hello,it can fit sigma contemporary 150 600mm.the compartment inside the backpack is removable, you can DIY according to the size needed. 

Look on the lens and it will tell you the size of the filter required,. 

The V50x comes with a skeleton case with a slotted rear door replacement, but there is no opening to allow plugging in an external mic. As a note, the sound recording, even while in the completely waterproof case, is better than I had expected. If you're not worried about moisture, there is a threaded tripod mount on the bottom of the camera and an adapter that will allow you mount the camera without using the case. 

hello ,you can use ie take picture of the sun, but not for the solar eclipse 

Cheers.