DIY shaped bokeh filter questions

[lokisbong]

So I decided to try and make a shaped bokeh filter.This is what I got.

3-3-2011 by lokisbong, on Flickr
So a question? The outer stars seem to be getting cut off. Does that meen I need to make the “star” cutout smaller or larger? I have lots of the black materiel left to make it over.
Here is a picture of the actual doodad.

bokeh filter by lokisbong, on Flickr

[ennuipoet]

Well, I know what I won’t be doing this week 🙂

[lokisbong]

Why not? I won’t complain too loudly if you get more votes than me. lol.

[ravnostic]

I think the cut-off effect has to do with the light coming in from the sides hitting the edge of the lens frame; smaller would be better in that regard, as the stars could be closer to the edge of the frame; other than that, ‘crop’ comes to mind…

[lokisbong]

Thanks ravnostic. I kinda thought it might be smaller would do better. I would rather remake the filter than crop. seems to me like I would have to lose almost half the image to get rid of all the partial stars and that’s just not acceptable to me. lol I will try remaking with a bit smaller cutout and see how it goes.

[lokisbong]

Ok I made one with a few mm smaller hole and it seems to have less cut offs. Still a bit on the very outer edges but not bad. I did some searching on the webs for diy things like this and it seems to be a problem in more than half the pictures I looked at. I think the biggest challenge now is getting nice smooth edges on my cutouts. Every little flaw in the cutout shows up clearly in the picture.

[sleeping]

Stopping down the aperture on your main lens might make a difference as well – you often see elliptical bokeh towards the edge of the frame when shooting wide open, and that looks kind of similar?

[lokisbong]

I decided to experiment and it only makes the cut off worse after about 2.2 plus has the disadvantage of making the edges even more fuzzy looking like I did an even worse job cutting out the star.

[EdenLiesObscured]

for mine, i made a barrel that slides over the lens. sealed it with black electrical tape.
a bit cumbersome sometimes for focusing, but i don’t have to worry about light leaking in from the sides.

[lokisbong]

for mine, i made a barrel that slides over the lens. sealed it with black electrical tape.
a bit cumbersome sometimes for focusing, but i don’t have to worry about light leaking in from the sides.

I made my new and improved filter with a better fit to the uv filter ring and don’t get any light leaks and it is as easy as can be to use manual focus. I could make it even less likely to have leaks around the edges if I had another screw in ring from a different uv filter to act the same way the ring that holds the glass in place in the first place. I guess I could try to take apart the uv filter and put the cut out where the glass bit is now but I kinda like the little extra protection leaving the glass in affords.

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