Looking at buying my first batch of ND filters. Thought that a Hoya 3 stop and 6 stop would be a good start. My question is - can I stack these to achieve 9 stops using either a 24-70mm f/2.8L II USM or EF 16-35mm f/2.8L II USM.
I understand that the 16-35mm might vignette badly with stacked filters. Does anyone have experience with this ?
Also that many lenses you can't actually go up to 9 stops as wide angle lenses sometimes will give you an x in your image at much lower than 9 stops.
Help and feedback please. Maybe the slim B+W might be an option, but any better with vignetting ? Can u stack a hoya + a slim B+W on top (as I understand the slim B+W doesnt have the thread on top)
You do not get an X with regular ND filters (as you suggest stacking), whatever the focal length. Those "Maltese crosses" are exclusive to Variable ND filters as some of the member have mentioned.
I use the vaunted Lee system, but sometimes all you need is a quick reduction in light so you can shoot wide open. In that case. there is no real problem to stacking two ND filters, provided the following:
1. Buy good quality filters with minimal color cast- B+W or Heliopan, ideally. Top quality Hoya should be fine, too.
2. Make sure the filters work with your widest lens (in this case you're buying for 82mm filter threads, so that's fine).
3. Try to see if you can find slim mounts.
4. Make sure you have filter wrenches, cost only a few bucks.
5. Don't overtighten.
6. Expect some mechanical vignetting (no light due to the rim of the filters obscuring) up to 17-18mm, and probably some optical vignetting (reduced light due to reduced transmission in filter periphery) up to 20mm (probably correctable in post).
Now, if you find you are using 9 stops pretty frequently, or feel the need for graduated ND filters, then moving to the excellent Lee system makes a lot of sense. However, the Lee system is more bulky, expensive and the glass Big Stopper makes me nervous the minute I take it out of its tin.
So I would go ahead with the Hoya filters for now and maybe make a decision on the Lee system down the road if necessary.