How to Understand the Curves Tool in Photoshop

Two of the most important things I’ve learned to work with in the past couple of weeks are the Curves Tool in Photoshop (for post processing) and the Histogram tool (either in Photoshop or on your camera itself, for use either while taking pictures, or in post processing).

This article is about the curves tool, well worth the read.

-amrith

After you’ve mastered Levels , it’s time to take a step up to the tool that is probably the most useful for color and contrast control in Photoshop: Curves. As with levels, you should play around with the basic Curves command to get a feel for it.

Source: How to Understand the Curves Tool in Photoshop

Old memories … a foggy day on Memorial Day Weekend ’97

Was thinking about an old picture I took in 1997.

It is on flickr …

I had copies of this picture made and I used to have it hang on my office wall just as it is above. Look carefully, it is upside down … How often have you seen a duck swimmg in the air!

Full Corn Moon

Today was the “Full Corn Moon” and I was lucky enough to get a clear night.

Full Corn Moon, September 4, 2009
Full Corn Moon, September 4, 2009

You can see a larger image by clicking on the picture above.

The moon is barely visible in the first image, hidden by the trees. In the second and the third, it makes it out of the trees just as the sun is setting behind me.

When “free” isn’t quite “free”. Or, remember to read the fine print on online photo sharing sites.

A quick comparison of some online photo sharing sites.

I have been a happy user of Flickr (I use the “frugal” account) till yesterday when I got a big pop-up box about a 200 image limit. Apparently flickr does offer unlimited free image storage but the fine print says that only the most recent 200 can be shared. Not the worst thing in the world but I began to think of all the other things I did not like about Flickr and so I started to look around and see whether I had some other alternatives.

There are any number of online image sharing sites. Many of them are also linked with photo printing services, and arguably that is where the money is. It appears that the devil is most certainly hiding in the fine print. Here is a short summary of what I found. I’m planning to move to Shutterfly; do you have some experience with them which makes this a bad idea?

Free Account

Paid Accounts

Flickr

http://www.flickr.com/help/limits/

Free account has unlimited (modest resolution) image
storage. No more than 200 can be shared at a time. There are upload limits on the number and size of pictures that you can upload.

Unlimited upload, storage and high resolution storage.

$24.95 per year

Photobucket

http://photobucket.com/faq?catID=29&catSelected=f&topicID=320

http://photobucket.com/faq?catID=41&catSelected=f&topicID=323

http://photobucket.com/faq?catID=39&catSelected=f&topicID=520

Free account has limited (modest resolution) images.

Periodic logins are required; failure to do so will deactivate
media

Unlimited capacity, FTP uploads (what a concept), no
advertising, personal URL’s

$24.95 per year

Shutterfly

http://www.shutterfly.com

Free unlimited storage of pictures. Images stored at high resolution. But you cannot download at high resolution. Personalized web portal.

I don’t think they even offer a paid account option. My
kind of place!

Snapfish (HP)

References

http://getsatisfaction.com/snapfish/topics/downloading_snapfish_photos

http://www1.snapfish.com/helppricing#hires

Snapfish offers unlimited photo sharing and storage. Customers must be “active”. The bar for an active customer is that you just need to
make one purchase a year.

But read this
link
. You can store high resolution images but downloading high
resolution images is not free.

OUCH!

No paid account.

Picasa (Google)

1GB limit (seems odd for the company that claims that
storage is unlimited).

Other limits also apply.

No paid offering that I could find.

Smugmug

No ads! Now, isn’t this a great graphic to illustrate the  success in targeted advertising and reinforce their point?

Smug Mug No Ads!
Smug Mug "No Ads!"

Reference

http://www.smugmug.com/photos/photo-sharing-sites-compared/

No free offering. There is a 14 day free trial.

Standard: $39.95/year

Power: $59.95/year

Pro: $149.95/year

Winkflash

http://www.winkflash.com/

http://www.winkflash.com/content/storage.asp

Free image hosting.

Free unlimited storage.

Free high resolution image downloads.

100% FREE

Too good to be true?

MPIX

http://mpix.com/

Free site for 60 days. After that, need an order to keep
content online.

MPIX is a professional print outfit; online sharing is not
their primary business.

WHCC (White House Custom Color)

http://www.whcc.com/

WHCC is a professional print outfit. They don’t do photo
galleries and sharing stuff. Go here if you want serious prints.

Not offered.

Not offered.

I think I’m heading to shutterfly. On Sept 5th I found this Shutterfly article (answer id 181)

“Currently, we do not have full resolution downloading available. However, we do have an Archive DVD service that you can order which contains full resolution copies of your pictures. The images on an Archive DVD will not include any of the Shutterfly enhancements or rotations that have been applied to an image loaded to Shutterfly.”

What BS is this? I guess I’m going to stick with Flickr for a while longer.

Also read http://forums.dpreview.com/forums/read.asp?forum=1023&message=32634142

Are you getting the whole picture?

Human field of vision, the shortcomings of simple camera, and how to take breathtaking pictures with a simple point-and-shoot camera.

While taking pictures, the field of vision is something that is often overlooked. A normal point and click camera has a field of vision of about 40°x35°. But, the human eye(s) provide you with a field of vision that is almost 200°x130°. Very often, you come upon a sight that is breathtaking and you whip out your camera and shoot some pictures. When you get back home and look at the pictures on a PC monitor, they don’t look quite the same.

To get some idea of what a short focus length lens (wide field of vision) can do for you, take a look at this picture on Ken Rockwell’s web page. The image that I would like you to look at is  here. This awesome image is copyrighted by KenRockwell.com. If you are a photo buff, you should bookmark kenrockwell.com and subscribe to the RSS feed. I find it absolutely invaluable.

I don’t have this kind of amazing 13mm lens but a panoramic image using stitching can produce a similar field of view.

Panoramic image of a rainbow
Panoramic image of a rainbow

Panoramic images are a very cost effective way to get pictures with a very wide field of vision. If you are interested in all the science and technology behind the process of converting multiple segments of an image into a single panoramic image, you can refer to the FAQ at AutoStitch. There is an interesting paper on how all this works that you can read here and there is an informative presentation that goes with that paper.

Panoramic images are also better than short focal length lenses because there is less distortion towards the edges. Notice that the houses at the right and left edge of the first image above appear to be leaning. With panoramic stitching these effects can be eliminated.

Some quick tips if you plan to take a panoramic picture.

  1. Set the camera to manual exposure mode to reduce the corrections that need to be done in software.
  2. Use a tripod and make sure that you get a complete coverage of the area that you want to stitch.
  3. Make sure that you overlap images by about a third. I usually turn on the visible grid in the view finder to help with this.
  4. Take lots of pictures, there is nothing to beat practice.

In my previous post some panoramic sunsets were shown. I took several sets of pictures, such as the five below. These were then stitched together using a software called Autostitch. You can get a copy of autostitch at http://www.autostitch.net/

image-1 image-2 image-3 image-4 image-5

Enjoy!

Sunset in Rye, New Hampshire

I got two interesting pictures of the sunset in Rye, NH today. The two pictures were each made by tiling 5 images using autostitch.

The two pictures are five minutes apart and the colors changed quite interestingly in that 5 minute interval.

And about five minutes later

I have reduced the size on these images to 70% so that they show up ok on the blog page. Larger images are on flickr (use the left panel).

Highland Light, Provicetown, MA

If you have ever been to the Highland Light Lighthouse at Provincetown, you will likely recognize the picture below. The image is panoramic and the high resolution image is 15MB and about 13k pixels wide. The image appears cropped here, you can see the complete image at flickr (link on the left).

Highland Light, Provincetown, MA
Highland Light, Provincetown, MA

The image is a composite of 10 discrete images that were stitched using AutoStitch. The software is available for free evaluation at this site.

For more information about Highland Light you can visit their web page at http://www.lighthouse.cc/highland/

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