different Nodal Ninja and Agnos pano heads. Merlin/Panogear mount with Papywizard on Nokia Internet tablets.
Nikon D5100 and D40, Sigma 8mm f3.5 FE, Nikon 10.5mm FE, 35mm, 50mm, 18-55mm, 70-210mm. Promote control.


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PostPosted: Fri Oct 10, 2008 12:01 am 
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klausesser wrote:
hankkarl wrote:
This is only a guess, but I suspect that a good fisheye will have less distortion than a good rectilinear at near the same focal length. The reason is that the rectilinear lens introduces distortion to make the image rectangular.

Hi Hank!

What´s making you think so :cool: ? Besides: there´s no rectangular lens with the focal length of a fe!

best, Klaus

Theory? A regular, simple lens throws an image circle which looks like a FE. The Rectilinear lens has to distort the image. See http://photo.net/learn/fisheye/ -- it discusses software, but the same holds true for optical correction.


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PostPosted: Fri Oct 10, 2008 4:45 am 
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More info:

I don't know how easy it is remove and replace the head that is there now. It should be possible because alternate heads were available for that tripod. I just don't know what kind of mount this head is connected on. Sounds like a project I should do soon.

I suspect many panos I do will have at least parts within 100m. That is a goal, to get a better head to make such adjustments with. But I need to try some things out with the one I have. Maybe I can twist it around a bit and get it into a better position to center the lens node. And maybe that will work with a vertical orientation. I'll need to do more experimenting with it.

I'm very much interested in 360 degree panos. I just tried another one real quick earlier today when my nephew came up with a funny idea. The funny part is in the center, but I did it as a 360 (24 shots at 15 degrees).

At the present time I have no plans to do any printing. It would all be for computer display, some online, some private.






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PostPosted: Fri Oct 10, 2008 4:47 am 
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Oh, in the previous picture, that's one person in 2 different shots. He doesn't have a twin. But now we can kid him about having killed his own twin :D


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PostPosted: Fri Oct 10, 2008 7:28 am 
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klausesser wrote:
I use an adapter-ring from Novoflex to mount the Nikon-lenses on the Canon. For panorama shooting and especially for spheres you wouldn´t use any kind of automatic anyway

A quick look at B&H Photo web site, they have Novoflex adapters only to mount on four-thirds system cameras. Is there some other adapter to go from Nikon lens to Canon EOS camera? Would this work for Nikkor AI-S lenses?

B&H does have a Bower adapter to go from Canon FD lens to Canon EOS camera. But this has an optical 1.25x conversion lens, which I guess is because there is no way to position the FD lens with respect to the EOS mounting flange to be at the correct distance from the sensor. Would a Nikon lens not have this problem? Or is that adapter of yours one with some optical conversion involved?

I have these Nikkor lenses: 20mm f/2.8, 35mm f/1.4, 55mm f/2.8 macro (and 3 extension tubes), 135mm f/2.0. I also have these zooms: 35-135mm f/3.5, 100-300mm f/5.6. If there is a way to adapt them to mount correctly on my Canon EOS 450D, that would be great. I would be less interested in an adapter with optical conversion. But an adapter with mount extension would at least still be usable for macro photography. All that was for when I did stuff with film (mostly E6 and B&W) on Nikon FM-2 and FE-2. I just elected to go with Canon for digital because it seemed to be a better featured camera for the way I deal with it, and was overall cheaper to make the initial jump to digital.


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PostPosted: Fri Oct 10, 2008 9:45 am 
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Phil,

AFAIK you would need a Nikon D200, D300, D700 or D3 to have your old Nikkor AI and AIS lenses work correctly with a digital body.

Perhaps you should have opted for a used D200 rather than the Canon 450D if you wished to make some use of your collection of lenses.

OTOH maybe it's time to sell off all your old film stuff and use that towards more gear for your Canon digital setup. 450D is a fine camera for pano shooting.

Lowest cost useful pano head is the Panosaurus.

But I'd recommend you consider the Nodal Ninja 3 or Nodal Ninja 5 instead.

You could mount any pano head on top of your 3-way.

I suggest you buy a pano head before anything else and get started with your 18-55 kit lens before deciding whther you want to splash out on other lens for panos. You are really making life difficult for yourself and wasting your time trying to shoot panos without a pano head.

If you live in the USA you can't really go wrong with the NN3/5 since they offer a 30-day money back guarantee and their customer service is top notch:
http://www.nodalninja.com/returns.html

I think the new models with the new RD-8 and RD-12 rotators look very nice because of the convenience of being able to change the no. of click stops 'on the fly' but I'm happy with my NN5L which uses detente rings.

Once you get started you will find that many of your (other) questions will answer themselves, there's nothing like hands-on to get a grasp of what pano shooting is all about. At least that was my experience.

If as you say you plan to shoot panos for on-line display then I think you would find a FE lens useful - greeater scene coverage with fewer shots with quite enough res. and image quality for 360x180 fullscreen display and I think you would be quite saitisfied with either the Sigma 8mm f3.5 FE or the Tokina 10-17mm FE - but get started with that kit lens! You'll need more shots to cover a scene but at least you will be on your way without a big investment other than buying a pano head.

You will find Pano2VR useful to get your stitched panos into a format - QT or Flash - to upload to the Web.

If you want some FE image sets to play with you'll find some here:
http://www.three60views.org.uk
http://www.agnos.com/samples.htm?v_lingua=ENG&v_iss_web=0000000008093008501585879651&v_menu_lista=MSXDX-MENSX-MSD03-M0302
http://www.360precision.com/360/index.cfm?precision=products.camlensinfolist

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Andrew Stephens
Many different Nodal Ninja and Agnos pano heads. Merlin/Panogear mount with Papywizard on Nokia Internet tablets.
Nikon D5100 and D40, Sigma 8mm f3.5 FE, Nikon 10.5mm FE, 35mm, 50mm, 18-55mm, 70-210mm. Promote control.


Last edited by mediavets on Fri Oct 10, 2008 11:26 am, edited 1 time in total.

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PostPosted: Fri Oct 10, 2008 12:57 pm 
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klausesser wrote:
Besides: there´s no rectangular lens with the focal length of a fe!

Hmmm...
- FF (aka 24 x 36 mm) : Nikon 14-24mm F2.8 AF-S rectilinear / several 16 mm Nikkor fisheyes
- APSC: Sigma 10-20 mm rectilinear zoom / Nikon 10.5 mm fisheye
- 4/3: Olympus 7-14 mm zoom and Olympus 8 mm rectilinear / Olympus 8 mm fisheye.

What should be take into account is the pixels amount per spherical surface unit next to the center and near the corners of the source images but this is very difficult to grasp:
- next to the image center fisheye image size is larger than rectilinear image size (much more pixels per angular unit - just compare images to see what I mean)
- next to the corners very wide rectilinear images use much more pixels than they use for the center (3 or 4 times!) so that the pixel defects are "compressed on the spherical image" (less visible, that is)
- next to the corners, fisheyes images are very distorted (not isomorphous, very compressed along the radius direction and very elongated in the perpendicular direction!)

As the corners are more than often not used (especially the fisheye image corners), the above considerations probably explain why I never found any serious attempt to ponder pros and cons of each lens types for spherical panos (where image quality should nor vary from place to place - this is often acceptable for ordinary images.) There are many other reasons that make practical comparisons difficult, for example the size of the .mov file being a more meaningful an drastic image quality limitation and micro-contrast issues (in my opinion how much sharpening to use and when to sharpen are as important subjects as the used lens IQ but this is never debated !)

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PostPosted: Fri Oct 10, 2008 2:56 pm 
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Hi GURL,

You forgot the FF Sigma 12-24 EX rectilinear. and the Canon 16-35 f/2.8 and its Nikon, etc equivalents. And canon has a 14mm f/2.8 Rectilinear lens (and 15mm FE).

And if you want to stay with Canon lenses, the widest Rectilinear is 14mm and widest FE is 15mm in currently available lenses. (I count the 10-22 as having an effective focal length of 16mm because its an AF-S and is only used on APS-C bodies.) You have to go to Sigma or Peleng for the 8mm fisheye, or Nikon for the 10.5

Not sure what you mean why you never found any serious attempt to ponder ... lens types for spherical panos. Do you mean you like FE lenses because the center is better than on Rectilinear lenses, and is more important?

Sharpening gives you a chance to correct mistakes, etc. The lens is critical--you can add accutance (ie a sort of contrast) but not resolution (the sharpness of features as opposed to the contrast of the feature and background)

You cannot remove blur, you can only fool the eye into thinking it is less than it really is. So sharpening and other post processing are things we all try, try and try again (for the cost of our time) while lens resolution and contrast are something we cannot improve except by buying a new lens (or calibrating the lens)


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PostPosted: Fri Oct 10, 2008 5:18 pm 
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My understanding of the optics of lenses tells me this about WA lenses. A horizontal line on the flat focal plan corresponds to a horizontal line on the subject when the lens is perfectly horizontal in both FE and RL lenses. That line at the subject is straight with with a perfect RL lens, but curved around with a perfect FE lens.

In a scenario with 8 shots to make 360 degrees, at 45 degree steps, using a RL lens, the subject is formed with 8 segments of straight horizontal lines. The end result is a big octagonal shape all the way around if the shots are stitched together with no geometric adjustments. This would be seen as distortion when viewing the panorama result because 8 parts of the picture would be closer while 8 other parts would further away.

In the same scenario, but with a FE lens, the subject is formed with 8 segments of curved horizontal lines. The end result is a big circle all the way around if the shots are stitched together with no geometric adjustments.

In order for a pano to have an equal horizontal distance in the resulting picture for each horizontal distance in the subject, the line needs to be a curved one. This is what you would get if you made 7200 shots around 360 degrees at 0.05 degree steps, and used just 1 vertical column of pixels from each shot to form a 7200 pixel wide pano.

That is why it seems to me that a FE lens would involve less geometric adjustment than a RL lens. With no geometric adjustment, the pixel resolution would remain uniform across the pano. With a RL lens, there would be geometric adjustments to make those (octagonal with 8 shots) joined straight lines into a perfect circle. That would result in alternating variations of pixel resolution uniformity.

That is one reason my thought (before the first post in this topic) was to favor the FE lens.

A particularly wide lens, whether FE or RL, would not be needed for digital processing because it is cheap to take many shots. With film, producing a pano from multiple shots was a huge amount of work, as well as a great expense of film. It was usually more convenient to just make one shot with as wide a lens as possible. And if you needed high resolution, you did it on large format.

The advantage of a wider lens now (in the digital age) seems to be in avoiding multiple rows for non-spherical results. Just how convenient that is depends on the quality of the pano head as well as the available time. Shooting 5 rows of 72 shots around (360 total shots) takes more time compared to shooting 1 row of 24 shots. And if you are also doing manual exposure bracketing, that can take a lot of time.

So it can be a balance between time (tends to favor the wider lens and fewer shots) and resolution (tends to favor the less wide lens and more shots).

I am a beginner in this. And my objective is presently just digital display (online). So I'm not looking at anything extreme. Right now I'm just looking to move beyond the kit lens. I was early on thinking of the 10-22mm Canon zoom lens. But once I thought about the geometry involved in a pano, I decided going extreme on a RL lens was not getting me as much (even though a 10-22mm zoom would not be a perfect RL, anyway). So my thought was a couple of non-zoom lenses, one for pano and one for macro (and a remote control for both).


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PostPosted: Fri Oct 10, 2008 5:43 pm 
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hankkarl wrote:
Not sure what you mean why you never found any serious attempt to ponder ... lens types for spherical panos. Do you mean you like FE lenses because the center is better than on Rectilinear lenses, and is more important?

I neither like nor dislike fisheyes. Spherical panos have no center. My first opinion was that fisheye could be better because, as they use an "equisolid" projection (or about), they insure an equal repartition of image pixels in every direction. Then I realized that next to the circumference of the image circle they make a very unusual use of said pixels ! (when distorting shapes along this circle.)

The difference in cost between a fisheye (they are now quite inexpensive) and a very wide-angle lenses (most are very expensive, 10-20mm Sigma excepted) made my buying decision rather easy but besides that I still don't know which solution would be better if cost is equivalent or is disregarded.

Another side of the same question: is the Tokina fisheye at 17 mm preferable, equivalent or better than a 17-xx mm rectilinear zoom?

hankkarl wrote:
Sharpening gives you a chance to correct mistakes, etc. The lens is critical--you can add accutance (ie a sort of contrast) but not resolution (the sharpness of features as opposed to the contrast of the feature and background)

You cannot remove blur, you can only fool the eye into thinking it is less than it really is. So sharpening and other post processing are things we all try, try and try again (for the cost of our time) while lens resolution and contrast are something we cannot improve except by buying a new lens (or calibrating the lens)

I never use in-camera sharpening because I find subsequent sharpening impossible (sharpening artifacts being sharpened !) but believe some sharpening being needed (to compensate for anti-aliasing filter, demosaicing process and because we are used to film "chemical sharpening".) When printing, sharpening is best done when image print size is known. When using a viewer the image viewing size is not known because zooming is allowed (the viewer program should adjust sharpening dynamically, I set zoom limits and try to adjust sharpening accordingly.)

Besides that, no doubt the .mov (or equivalent) JPEG quality setting is the most important point for spherical panos resolution (no compression nor sharpening available for .swf files?)

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PostPosted: Mon Oct 13, 2008 8:44 am 
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GURL wrote:
I neither like nor dislike fisheyes. Spherical panos have no center. My first opinion was that fisheye could be better because, as they use an "equisolid" projection (or about), they insure an equal repartition of image pixels in every direction. Then I realized that next to the circumference of the image circle they make a very unusual use of said pixels ! (when distorting shapes along this circle.)

Ideally (or at least as I would expect) a fisheye lens would have subject focus field that is the (inside) surface of a sphere equidistant from the lens node, and would translate any angle of arc on that sphere surface into a equal linear distance on the flat image plane (film or sensor), regardless of how far from the center of the picture that angle is located. But maybe it is the case that (some) fisheye lenses fail to achieve that, and instead, translate that angle of arc to a longer linear distance near the edge. Maybe fisheye lenses are less expensive because this kind of geometric distortion tends to be tolerated more than in a rectilinear lens. People expect distortion in a fisheye lens, and if that distortion is not an exact angle to linear translation, most people would never know, or even care.

GURL wrote:
Another side of the same question: is the Tokina fisheye at 17 mm preferable, equivalent or better than a 17-xx mm rectilinear zoom?

I'm starting to question what a given focal length even means for a fisheye lens. For a rectilinear lens, it should behave geometrically like a pin-hole lens at a distance from the image plane equal to the focal length in consideration. But a fisheye has no such comparison. The only real comparison is if the image is projected onto the inside of a sphere that has its center at the pin hole itself. Then we have to translate that sphere onto a flat surface (unless we are studying the eye ball).

We can have a large image sphere, or a small image sphere, behind a pin-hole lens, and it would still give the same coverage. So the distance of this sphere from the pin hole doesn't really mean anything for determining how wide a fisheye lens actually is. I think the information we need to have for some fisheye lens is how many degrees of arc corresponds to each mm at the image plane, and if this varies across the images, how does it vary. That, and the coverage (how far until the lens vignettes unacceptably), should tell us what we can see in the lens (angle of view).

Hopefully, in the middle of the angle of view, the quality of an inexpensive fisheye lens is good. Then shoot more rows to get a wider pano using the good part of the lens.


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