When designing Arsenal's photo review, our goal was to allow users to browse photos on the DSLR or mirrorless camera as easily as they can review photos taken with their Apple or Android phone.
While transferring large photos from another device will never be as fast as a built-in camera, Arsenal's photo review is surprisingly snappy. To accomplish this, we do a few tricks to make things more responsive.
Reviewing New Photos
As soon as you take the shot, Arsenal grabs a low resolution version of the image from the camera. This is sent to the phone app and is available within 1/2 a second.
Next, the Arsenal unit downloads a full resolution file and creates a JPG preview that is the size of your phone screen. This usually shows up in the app at around one second after the shot. Finally, a full resolution JPG (converted from RAW if you're shooting RAW) is sent to the phone. This usually takes about 3 seconds.
Reviewing Existing Photos
Arsenal also allows you to review existing photos on your camera's memory card. When the Arsenal app detects a card with existing photos, it will begin caching preview images. This process can take a significant amount of time, since Arsenal must process each full-resolution image file.
Once the caching process is complete, you can review these photos normally using the app. You can also review photos while caching is ongoing, but the images will be slower to load and app performance will temporarily be degraded.