Panorama

<p>Hello all,<br /> <br /> I am just getting into panoramic photography and have a few general questions. There didn’t seem to be a panoramic specific discussion group so here I am. First of all I use a Nikon D80 with a variety of lenses from 18mm-50mm when I try and shoot panos. I have read that it is better to shoot in portrait rather than landscape and of course using manual mode. My question really is about the number of shots, and how that does or does not relate to the aspect ratio of the final photo. For instance, I shot a 360 view off my roof with a 50mm and overlapped each photo by about 33%. To get all the way around, it took about 40 individual pics. The resulting stitched photo’s aspect ratio was far to great to really ever consider printing. Was this a product of too many photos, or perhaps not using a wide enough lens? <br /></p>

<p>Hi - the answer is simply when considering the end product you have to think of the sum of the parts...ie if you are overlapping 33%, then the total length will be approx. 1-0.33 x 50 x length. Since you are shooting only 1 horizontal layer then of course it will be only 1 unit high. If you want to create a specific aspect, you need to really plan in advance if you will be stitching just horizontal rows, vertical columns or both. As you suggested, you might reduce one component by using a wider angle lens. You can create a very large pano (horiz & vert) and then crop to a desired view. Most people I know don't generally create panos beyond around 180 degrees because of the very problem you mentioned, if one is going to print the end result. OTOH, if one is using more sophisticated computer software to view online results...such as virtual tours in spherical projections. Google Andrew Neming's site for some very interesting experiments in pano work. Good luck and enjoy!</p>

<p> </p>

I'm not too sure why you ended up with about 40 photos. A 50mm lens has a horizontal field of view of about 40 degrees. With the 1.5 cropping factor of the D80 that would be actually about 26 degrees.

 

360/26 = (apprx.) 14 photos. Allowing for 30% loss each that gets you about 20 photos to cover the 360 degree panorama.

 

Stitched together at a 4 inch high print height, you would need a print of 4 inches by 120 inches or 4 inches by 10 feet.

 

The wider the lens you use the greater the loss in perspective. The 18mm lens would reduce the number of photos needed and the print to about 4 inches by 3.5 feet but everything would look about three times further away and about three times smaller. A tree that looks about one inch high on the 10 foot long panorama would look about 1/3rd inch high on the 3.5 foot panorama. If it looks 100 feet away on the 10 foot long panorama, it will look 300 feet away on the 3.5 foot panorama.

<p>As Stephen intimated, you can stack courses of images (think like blocks in a cinder block wall).<br>

Also, hold the camera in the portrait mode to 'make' taller shots. In the example below, that gives you an aspect ratio of 96mm x 240mm (35mm film format for argument's sake), i.e. 1: 2.5. It's a lot of work, and post production but gives you a more 'rectangular' pano.</p>

<p>Jim M.</p><div></div>

<p>Hi Jonathan,<br>

The aspect ratio you get in the end depends on the horizontal and vertical fields of view. If your horizontal field of view is 360 degrees, you'll need a very wide angle lens in portrait mode or multiple rows to create a decently printable aspect ratio. It also depends a lot on the type of projection you use. You can create a 'fisheye' like stitch that is not as wide but has a lot of distortion.</p>

<p >To do panoramas-</p>

<p >for panoramas- -use tripod. you must keep it level with the horizon. if your tripod does not have a level builtin then buy one that slides into your flash hotshoe. again make a max effort to get the camera level.</p>

<p >-for exposure. set the exposure by pressing halfway and noting the fstop and shutter speed. you are trying to find the brightest part of you panorama scene to be. once you have found the brightest check the fstop and shutter speed. put camera into manual metering mode and use those settings. do not change them for any part of the panorama.</p>

<p >-lens selection. i shoot mine with a 20mm. note: SHOOT THE LENS VERTICALLY. this is the only way to get some vertical scene, otherwise the panorama will be shaped like a hotdog. Note- if the panorama is a vertical panorama then you shoot landscape. this is why i went to a 20mm. in vertical you are cutting your angle of view way down. my tripod has degrees engraved in the mount, i was shooting at only a 15 degree spread and in looking at the shots before stitching there wasn't that much overlap. i later shot panoramas with 35mm 50mm 70mm; the hot dog effect was more pronounced. the panorama itself did work. With higher mm lens you would have to go to double rows.</p>

<p >-determine in advance the center point of the scene and try to go X number of shots on each side of it. for me with my setup a 120 degree scene is 7 shots; the center and 3 on each side. if i go with a 35mm lens then a 120degree scene will take 13 shots. no matter what lens you use realize that you are adding only 33% new scene with every shot, the rest is overlap for the right and left adjoining shots. the only exceptions are the end shots in the whole scene. it is possible to add another row above and/or below the first one. this would help the vertical look especially if you are using a 50mm or longer. for multiple rows are the same as 1 row, but you know have to overlap on the vertical as well as the horizontal. you must make sure that there are no gaps.</p>

<p >- i stick my hand in front of the lens and shoot, then shoot the panorama, the 7 shots, then put hand in front of lens and shoot. later i know that everything between hands is the panorama.</p>

<p >-i have used cs2 or the panorama factory software to make the panorama. for either couldn't be simpler simply select the shots and it does the work. this is where using a level pays off. the software is leveling the scene to make the long rectangle, but if the scene was not as level as possible in the first place the vertical becomes less and less(you end up with hotdog shape). so having the tripod and camera level is very important. also when mount and shooting vertically make sure the camera really is vertical, carefully check by looking threw the viewfinder. some tripod vertical adjustments actually go past true vertical, mine does even though it says 90 degrees.</p>

<p >-be sure to use a cable release or the selftimer.</p>

<p >-on focusing- what i do is to simply preset the 20mm lems at infinity, because of depth of field everything from 5.64ft to infinity is in focus at f11.0 distance 200ft. you can also use a hyperfocal focus setup. but thanks to the DOF table, just setting the lens at infinity is simpler. -i left WB alone, that is set at AWB; or you can use a preset setting like sunny or cloudy, but once set do not change it till panorama shots are done.</p>

<p >-online depth of field calculator available here- <a title="Click to open link in a new browser window" href="http://www.dofmaster.com/dofjs.html" target="_blank">http://www.dofmaster.com/dofjs.html</a> </p>

<p >-parallax error. It is usually not so much a problem outdoor shooting. This is because the distances are greater than inside. In any event if you shoot panoramas outside and at short distances OR any inside any building, you should be thinking of getting a panorama tripod head. This is to eliminate parallax error. I have the panosaurus pano head, cheap durable, and it works.</p>

<p >-for panoramas, the software i use is either panorama factory orPTGui or cs2. the one that works best for me is PTGui. i have since gotton PTGuiPRO, expensive but worth it. has many features and abilities that the other software does not have, including the ability to process 360 and 720degree spherical panoramas, plus many projection types and it does raw and hdr panos.</p>

<p >-on post shooting work. If jpeg DO NOT PP. just use as is. After the pano is made then pp as desired. If raw, does your panorama software do raws? Not all do. If yes raw batch convert only. Do not adjust any 1 shot. All shots must be the same before the pano is made, then do any pp you wish but on the whole pano.</p>

<p >If any pp work is done to the pano before stitching then there will be a difference in the sections, and you could(probably?) get vertical bands where the sections join. </p>

<p >Any questions, please ask. gary</p>

<p >--------------------</p>

<p >QTVR=QuickTime Virtual Reality</p>

<p >i have made some QTVR for my own use and showing to my relatives and friends. On my pc. Use google for QTVR and you will get websites that have MANY MANY QTVRS to see. They can be seen using Quicktime 7.x or later. </p>

<p > </p>

<p >it is really not a problem if you happen to have the right gear. i use a 6mp dslr, the panasaurus panorama head, a tripod, cable release, and a sigma 12-24mm zoom at the 12mm setting. (i already have my lenses calibrated to be used on the nodal point. i know the numbers, just dial them in). for the QTVR i make 2 complete circles, of 12 shots each, each with the pano head tilted up 30degrees and tilted down 30degrees. except for a very small black circle at the top and bottom, it is is a 720degree spherical panorama. in the future i am thinking of getting the 8mm sigma or the 10-17pentax lens. this would eliminate the black circles. once setup the shooting takes maybe 10-15minutes.</p>

<p >prior to running in the software, i batch process the images, jpegs, in pe6. i use auto level, auto contrast and auto sharpening. once in PTGuiPro they are rotated right side up as a group.</p>

<p >it is then run in PTGuiPro7.8 software to make the finished result. the software runs about an hour or a little less to make the circular image, the QTVR. It is saved as a special format in a folder, and can be viewed in Quicktime 7.x or later. The quicktime 7.x or later can turn the image in a circle or move it vertically.</p>

<p > </p>

<p >note hdr QTVR are possible but then you would be shooting multiple exposures of each frame. PTGuiPro will make them. there may be other software that does, but PTGuiPro is the only one that i know that does.</p>

<p > </p>

<p > </p>

I have only made one panorama shot in my entire life. The occasion was my 40th class reunion at Mass. Maritime Academy. I took about five shots, hand held using the 35mm focal length of a Canon A570 trying to keep the horizon at the some position in the viewfinder. Then I had to do a lot of cropping and stitching to get this result:

 

http://www.geocities.com/dainisjg/MMA4pan.jpg

 

Not the best that could be done but good enough to e-mail to grads who couldn't attend to show what the campus now looks like. I believe the coverage was around 90 degrees.

 

Printed out on a 4 inch wide roll of photo paper, that would be about 4 x 18 inches.

 

Note: in doing the quick calculations in my head for my first post above, I made an error. I correct it here:

 

 

Stitched together at a 4 inch high print height, you would need a print of 4 inches by 84 inches or 4 inches by 7 feet.

 

The wider the lens you use the greater the loss in perspective. The 18mm lens would reduce the number of photos needed and the print to about 4 inches by 2.3 feet but everything would look about three times further away and about three times smaller. A tree that looks about one inch high on the 7 foot long panorama would look about 1/3rd inch high on the 2.3 foot panorama. If it looks 100 feet away on the 7 foot long panorama, it will look 300 feet away on the 2.3 foot panorama.

 

The big problem is trying to do a 360 degree panorama and get a manageable size with correct perspective.

<p>Hi, Jonathan. I've done a few panoramic photos, and only because of PTGUI did they turn out fine. It's an incredibly good program!</p>

<p>I also read that we should orient the camera in portrait mode (when the pano will be horizontal). I do that, and here's my reasoning: the resulting pano (when all frames are "stitched" together) will give you irregular borders. Some of this is going to get cut off when you crop while post processing. I would much rather cut off the edges of the original individual frames that have the most distortion and possible vignetting. I always try for the best quality results possible. </p>

<p>I also level my camera. I feel the final result gives you a more natural looking pano. Also, less of the individual photos are "wasted" because they match up perfectly.</p>

<p>A couple of things to remember: 1) determine your settings and shoot in manual mode (you already know that) 2) never use a polarizing filter </p>

<p>I try to take enough photos to cover what my eyes normally see in a scene. I know there are times when 360 degrees is fun, but as you have found out, in order to print the photo the height is so small that you don't see enough detail. It's not that you did anything wrong. Just consider the ratio of 360 degrees to the height of what you wanted to cover...your result was inevitable, unless you also photographed a second or third row above and/or below the original row of photos. I will normally print panos on 13 X 38 paper, and I try to fill most of the paper.</p>

<p>I usually overlap about 33% as well, but I don't get too detailed with this. I estimate the overlap. I normally bracket each frame, just to be safe. Accurately rotating the camera on the nodal point is most important when there are objects in the foreground.</p>