topic Re: Ultra-wide angle zoom question in EF & RF Lenses

Ultra-wide angle zoom question

billybobboy42 — Thu, 12 Sep 2013 21:12:02 GMT

Back in July I purchased a Canon 6d and the EF 17-40L lens. My first shooting attempt with this equipment was a sunrise panorama of a beach resort skyline near where I live. I used a tripod and took 6 frames with the suggested 60% image overlap, with the intention of creating a stitched panorama. My camera angle to the view was fairly close to perpendicular. At home I first tried stitching with Photoshop Elements. It managed to stitch, but poorly. One frame was excluded, which of course rendered the final product unacceptable. So, on to Canon's DPP stich program. Not one image was useable. I forgot the error message, but it kept telling me to delete certain frames, which led to deleting the entire shoot. So, I guess this is a "lens 101" question(s). Is this lens suitable for landscape photography? Is there a technique to using wide angle lenses in landscape photography? The focal length I used has long since left my brain, but let's assume it was set at F28, or about in the middle of the range. I also have a Canon EF 70-200L series. Perhaps I should have used it. But sunrise waits for no one.

Any helpful comments will be greatly appreciated.

Bill

Re: Ultra-wide angle zoom question

Skirball — Thu, 12 Sep 2013 21:35:06 GMT

I don’t know that I’d blame the lens, I’d look to the software first. I’m not much of a fan of Elements, and didn’t use it much even though a free version came on my computer. I’d try a dedicated stitching program if you’re into stitching, otherwise, try it in Elements again. Sometimes I get bad stitches in Photoshop, I just do it again and it usually works.

As to the focal length: personally, if I’m going to be stitching then I’d use a longer focal length unless I specifically was going for a distorted/exaggerated look that you get with UWA. If you’re just trying to get a lot in your image, use the sharpest lens you have and stitch it together. Do you have a 50 prime or something?

Re: Ultra-wide angle zoom question

hsbn — Thu, 12 Sep 2013 22:17:02 GMT

UWA lens is great for landscapes. It's great for panorama too especially 360* pano. If you run into problem stiching them together, maybe there is something wrong in the capture. Is there a lot of distortion in the photo (it should not be since you said you put the camera level)? Is there a way you can post a few photos? It wil be clearer to troubleshoot with some photo. Here is the pano with 6D + 17-40 @ 17mm I took earlier this year.

Re: Ultra-wide angle zoom question

cicopo — Thu, 12 Sep 2013 23:00:08 GMT

I've only tried a pano once & it worked fairly well but wasn't anything great. You mention sunrise which leads me to ask whether the lighting was drastically different across the set of photos. If it was that might be why the software doesn't like certain frames.

Re: Ultra-wide angle zoom question

billybobboy42 — Fri, 13 Sep 2013 13:52:35 GMT

Cicopo, I believe the lighting was pretty consistent across the exposures since I took the shots quickly. As soon as I get a chance, I will post some photos as requested by Hsbn.

Re: Ultra-wide angle zoom question

ebiggs1 — Fri, 13 Sep 2013 14:57:15 GMT

I don't know what went wrong with your pana but I did one this summer that was about as bad of conditions as you could want. I use Photoshop CS6 for my stitches. I will say with out reservation, the 17-40mm f4 is not the cause of the failure.

I offered our local community theater my services to do their pubs and promos for the show they were doing. It was Joseph and the Amazing Technicolor Dreamcoat.

I was told thanks but no thanks as they already hired a photographer. Even though I offered it pro bono.

I also play in the pit and I always have a camera with me. This occasion I hand my 7D with a 50mm f1.4 lens on it. I snapped a few quick shots of some of the actors and I had a few pretty random shots of the closing bows.

Well it seems Mr. Hired Photographer failed to get a shot of the entire cast. They came to me and asked if I did. Long story short, I found four shots that did get the entire stage but they were no where what you would do if you wanted a great pana.

I stitched them in PS and here is how it turned out. So what went wrong with yours? Who knows but keep at it. Your photos need to have common points in each photo. Although I didn't do it for this pana because I wasn't going to even make one, but turn your camera vertical when you shoot panaramas.

Re: Ultra-wide angle zoom question

Skirball — Fri, 13 Sep 2013 15:17:53 GMT

@billybobboy42 wrote:
Cicopo, I believe the lighting was pretty consistent across the exposures since I took the shots quickly. As soon as I get a chance, I will post some photos as requested by Hsbn.

That doesn't matter, if you don't lock your exposure the camera will still assess each shot individually, and if there happens to be more dark subject in the center on one shot (e.g. mountains on the horizon), then more sky on the next, you're going to get different exposures. Lock your exposure if you know you're going to do Panos, it'll help ease the stitching.

Re: Ultra-wide angle zoom question

billybobboy42 — Fri, 13 Sep 2013 18:14:13 GMT

Here are the 5 frames I took to be stitched. What I forgot to mention earlier was that I was using the 6D's HDR function as well. I set it for -3, 0, +3 exposures. Hence the .jpg format vs raw (the HDR function only works in the 6D with .jpg files). I want to mention right up front that I don't suspect lens problem. It's likely the "photographer" that is in error. And if so, I just need some advice as to how to do better. I've done successful panorama stitching with my old 20D, but of course using an EF-S 17-85 lens.

I also tried stitching again, using Canon's photo stitch software, so that I could get the "problem" message; and here it is: "can't merge because images with very short focal length are included". What would "very short focal length include"? 17, 25, 30?

My intention was, provided the stitching worked, to enlarge the merged photo 3 clicks in Photo Shop Elements and then crop off a bit of the top sky area. A test enlargement of one of the frames turned out decent enough to actually view the buildings.

Re: Ultra-wide angle zoom question

ebiggs1 — Fri, 13 Sep 2013 19:06:42 GMT

In order for a stitch to work your photos must have common points that the software can select to merge the like areas. Although yours look blue and have "similar" points, none of them are alike enough. Somehow you changed the size of most of the areas where PS would grab for comparison.

This is probably the best it can be in this instance. I could not get any points to line up.

Re: Ultra-wide angle zoom question

ebiggs1 — Fri, 13 Sep 2013 19:07:46 GMT

Did you move or walk a bit between each shot?

Re: Ultra-wide angle zoom question

hsbn — Fri, 13 Sep 2013 19:28:34 GMT

I got a little different result with Ebiggs using Auto Giga Pano software. But it could be due to the files are small.

Re: Ultra-wide angle zoom question

billybobboy42 — Fri, 13 Sep 2013 19:35:23 GMT

No, the camera was on a tripod. The only part of the ball head that was loosened was the horizontal function, which was tightened before each shot. As I mentioned earlier, PhotoShop Elements managed to stitch 4 of the 5, but the missing one was in the middle, making the image worthless.

Re: Ultra-wide angle zoom question

billybobboy42 — Fri, 13 Sep 2013 19:44:44 GMT

The file sizes ranged from 3.49 mb to 3.61mb. Your result appears to have produced the correct breadth of the panorama. However, it looks to me like part of the clouds are a bit low. Also, I'm not sure that the files as posted are the same resolution as my originals.

Re: Ultra-wide angle zoom question

Skirball — Fri, 13 Sep 2013 20:00:35 GMT

If you want HDR you should do each "frame" in HDR first, then stitch. But for something that simple I'd just "stitch" it by hand.

Open in Elements

Expand the canvas size (little on top and bottom, a lot on the sides)

Import the other shots

Move them around until they look good

Mask each layer and use a soft brush with low fill to blend the layers into each other

I would also create a curves adjustment layer for each layer, turn it into a clipping mask (Ctrl alt g) so it only affects the layer below, and you can fine tune your exposure to make sure they match.

Re: Ultra-wide angle zoom question

ebiggs1 — Fri, 13 Sep 2013 21:09:18 GMT

Something changed because the post of the dock(?) is not the same size in each frame. Neither is the clouds in the back ground. Unless you didn't size them evenly when you uploaded them?

Re: Ultra-wide angle zoom question

billybobboy42 — Sat, 14 Sep 2013 17:10:23 GMT

I need to respond to a couple of issues brought up:

1)HDR - the hdr function was completed at each shot. In this function the shutter triggers 3 times; one at each of 3 exposure settings, then the camera processes the three into one frame. While the camera is processing the image(s) the camera is not available for another exposure. For all shots, I used a Canon cordless remote control .

2) Size of dock pier post - the exposures I posted are the original frames; thus no post camera processing on them. The post was only a foot or two from the camera which might explain the size error or distortion. But I have no clue re clouds.

As I mentioned earlier, I do not remember what focal length I used; however, it may very well have been at 17mm. Notice how distant the scene is of the resort skyline. I do remember that the scene as viewed thru the live screen appeared a bit distorted or stretched.

For the record, I took several sunrise shots (at the ocean front from a balcony) with this lens on successive days previous to this panorama attempt. They were not taken to stitch, but just individual shots. They turned out quit satisfactory. I even got the moon and sun within the frame, but of course the moon looked way to far away. In any case, no distortion.

Hope this clears up some of the questions.