Alley in Pisa, Italy

by Lars Kotthoff

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13

Reasons to use the memory card: A good card reader will be faster than your camera's data cable (a cheap card reader - not so much) When you use the camera data cable you also use the batteries, I had an old camera that really drained the batteries when using the data connection (a set of batteries lasted a few days of shooting or about 30 minutes of data ...


8

.CTG files contain image catalog information that is used by the camera when managing and displaying photos. You'll probably find a .ctg file for each set of images created. The .CTG files should get deleted automatically when the associated images are erased, although it seems that current best practices are to format the memory card often so I wouldn't ...


6

Sorry to say but you are confused. I suggest you read this article about resolution. I wrote it a long time ago but it still applies. The resolution of a RAW file and a JPEG is identical unless you scale it down. Processing a RAW file does not affect its resolution. If you save it as TIFF, you can get the same color-depth too. If you save it as JPEG, then ...


6

It's a thumbnail file. Usually it's generated when you take a video, to give you a preview image on the LCD and to store the EXIF information for exposure, focal length, etc. You can rename it to .jpg if you want to view it on your computer.


5

PNG compression quality varies greatly from compressor to compressor. The standard PNG compression in Photoshop for example can sometimes commonly be beat by large percentage points. This is primarily due to more intelligent switching algorithms when it picks the kind of prediction to do for a certain set of pixels. Most of the "additional" compression is ...


5

Use Lightroom's Synchronize command. You can execute this command at whatever level in your catalog is most appropriate, and you will have the option to remove all missing files which, if you have already intentionally deleted your image files, is what you want.


4

Canon has a detailed manual available for the Wifi functionality of the 6D. You can both remotely operate the camera with EOS utility over Wifi and share photos with computers or smart phones. You can also do remote shooting from a smart phone.


3

It sounds like MacOS is just creating a disk image file (.dmg I would guess) for the USB drive, which can then be mounted. I'm curious if you can actually clone an SD card, or just USB drives...SD/CF cards are usually treated differently than USB drives, and the MacOS clone feature is usually intended as a means of backing up literal external USB drives. ...


3

The DPI reported in a JPEG file is just a metadata field. That is, it's intended to offer a hint to software that displays or prints image files, but it's not immutable, in practice it's not authoritative or enforced, and it's usually ignored by most software and photographers alike. The actual DPI of a displayed image is determined by the absolute ...


3

Besides the algorithms described in other answers, small images' file sizes can be reduced by stripping out metadata from the file. EXIF/IPTC data can add up to 64 kilobytes to a JPEG image.


3

The AVCHD directory is for video files. I asked a similar question on another site (can't find it at the moment though). But it looks like you've gotten the gist of what they do. Wikipedia's page on AVCHD lists this structure as well: Not sure where there is an official reference though.


3

If you are moving from iPhoto to Lightroom, you might need to get yourself accustomed to a simpler form of organization. Outside of faces, which is currently lacking in any automatic form (you can manually add tags for people or families and search by those), it is one of the top requested features for the next release of Lightroom. For the rest, such as ...


2

Firstly, DPI really isn't a unit of resolution, but one of dot density. For example, you can have a 300x300 pixel image and print it at 300dpi for a 1 inch x 1 inch print, or you can print it out at 100dpi for 3 inch x 3 inch output. In both of these cases, the image's resolution (300x300 pixels) remains the same. As for compression: The most common ...


2

Any better way of doing this? Yes: delete them from within Lightroom, which will remove them from the Lightroom catalog and gives you the option to delete from the filesystem. To fix this, you can just go to Lightroom and find the file(s) you deleted and delete. You'll be warned that the file can't be found, and can just proceed.


2

I did a quick google and found this: FAQ: Sending images to a computer (Wi-Fi function) (EOS 6D) which is a very detailed step by step procedure for transferring pics to a computer. But I also came across this post: 6D WIFI: how long for RAW transfer?(dpreview.com) which references The New Canon EOS 6D – Welcome to the Full-Frame Club! which says: ...


1

Yes, you can do this. But this will drain the battery a lot quicker, so keep spare ones ready! When you are connected to remote shooting more from the PC, the photos captured are directly transferred to the computer instead to writing to the SD Card.


1

I haven't had much luck recovering the raw files themselves, but I've seen several instances of problems like this where I was able to extract the JPG preview that's embedded in the RAW file. Believe it or not, the best program I've found for grabbing these JPGs is Irfanview - a great little free tool. Any JPG you grab in this fashion won't be of the same ...


1

I am a computer scientist and photography is my hobby. All the answers provided information of "traditional" compression algorithm. I should point out that there is a new algorithm that can shrink a JPEG 4x to 6x in file size without losing quality. This new compression method is specifically designed to shrink JPEG photographs. This means that ...


1

I believe that all of the items you noted are stored in a proprietary format specific to iPhoto with one exception: location information can be exported. Exporting the location information should write the GPS data to the photo's metadata; Lightroom should then be able to read this data on import.


1

Just based on the "THM", I'd guess it's a thumbnail of the picture. I haven't looked specifically at the 550D, but in the cameras I have looked at, it was really just a small JPEG with a somewhat unusual name. As far as what it's used for, the camera loads it when you're viewing pictures on camera. Only when/if you zoom in does it load the full-resolution ...



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