Sigma 10-20 Corrections?

I just ordered a 10-20 4-5.6 from a fellow POTN member, and I am quite excited to get it. I was wondering how hard it is to make verticals look vertical, etc.? I will be using it for interiors and architectural photography and really want those verticals to be correct. Does CS5's lens correction work well here or are there other tips and tricks I need to research?

Thanks!

For interiors and other situations where you want correct parallel lines, you bought the wrong tool.

imsellingmyfoot wrote in post #15714740
For interiors and other situations where you want correct parallel lines, you bought the wrong tool.

Of course I did buy the wrong tool. I cannot afford a TS lens right now. This will get me closer than my 18-55 kit lens, which is my current widest option. Do you have some examples of your work done with the correct tool? You know, for inspiration?

Thanks for offering feedback, however, I am really looking for advice on the best ways to correct as much distortion as I can, regardless of one's opinion on the utility and serviceability of the tool in question. Thanks.

I used the 10 to 20 and some perspective correction in Photoshop the other day. I got it reasonably close to how I thought it should be but I ended up having to crop out a lot of the picture. So it can be done but you lose a significant portion of the picture.

There are two kinds of issues - 1) Lens distortion and 2) perspective corrections. Lens distortion is inherent in the optics, perspective distortion comes form how you position and orient your optics in the scene.

As @imsellingmyleftfoot does not elaborate on his/her mysterious comment, it is not really possible to tell what they are getting at. Presumably they wanted you to have purchased a tilt-shift lens so that you can maintain parallel verticals by making movements within the optics to preserve these structures. If so, I can imagine it would have been helpful to have mentioned that.

EDIT - I posted after you folks already had the conversation above. Mystery solved.

Because you do not have a tilt-shift lens, you will need to correct your images in post to preserve parallel verticals. There are a number of ways to perform these corrections but not necessarily inherent in CS5. To correct the lens/optics distortion you will need something that has a "lens profile" or similar. This kind of correction may be available for your camera body+lens in ACR/LR, otherwise, the king of all optical corrections of this sort is DXO Optics Pro. Either way, this will correct for the optics. The Lens Correction tool in PSCS5 - again assuming you have a lens profile available for your camera+lens combination - would be similar to the ACR-LR correction.

The Lens Correction tool aslo has perspective correction (horizontal and vertical). Some tools, like DXO Viewpoint, have a "force parallel" or similar perspective correction that permits you to select the 4 corners of a keystoning object that should be parallel and the vertical and horizontal perspective correction is applied automatically. You can also use a panoramic stitching tool like Hugin (free) and tell it to correct vertical lines that should be vertical. It will perform a warp of the image to force those lines to be vertical.

The downside of all of this correction in post is that you will lose image pixels to the correction. Plan for this when shooting. Note that in PSCS6, there is an additional tool called the "Adaptive Wide Angle" tool that you should look into to see if using that approach is worthy of an upgrade. I can imagine that you can google the term and a few videos will pop up.

I have not used the lens you have, so I do not have a specific recommendation for the approach.

If you need a little inspiration, here is the portfolio of michael james, a real estate and architectural photographer who is active in the HDR community and does not, to my knowledge, use a tilt-shift lens.

http://digitalcoastima​ge.com/portfolio/index​.html

here is his blog:

http://hdriblog.com

and here is a webinar:

Part 1

http://www.youtube.com​/watch?v=mdRogMSf4Tk

and Part 2

http://www.youtube.com​/watch?v=bKVIsztmmcQ

kirk

kirkt wrote in post #15714822
There are two kinds of issues - 1) Lens distortion and 2) perspective corrections. Lens distortion is inherent in the optics, perspective distortion comes form how you position and orient your optics in the scene.

As @imsellingmyleftfoot does not elaborate on his/her mysterious comment, it is not really possible to tell what they are getting at. Presumably they wanted you to have purchased a tilt-shift lens so that you can maintain parallel verticals by making movements within the optics to preserve these structures. If so, I can imagine it would have been helpful to have mentioned that.

EDIT - I posted after you folks already had the conversation above. Mystery solved.

Because you do not have a tilt-shift lens, you will need to correct your images in post to preserve parallel verticals. There are a number of ways to perform these corrections but not necessarily inherent in CS5. To correct the lens/optics distortion you will need something that has a "lens profile" or similar. This kind of correction may be available for your camera body+lens in ACR/LR, otherwise, the king of all optical corrections of this sort is DXO Optics Pro. Either way, this will correct for the optics. The Lens Correction tool in PSCS5 - again assuming you have a lens profile available for your camera+lens combination - would be similar to the ACR-LR correction.

The Lens Correction tool aslo has perspective correction (horizontal and vertical). Some tools, like DXO Viewpoint, have a "force parallel" or similar perspective correction that permits you to select the 4 corners of a keystoning object that should be parallel and the vertical and horizontal perspective correction is applied automatically. You can also use a panoramic stitching tool like Hugin (free) and tell it to correct vertical lines that should be vertical. It will perform a warp of the image to force those lines to be vertical.

The downside of all of this correction in post is that you will lose image pixels to the correction. Plan for this when shooting. Note that in PSCS6, there is an additional tool called the "Adaptive Wide Angle" tool that you should look into to see if using that approach is worthy of an upgrade. I can imagine that you can google the term and a few videos will pop up.

I have not used the lens you have, so I do not have a specific recommendation for the approach.

If you need a little inspiration, here is the portfolio of michael james, a real estate and architectural photographer who is active in the HDR community and does not, to my knowledge, use a tilt-shift lens.

http://digitalcoastima​ge.com/portfolio/index​.html

here is his blog:

http://hdriblog.com

and here is a webinar:

Part 1

http://www.youtube.com​/watch?v=mdRogMSf4Tk

and Part 2

http://www.youtube.com​/watch?v=bKVIsztmmcQ

kirk

Awesome. Thank you! That points me in the right direction.

kirkt wrote in post #15714822
the king of all optical corrections of this sort is DXO Optics Pro.

And, thakfully, it is no longer necessary to use the whole, clunking, slow Optics Pro application just for the excellent optical corrections. Not now that they're released DxO Viewpoint - available as a stand-alone app and a PS and LR plugin.

True, but Viewpoint does not perform optical (lens+camera) based corrections, only perspective corrections and anamorphosis. That is, Viewpoint does not have lens+camera profile-based corrections.

kirk