Photo Topic articles are designed to help artists use their digital cameras more effectively, and know when and how to use different digital formats & image sizes for their images. 

--- This page contains the Photo Topic Index and the latest two Photo Topic articles.   All previous PT articles are available on request:   Send Mark an email and specify which Topic(s) you would like to receive, and they will be emailed to you.  Please share these notes freely.   

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Photo Topics Index

1. Digital File Formats and File Sizes: Tiffs, Jpgs, File Compression, Preserving Image quality, Emailing and Web Site use. (Jan 2011)

2. Digital Image Size and Image Quality: Megapixels to Megabytes, Image Size vs Document Size, Image Resolution. (Feb 2011)

3. Digital Image Quality and Resolution: Components of Image Quality, Hi–Res Images, ZAPPlication and CaFE Image Formats. (May 2011)

4. Resizing Digital Images: 16 and 8 Bits, Color Space, Steps in Resizing the Image, Creating ZAPP and CaFE formats. (May 2011)

5. Digital Camera Controls – Part I: Focus, ISO, Shutter Speed, Aperture, Focal Length, Color Balance, Image Quality. (Aug 2011)

6. Digital Camera Controls – Part II: Automatic Modes, and Which Mode to Use for Different Photographic Situations. Auto vs Manual, Basic Automatic Modes, AUTO, Portrait Mode, Landscape Mode, Sports Mode, Close-Up or Macro Mode, Advanced Automatic Modes, Program Mode, Shifting the Program. (Oct 2011)

7. Digital Camera Controls – Part III: Advanced Automatic Modes. Review of Program Mode, Using Shutter Priority Mode, Using Aperture Priority Mode. Setting ISO, Setting Aperture, Setting Shutter Speed, plus Additional Controls. ISO Tips, Shutter Speed Tips, Tripods & Bracing the Camera, plus Birthday Party Q & A. (May 2012)

8. Easy Summer Photos I: Quick shots for Email, Craigslist and Ebay. Keep It Simple, Lighting, Taking the Shots, Flash Tip, 10 Minutes, Quick Approach. (Jun 2012)

9. Light I: Outdoor Light, Part 1 – Winter Light, Summer Light. The Role of Outdoor light in our photography, and how it changes from season to season, and throughout the day. (Jan 2013)

10. Light I: Outdoor Light, Part 2 – Atmosphere & Weather. How the character of our images is influenced by local Atmospheric and Weather conditions. (Mar 2013)

11. Easy Summer Photos II – Using Outdoor Light Indoors. Using the Sun as the Light Source Indoors, and how to select and modify its characteristics. (May 2013)

12. Emailing Digital Images. How to size images for quick and efficient emailing. Plus how to preserve original image size of photographs when emailing high resolution images. (Jun 2013)

13. Setting Digital Camera Preferences – Contrast, Saturation, Sharpness – Part 1. How to select and set Contrast and Saturation levels for Jpg images. (Oct 2013)

14.  How Big is Big Enough?  Part I  – Image Sizes for Ebay. How to create excellent ebay images that are big enough!  (May 2014)

15.  Sizing Images for the Web  –  Part I.  How to size images of your artwork for posting on the web.  (Mar 2015)


                                                                                                                           Orvis Bamboo Fly Rod, c. 1978, ebay photograph

                                                                                                                           Orvis Bamboo Fly Rod, c. 1978, ebay photograph

Photo Topic 14, May 2014 – How Big is Big Enough? – Part I:  Image Sizes for Ebay

This summer I am again photographing vintage fishing rods & reels for posting on ebay and other websites.

Shooting Jpgs

When I shoot artwork professionally, I use a 15 MP Canon SLR and shoot RAW format (+ Large Jpgs for backup). For vintage rod and reel images I use my smaller 8.1 MP Canon SLR and shoot Jpgs, adjusting them as needed in Photoshop before posting on the web. Last summer I re-set this camera's Preferences to +1 for Contrast, Saturation, as well as Sharpness. I found that this setting produced crisp colorful Jpg images, ready for posting without much additional adjustment in PS (see Photo Topic 13).

Ebay Sets New Rules for Image Size

This April ebay adopted a new policy requiring photographs to be at least 500 pixels in the long dimension, and they recommend that photos be at least 1000 pixels in the long dimension for best viewing and enlargement in their listings. (Craigslist has similar guidelines.)

When Bigger is Not Better !

Using my camera settings from last year, I found I was creating original Jpg images of 3600 px x 2400 px. Although I re-sized these images to 1600 pixels before uploading them to ebay, I realized I was working with these large 3600 px images in Photoshop, slowing down image adjustment in PS (and in other editing software). Also I was filling up my hard drives with needlessly large files. [Since I often use Adjustment Layers in Photoshop, requiring files to be saved as Tiffs during the adjustment stage, my saved files became quite large indeed, up to 46 MB!]  And during shooting these Large 3600 px Jpgs were filling up my camera memory cards too!

Camera Options

Since I wasn't planning to print any of these images, the largest size I needed for them was the ebay size (1000 px recommended). To ensure excellent viewing quality I conservatively chose 1600 px (longest dimension) to upload.  [This size also allows me to use these images later for other purposes on the web – More on this later in upcoming Part II.]

Camera Menu.  Checking the Menu on my Canon 20D I found three Image Quality options which control image size: Large (3500 px), Medium (2500 px) and Small (1700 px). I then changed the setting from Large to Medium (2500 px), and my saved file sizes, even when using Tiffs for adjustment, went down from 12–23 MB to 8-14 MB; saved Jpgs were reduced from 4-7MB to 1.5-2.5 MB, even before re-sizing for ebay. And the 2500 px size of these images still allowed me to crop if needed, while still having final images of 1800 px --- almost twice what ebay recommends. [For future ebay photographs when I don't expect to crop very much, I can further reduce the Camera's Quality setting to Small, and still have “high quality” 1700 px ebay images - and eliminate the re-sizing step!]

Other Cameras.  Checking another camera for comparison, my Canon Power Shot A-590, Quality options are: Large (3200 px), Med 1 (2500 px), Med 2 (2000 px), Med 3 (1600 px), and Small (640 px). Here all the above conclusions apply, ie Choose Medium 2 or Medium 3, depending on whether you plan to crop, and upload your Jpgs directly to ebay.

Take Home Conclusion:

*** Set your camera to record Smaller Image Sizes when you don't need bigger files.  You will save time and space!  (Do this in Camera Menu under Quality.) ***


[Next Photo Topic: Digital Images – How Big is Big Enough? – Part II.  Image Sizes for Viewing on Computer Screens, Digital Projectors, and Printing Business Cards]

Questions or Feedback?

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Photo Topic 13, October 2013 – Digital SLR Camera Preferences – Contrast, Saturation, Sharpness – Part 1

This summer I photographed vintage fishing equipment to list on ebay and Craigslist. I wanted to create very good images, but do it in the shortest time possible.

Shooting Jpgs

When I shoot images professionally, I use a Canon SLR and shoot RAW format (+ large Jpgs for backup). I process the RAW images using a raw converter - Adobe 'Camera Raw' (part of Adobe 'Bridge') or Canon's 'Digital Photo Professional'. [Adobe 'Lightroom'  would be another option.]   I then take the images into Photoshop for final adjustments and sharpening.

[ RAW format maximizes accurate recording of the subject's full range of tones and colors, but processing RAW files takes time. For my ebay / Craigslist images I wanted a shortcut, so I shot Jpgs and planned to use them directly.]

First Attempts

Automatic Modes  If ever there was a good time to use an automatic mode, this was it!  I chose Program mode on my digital SLR, hand held the camera, and began to photograph the first fishing reel. [See Photo Topic 11, Easy Summer Photos II, for a description of my background set up and lighting.]

Program is the automatic mode that does a good job of balancing shutter speed and aperture, given the level of available light. It also allows you to set the ISO, or “film speed”, which is always an advantage. Since I didn't need super high resolution for web posting, I opted for ISO 800. [See Photo Topics 6 & 7 for a full discussion of automatic camera modes.]

First Images

The first images were (how should I say this)... disappointing. Using available daylight indoors, even with ISO 800, the camera selected a slow shutter speed (1/25th sec) and a fairly wide aperture (f4 – 5.6). The large aperture was not giving me the depth of clear focus I needed, while 1/25th sec was borderline for hand holding.

Change to Av Mode

Needing a smaller aperture, I switched to Av mode [auto mode where you to select the Aperture, and the camera sets the proper Shutter Speed.]  Setting the Aperture at f16 for good depth of field, I started again... and saw I still had a problem!  Though I had good depth of focus, the shutter speed was a sluggish ½ second!!! Not fast enough for hand holding, even with the camera braced on the nearby chair!

I had two options: move outdoors for brighter light, or get out my tripod.  Already having beautiful light inside, I chose the tripod.

Third Time's a Charm

Once again I started shooting, using tripod and cable release, and found I was making good sharp images with good depth of field. I finished the shots, took the memory card to the computer and quickly uploaded the Jpgs to Craigslist.... Well, not so fast! --- I had good sharp images, but the Jpgs lacked Contrast and Saturation (and needed additional 'Sharpening' too). Easy to fix in Photoshop, I thought...  BUT my goal had been to save time by using the Jpgs directly!

Fig 12-1  Original Jpg w/ low     Contrast & Saturation

Fig 12-1  Original Jpg w/ low Contrast & Saturation

Setting Camera Preferences

Many modern digital cameras, besides offering different advanced Camera Modes (eg Program, Av, Tv, Manual) and a choice of ISO for that mode, also give you a choice of how you want the camera to process your images – these choices are called Camera Preferences. Among these Preferences are a set of image characteristics or Parameters including Contrast, Saturation, and Sharpness. You select the level for each you want, and then that level is automatically applied by the camera to each Jpg image.

[On Canon SLR cameras, Press the Menu button, Scroll down to Parameters, and Select it to see two choices ('Parameter 1' & 'Parameter 2'), as well as three programmable custom choices (called 'Set 1', 'Set 2', 'Set 3' in Canon cameras). The level of each image characteristic (ie Contrast, Saturation, etc.) can be set from a 5-point scale, from -2 on the left, and +2 on the right.]

Selecting Parameter Values   Among the choices in advanced camera modes are a set of values called (in Canon cameras) 'Parameter 1' in which Contrast, Saturation, and Sharpness are all set to +1, resulting in more vivid images. Selecting the 'Parameter 2' set brings all values to '0', for softer and more natural images. ('Parameter 1' values are often the default for basic Auto modes in SLR cameras, and for almost all modes in 'point and shoot' cameras.)  By choosing between 'Parameter 1' and 'Parameter 2' sets in the camera Menu, you can easily control the Contrast and Saturation that will be applied by your SLR camera to your Jpg images.

In the above example from 'Easy Summer Photos', it is now easy to see why my first Jpgs of a vintage fishing reel (Fig 13-1) lacked Contrast and Saturation. In the Camera Menu I had selected 'Set 1', with values of Contrast -1, Saturation -1 and Sharpness -2, a good setting to use for Photographing Artwork where the images will be taken into Photoshop for further adjustment. To correct the problem I changed my choice to 'Parameter 1', where the values for Contrast, Saturation and Sharpness are all +1The next Jpgs of my fishing reels were brighter, more saturated and sharp! (Fig 13-3)  And when I uploaded them to ebay, they were more likely to catch your attention!

Figure 13-2  Jpg w/ Contrast +1, Saturation -1

Figure 13-2  Jpg w/ Contrast +1, Saturation -1


Fig 13-3  Jpg w/ Contrast +1, Saturation +1      

Fig 13-3  Jpg w/ Contrast +1, Saturation +1  

In Part 2, we will discuss Contrast and Saturation in more depth, what Contrast and Saturation levels are best for different photographic subjects, and how to set your own Custom Levels for Contrast and Saturation in Jpg images.

Questions or Feedback?    If you have Questions or Comments about this or any previous Photo Topic article, please send me an email.  Thanks.


                                                                                                 Artist Credit: top of page - Passiko True, silver, 2010