class SomeDjangoModel(models.Model):
    tiny = models.ImageField(upload_to=image_path('tiny'), blank=True, null
        =True)
small = models.ImageField(upload_to=image_path('small'), blank=True, null=True)
medium = models.ImageField(upload_to=image_path('medium'), blank=True, null
    =True)
press = models.ImageField(upload_to=image_path('press'), blank=True, null=True)
Динамический путь загрузки – включить исходное поле