Thumber: Frequently Asked Questions


  1. I have unzipping software, and have downloaded Thumber's zip files from your site. However, it gave errors when unzipping. I downloaded a second time. WinZip indicates the result is not a valid archive and suggests another download. Am I doing something wrong? Is there another source? I tried two different zip programs (one DOS and one Windows version). What's the problem?
  2. Unfortunately, some browsers have a hard time successfully downloading files from Thumber's main site. You can try downloading from Thumber's alternate location, or search for an alternate location at, or the SIMTEL archives. (Note: You may also need the VB6 runtime files.) Also, see the answer to the last question on this page.

  3. What do I do with a "zip" file? When I try to open the file it, I get a message box asking what program I want to open the file with. What gives?
  4. You need to use unzipping software (such as WinZip) to extract Thumber's installation files. There are many resources on the internet explaining how to unzip an archive, extract the contents and install software. CNET has some easy to understand instructions. Also, see the answer to the last question on this page.

  5. What version should I download...Full or Lite? What's all this about Visual Basic files? Do I need them? Why? Where do I get them?
  6. Here is a more complete answer, but the simple answer is get the full version and you'll have everything you need. Don't worry about the Visual Basic files any more!

    Installing, Registering and Upgrading

  7. What is the best way to upgrade my old version of Thumber to the latest release? Download the full version and reinstall over my current version??? or........
  8. The best thing to do is download the lite version (you already have the VB6 files that are in the Full version), uninstall your old version, and then install the latest version.

  9. What features are turned on if I register Thumber?
  10. The limit on the number of images that can be processed in a single session is removed.

  11. If I register how long do I have to wait to get the code?
  12. You should get it almost immediately, and certainly within 48 hours. If not, send me an e-mail.

  13. I just registered...where is my code?
  14. The code should have been sent to you by Kagi, the service that I use to process payments. They send a detailed e-mail, and the code is down at the bottom. Keep scrolling!

  15. I got the code, but it isn't a valid doesn't work.
  16. All the codes are tested for validity before being sent. Make sure that you enter all the characters exactly as they appear in the e-mail...Don't confuse the letter "O" with a zero, the letter "l" with the number "1", and so on. Also, make sure there are no extra spaces before or after the code. If you are still stuck send me an e-mail, but it is very unlikely that the code is invalid.

  17. The code worked last time I installed Thumber, but not this time.
  18. If a code worked once, it will always work. You are probably either not entering it correctly, or have some system problem that is preventing Thumber from validating the code (try rebooting!). If you can't get your original code to work, chances are good that a new one won't help either. Codes don't expire or "go bad".

  19. I recently registered and paid for my copy of Thumber. What is your policy on updates?
  20. All updates are free for registered users. Your registration code will work for all future releases.

  21. Can I get Thumber in Spanish, French, German, etc...?
  22. No...Sorry.


  23. Do you have any information about the exif and or jpeg file format?
  24. Only the freely available documents I've picked up off the internet. Wotsit has some general stuff about JPEG files. An "EXIF" (Exchangeable Image File) jpeg is the same as a "regular" jpeg file except that it contains some extra information about image data. This data is placed in a special field (usually) at the start of the file and contains all the data. Other than this, there is no difference.

    For a long time, there was no freely available documentation on the EXIF format. However, recently the Photographic & Imaging Manufacturer's Association (PIMA) has made the complete EXIF 2.1 File specification available. The TIFF/EP specification written by ISO TC42 WG18 of PIMA used to be the only reference available, and still has some useful information. A (slightly) easier document to read is this great summary written by TsuruZoh Tachibanaya.

  25. I've found a bug: Thumber reports the whitebalance as "unidentified" when the camera is set to "auto". Can you fix this by renaming unidentified to "auto"?
  26. Thumber simply shows what the EXIF data reports. Choose File|Image Properties to see the unaltered EXIF data as recorded by your camera. You'll see a line like this:

         0x9208 0x01BA 0x01C2 LightSource = 0

    If you look at the EXIF tag specifications, (See page 48 of, you'll see that the EXIF codes for lightsource (aka whitebalance) translate as follows:

         0 = Unidentified
         1 = Daylight
         2 = Fluorescent light
         3 = Tungsten Lamp
         10 = Flash

    Nikon cameras, in particular, seem to be a little flaky in their reporting of whitebalance, and report 0 for settings such as "flash" and "manual preset". Thus, renaming "unidentified" to "auto" would create a problem...Thumber would always report "auto" even if the whitebalance was preset, or the flash was used, etc...

  27. What is Brightness EV? usually the values of Exp. Value EV and Brightness EV are the same but sometimes not - why is this?
  28. Thumber reports Brightness EV to measure the brightness of the scene as measured by the camera's light meter. If the camera is set to ISO 100, and no exposure compensation was used, then the Brightness EV and Exposure EV should be the same value. If the film speed changes or the user sets exposure compensation to something other than zero, then Brightness EV and Exposure EV will vary. See Note 20.10 of the photoforum FAQ for a more detailed mathematical explanation.

  29. Thumber looks like an excellent program, but doesn't seem to include some of the information I want about my "Brand X" camera images. Why not?
  30. There are two likely reasons. First, your camera may simply not record this information. Many Sony cameras fail to report focal length, for example. Second, your camera may record this information in a proprietary format that Thumber cannot read. There is an area in the EXIF header where manufacturers can record information in an undefined format. Many manufacturers (such as Nikon, Canon, Casio, Fuji, Olympus and others) record data here in a format for which there is little or no published information. Thumber can decode some of this information for some cameras if it appears to follow a standard EXIF format, but much of this data is unreadable. Here's what I've been able to decipher of the Nikon-specific information. If you have any more details send me an e-mail.

  31. I have noticed that thumber reports different shutter speeds compared with the Exif Viewer application included with my "Brand X" camera. For example one image was reported by thumber to be 1/69 whereas my camera's app reported 1/60. It appears that my camera's app always shows a standard shutter speed i.e. 1/60, 1/250, 1/500, etc. whereas Thumber does not round up/down? Please could you advise which is correct?
  32. I believe that Thumber is more accurate, but here is what is happening. Some cameras store shutter speed info in a different EXIF tag using a different method than most other digicams. Specifically, they use "APEX" notation. For example, such a camera might record a shutter speed of 880/100 in the EXIF data. To convert this APEX value into something human readable, raise 2 to the power of the APEX value, and then invert it:

    First note that 880/100 = 8.8, so
    Shutter speed = 1 / (2 ^ 8.8) = 1/446

    Why some manufacturers choose to "convert" these shutter speeds into something that looks more like a "standard" shutter speed is a mystery to me. Perhaps they think that people wouldn't believe/understand these "non-standard" values. In fact, the last time someone raised this issue I added a feature to Thumber to try and do the conversion as well. Click F9 (to bring up the options panel) and check the box marked "Use smart (i.e. non-formulaic) decoding for EXIF values...") then Thumber should "standardize" the values. I can't promise that it will always convert them to the same values that your other software does because I'm not sure how it handles rounding up/down, but it should be close. In any event, I don't think any "rounded" value will be as accurate as the actual value!

  33. Is adding or removing a comment a "lossless" feature? Does this degrade the image quality in any way?
  34. Yes, this is a "lossless" feature. You can add and/or remove comments repeatedly with no effect on the image quality.

  35. Are the comments that Thumber can add to images part of the EXIF data?
  36. No. There is a field in the EXIF data that allows for the addition of a "user comment", but Thumber doesn't use it. In fact, I don't think I've ever seen any software or camera use it. Rather, Thumber uses a more general JPEG comment field. This has the advantage of allowing comments to be added to any JPEG files--not just those that contain EXIF data. For more information on the JPEG comment field, there is some technical information at Wotsit. Here's a document that has some details.

  37. How about CIFF support? This is a format used in Canon A5 Zoom. Is it supported?... or ... will it be supported?
  38. No, and probably not! The CIFF format never really took off. In fact, I think the Canon A5 and one or two other Canons were the only ones to ever use it. Even Canon now seems to have abandoned it so I won't be adding it to Thumber.

  39. Are there are known limitations?
  40. Some users have reported problems using Thumber on non-English versions of Windows. In particular, Chinese versions of Windows seems to cause a problem. At the moment, I do not have a good solution for this issue.

    Other Problems

  41. I've found a bug. Will you fix it?
  42. I'll certainly try. I encourage users to report any bugs, and I try to resolve them all. Sometimes it is impossible for me to replicate the problem that a user reports, which is usually because my hardware/operating system/computer/etc. may be set up differently than yours. This can make finding bugs tricky. But I do investigate all the reports I get, and am able to fix most of them.

  43. I've got a great idea for a new feature. Will you add it?
  44. Maybe. I'll definitely read your idea, and consider it. I receive a lot of e-mails from people and some have great suggestions. I add some of the features that users suggest. However, many of the ideas that people suggest would be (in my opinion) of limited usefulness to most other users of Thumber and are unlikely to be worth the effort to implement. Thus, I can't add all the features that people request. Sorry!

  45. I e-mailed you, and you didn't respond. Why not?
  46. Because the answer to your question is either contained in this document or Thumber's help file. I respond to almost all the e-mail I receive. However, I frequently receive questions such as "what do I do with after I've downloaded it?" Having answered this several hundred times, I'm becoming less and less enthused about giving personal tutorials on how to download and install software. Please don't take offense if I don't respond personally, it probably means that the answer to your question is easily available by reading the documentation. I don't ignore any bugs reports or non-trivial questions.