24mm TSE for flat stitch panoramas

[howard_slavitt2]

Is anyone using the 24mm TSE for flat stitch panoramas on a full frame

digital? I have the 45mm TSE and am loving it for panoramas -- very easy to

align and merge together for excellent panoramas in Photoshop. I plan on

getting the 24mm TSE for the same purpose (and other purposes), but can't

remember seeing reference on the web to people using the 24mm TSE for this

application. Why not, or am I just missing it? I know the 24mm TSE is

supposed to have varying quality, so presumably the edges and corners will be

softer when full shifted at 11mm. How much of the frame would one lose to soft

corners if stopped down to f11 - f16? Thanks for the help. Howard

[mark u]

This is well worth a read:

 

http://www.outbackphoto.com/workflow/wf_58/essay.html

[robin_sibson1]

My experience with my TS24 on film is that it may not be perfect, but it delivers the goods, and you should be able to get acceptable corner quality even at full shift if you stop down to at least f/8.

 

The article Mark U has pointed you towards shows you how to avoid parallax errors by moving the camera body by the amount you shift the lens, but in the opposite direction. This should produce a near-perfect stitch, and will give a "58mm by 24mm" image (36mm + 2 x 11mm of shift) if you do it with a FF camera.

 

What I have not seen is any comparison of this rather laborious technique with the simple alternative of using a wide lens and cropping. With a 24mm lens, the sides of a 58mm by 24mm frame are at the same angle to the axis as those of a 36mm by 24mm frame photographed with a 15mm lens. So you could get nearly the same coverage by photographing your scene with the 16~35 set at the wide end, and slightly more coverage by using the 14/2.8, in each case cropping the 24mm by 36mm frame to 15mm by 36mm. My guess is that this would not produce as high-quality a result as stitching, but it would be interesting to have some evidence.

[andy_jones2]

Robin, You are right, the stitch just increases the FoV captured by the lens so it looks like

(ideally identical to) the wider lens. The reason people take the trouble to do stitching is

simply the ability to get more pixels for the given FoV and make BIGGER PRINTS of the same

quality. For your horizontal shift, you get ~65% more pixels by stitching (compared to one

image of 24x36) and with the wider angle prime you need to throw away pixels from the top

and bottom for the same composition. Thus the stitching gives you about 2x as many pixels

compared to the single shot.

[robin_sibson1]

Andy, yes, I certainly understand that to be the reason for stitching. In fact the pixel gain is more than you suggest: moving from a 15mm by 36mm image to a 24mm by 58mm image gives 2.6 times as many pixels, that is, (58/36)^2. That's why I guess it probably gives a higher quality image, and my question really is how much difference it makes in practice.

[qtluong]

Since you are mentioning panoramas, I assume you intend to take the pictures in horizontal format and shift the lens horizontally. If so, be aware that the shift limit in that direction would be 8mm, rather than 11mm. Shifting more causes vignetting. Even shifted at 8mm, the corners at the limit of the image circle are noticeably softer. In general, in my architectural compositions, those corners are sky, but if they had more texture, this might be objectionable.

<a href = "http://www.terragalleria.com">Terra Galleria Photography</a>.