I have not seen this. Can you give us the precise file name. If it is something like IMG1004.jpg and so on it should work. Please show us a screenshot of your Import window with the files selected.
Also, I'm not sure what you mean by double frames.
Hello and thank you for replying so quickly - I enclose a screenshot of my attempt to import the images, and, by double frames I mean importing two copies of each frame sequentially which the documentation led me to believe was achievable by changing the Import Prefs (again, screenshot included) to however may copies are required.
It looks like import as sequence is selected. Are you saying that when you do this you do not get footage?
If you uncheck JPEG sequence and import all files in the folder then you should get a bunch of JPEG files in your project panel. You can then select them all and create a composition from the sequence. Then, set the in and out point to the first frame and sequence the layers to create your movie.
Everything looks normal here. Are you new to AE? I'm still not sure what you are trying to accomplish.
Thank you for your help, I used AE about 8 years ago (with whatever the version was then) to do what I'm trying to do now, basically pull in stop frame image animations shot on green screen and string them together etc. (Sequencing the layers is a helpful way to achieve what I need so I'll use that way of working). Thanks again and I'll just list here what I was encountering!
So contrary to the AE documentation, I'm finding that...
1). If I uncheck JPEG sequence, I have no footage option but selecting them all brings them in as list of unconnected jpgs as you say into the footage window (in doubles in this instance as per Prefs).
2). With JPG sequence checked, there's still no footage option and though it comes in as a sequence it's a single copy of each frame.
3). With PSD files, the footage, composition and layered composition options are available
You can still Import your jpegs as a sequence AND make them two frames long in your comp.
Once imported as an image sequence, go to the Interpret Footage settings, and set the frame rate to HALF the frame rate of your composition. Working in a 59.94 comp? Interpret the image sequence as 29.97 fps and life is good.
Assuming the entire sequence needs to be chroma keyed, it would prove to be a lot easier -- you just key the one footage clip.
You are actually misinterpreting the documentation. If you import an image sequence, no matter what the format, you get a single item in the Project panel that is a movie made from your image sequence. The frame rate is set automatically at 30 fps in your preferences but you can change that using File Interpretation. To import an image sequence you simply click any image in the sequence and check the image sequence box. It works the same for all formats.
If you uncheck the image sequence check box then you only import the images you select. If you select all images in the folder then you get all images. They may or may not come in in the right order. It depends on the file name. You can drag all of these images into a new comp and trim the length of the images, then sequence layers. This usually is a very inefficient workflow. Working with a movie is a lot easier.
As Dave said, you can change the frame rate be selecting your image sequence in the Project Panel and then right click or go to File>Interpret Footage.
Thanks for the tips Dave & Rick, I appreciate it and I will follow your advice! (Sometimes however many times you read the documentation it still feels unclear).