Forum : Advice & Critiques

Can’t seem to get something to synth right? Curious about what lens is best? Ask your fellow Photosynthers here.


Topic: help! what lens to bring, house shoot

Report Abuse Report Abuse
atrchi (Over 1 year ago)
I have a Nikon D7000 (APS-C frame) with lenses: 11-18mm f/4.5-5.6, 18-105mm f/3.5-5.6 IS, 24mm f/2.8, and 35mm f/1.8. I also have an SB-800 flash.

I have a one-time opportunity (unpaid) to shoot an interesting home interior and want to make a photosynth out of it. I will practice in my own home first but I only have a few hours of free time. So...

Which lens should I focus my efforts on? I want to learn the other details of getting a good synth and not spend too much time trying different lenses.

Thanks!!
Hi atrchi --

The biggest choice you must face is whether to make a pano or a synth. Even though a synth has the capability to connect two rooms together, think about who will be viewing it. If you want really simple viewing, then a series of panos is probably the best thing.(For an example of a really complex house synth, which some people love but others find *too much*, see the one I shot a few years ago: http://photosynth.net/view.aspx?cid=0473fc18-8c4d-405f-854c-ce245c678816 )

If you make panos, I would use the wide end of your 11-18mm, ideally with a pano tripod head (such as Nodal Ninja).

If you make synths, then you'll want lots of focal length flexibility, so I'd use the 18-105.
atrchi (Over 1 year ago)
I love the house synth. Does the software automatically figure out the room-to-room connections or do you have to manually join them? I don't want to bite more than I can chew...

I don't have a pano tripod head... Can I shoot hand-held and still get good results for pano? Or is synth the way to go when you don't have a tripod?

BTW one other factor is that my 18-105 gets Lens Distortion Correction straight out of camera whereas the 11-18 does not (because it's a Tamron lens). Is this something I need to consider?

Thanks
Nathanael (Over 1 year ago)
Greetings, Atrchi, 

Yes, the Photosynth app for Windows http://photosynth.net/create.aspx automatically figures out how the images relate to each other - as long as you've shot photos that link the rooms. 

You should be forewarned that creating a masterful synth like David's does take a bit of trial and error. 

Tips on how to shoot photosynths can be found in: 
the official Photosynth Photography Guide, available from: http://photosynth.net/help.aspx#photosynthhelp
the official video crash course: http://bit.ly/howtosynth

unofficial tips from end users like me: http://bit.ly/sinkorsynth
Note: In that last link, I very strongly promote orbiting objects to help new users experience success, but that can lead to more photos than is enjoyable to view in the end and is extremely time consuming to shoot as well. It is a good technique from a modelling perspective, but you can see in David's synth that he does not use orbits and still comes away with a great synth.
Nathanael (Over 1 year ago)
As to your question about panoramas, you can get good results with a handheld camera, but even an ordinary tripod would help you with indoor panoramas. 

Basically, when you're shooting a panorama, you need to take the various input shots from as close as possible to the same exact point in the air. 

"Why is that?" the newcomer to panoramas will ask. 
The answer is that panorama stitching is 2D stitching. That means that panorama stitchers like Microsoft ICE http://bit.ly/microsoftice or Photosynth's mobile version of ICE for mobile phones http://bit.ly/photosynthforios expect all foreground objects to line up against background objects identically in every shot that sees those objects. 

When you move your camera's lens, foreground objects will line up differently with background objects and the panorama stitcher will have to either put multiple copies of something in the final panorama or leave something out, to avoid duplicates - neither case being desirable.
Nathanael (Over 1 year ago)
With panoramas, these stitching errors due to things lining up differently in the input photos will be more noticeable the closer things are to your camera's lens, because the differences in things lining up will be making up a much larger percentage of the photo. 

How this impacts you is that you'll be shooting inside a house (where almost everything will be relatively close to the camera). 

Here's a series of videos from different panorama app creators mentioning this need to keep your lens as stationary as possible. http://bit.ly/howtopano

A panoramic tripod head would rotate your camera around its lens or image sensor, but even a cheap normal tripod will probably help the camera stay in one place better than you trying to do so by hand. 

Again, doing some demo shooting in your own home will inform you better than I can tell you. 

Try taking some handheld shots, then download ICE and try stitching them to see if you're pleased with the results as a panorama.
atrchi (Over 1 year ago)
On my first synth attempt, the program ran out of disk space. I had to resize the photos to 1024x768 and then it was successful. Is this normal? Thanks
Nathanael (Over 1 year ago)
As to your lens distortion...

If you're shooting to make a photosynth, I don't believe this will impact you as Photosynth for Windows is resilient to changes in focal length. It doesn't handle shots from an ultrawide lens like a fisheye lens, but other than that I think you'll be okay.

If you're shooting a panorama, so long as you keep your focal length the same for all your input shots, I don't believe that ICE will care either. Again, ICE isn't compatible with ultrawide lenses like fisheye lenses, but within reason, I don't forsee problems. 

With panoramas, so long as you have some way to keep the camera stationary, you can get a much higher resolution panorama if you shoot zoomed in as far as possible.
Nathanael (Over 1 year ago)
Other basic panorama tips are that for the best blending you should shoot with the same aperture and shutter speed for all shots in a panorama if you want it to look like a single capture. 

Manually choosing a single focal length that will work for the majority of what will be in view in the panorama is another tip for perfect stitching. 

More panorama tips here: http://hdview.wordpress.com/2009/06/01/microsoft-ice-tutorials/
atrchi (Over 1 year ago)
Thanks for the tips... I'm going to stick with synths for now as it appears to be the more fool-proof of the two.
Nathanael (Over 1 year ago)
Hello again!

Were you creating a photosynth with Photosynth or a panorama with ICE when you say you ran out of disk space?

When you create a photosynth, you should have about twice the disk space free as the size of your photos.
This is to say, if you have 500 megabytes of photos for a single synth, then be sure that the hard drive on your computer where Windows' 'Temp' folder is has at least 1,000 megabytes of free space.

I suspect the error which you encountered was probably the "Photosynth ran out of memory" message, which is actually telling you that you ran out of RAM (which is different than hard drive space). 

32-bit computers can only use a maximum of 4 gigabytes of RAM and 32-bit programs (like Photosynth) can only use 2 gigabytes of that RAM. Not everyone who has a 32-bit computer has 4 gigabytes of RAM, though.

64-bit computers can use much more RAM. If you're running Photosynth on 64-bit Windows w/ 6-8GB, Photosynth can use up to 4 gigabytes of RAM.
atrchi (Over 1 year ago)
Yes I also thought the "out of disk space" was a bit weird. But that's what it said. And it makes no sense... I have 110GB free on C: and total 320MB of photos.

Now something funny... my synth is rotated in weird angles! The software doesn't know which way is down... I guess I have to ensure the camera is horizontal at all times?? http://photosynth.net/edit.aspx?cid=6313af99-665d-46b2-89c1-2af3a413d781
atrchi (Over 1 year ago)
that's a test on my living room... I'm just shooting everything at 11mm
atrchi (Over 1 year ago)
oh cool I found the "Photo Up" option under Advanced... problem fixed :)
Nathanael (Over 1 year ago)
You beat me to the punch with the 'photo up' option in the Photosynth editor. =) 
In the Direct3D viewer you can use the [Y] key to toggle between world up and photo up on the fly. http://photosynth.net/d3d/photosynth.aspx?cid=6313af99-665d-46b2-89c1-2af3a413d781

Although using 'photo up' results in the photos in your living room/kitchen synth being displayed right side up, the underlying reason that their contents weren't being shown level with 'world up' is because the point cloud has an incorrect twist in it. I believe that this is primarily due to the lack of a strong link between the kitchen shots and the living room shots. 

Other weaknesses are the dark corners in the living room which have motion blur in them due to the lack of light (fixable if you use your flash in darker areas) and when you're looking up at the ceiling light in the kitchen (white featureless ceiling and overexposed light with no details for Photosynth to latch onto).
Nathanael (Over 1 year ago)
Here are a couple of tiny examples to show you what 'World Up' ought to look like. 

Here's a mini synth that I made with five of David's photos. Pay special attention to the third photo. 
In Silverlight: http://photosynth.net/view.aspx?cid=0e3cae77-fe25-4bf7-a8db-d3af2f7c5da2
In Direct3D: http://photosynth.net/d3d/photosynth.aspx?cid=0e3cae77-fe25-4bf7-a8db-d3af2f7c5da2

Here's a YouTube video where they photographer intentionally took a crooked shot. http://www.youtube.com/watch?v=ze16G3_2Ras&t=5m35s
Notice how although the photo is displayed slanted, the contents of the photo are right side up.
atrchi (Over 1 year ago)
Thanks again. Lots of helpful tips here.
Nathanael (Over 1 year ago)
Your comment about EXIF data on your newer discussion jogged my memory about a tiny old thread on Get Satisfaction and when I found it and read it, I realized it was more closely to the end of this talk. Here it is. 
http://getsatisfaction.com/livelabs/topics/why_are_my_photos_sometimes_sideways_in_photosynth
You need to be Signed In to add a comment. (Are you new? Sign Up for a free account.)