What's the original image size?
The image that I load in is 640 x 360
Create a sequence from one of the images. Right click on an image in project and select "new sequence from clip". It would create a sequence as per image res.
when I am in the export window. Do I select the format to be Mp4 - or H.264 ?
You can try both. H264 has many presets for many different devices.
When I select .mp4 – the file pixellates when the cross dissolve – then the still image appears low quality.
When I select h.264 it seems to render fine.
Do you know what might be causing this issue ?
That's becuase mpeg4 has two presets but of quite low resolutions.
H264 is best for you .