Dimensions of a lens hood - making your own

[Italian4215]

I want to make my own lens hoods. How do I figure out the appropriate dimensions for the hood? I assume there are different formulas for petal, round, and rectangle hoods.

[cicopo]

You can try making your own if you want but all things considered if aftermarket hoods are available at sane prices why not go with them? According to your message you have 2 lenses & there are hoods listed here for them .

http://www.procameragear.com/catalog/index.php/cPath/64_65

(and I've bought from them because they support another forum I belong to) plus I'm sure there will be options through Ebay. The primary consideration in their design is to shield the lens from stray light BUT not to interfere with the full field of view the lens must cover at the wide end if it's a zoom, or at it's design FOV. for a prime.

[Italian4215]

Thanks for the information. $12.95 a piece isn't bad that is roughly $30 after tax and shipping. I was going to print out a template using this website on hard card stock, cut it out, form it, and then fiberglass resin it, dry, sand to smooth, and then buy carbonfiber sticker and apply, then apply clearcoat on outside and mate black inside.

[cicopo]

Well you could do all of that but unless you already own the materials I think it's going to cost more than ready made ones that fit properly & can be reversed for storage / lens cap installation. I say this as someone with a lot of experience working with fiberglass and who has fabricated many things using it. Here's the link to a DIY project for my underwater camera.

http://plus.google.com/photos/116179596240613012497/albums/5161077059071628785?banner=pwa

And this is a slightly bigger project I'm working on (it's my day job).

http://plus.google.com/photos/116179596240613012497/albums/5352917643688876417?banner=pwa

[ebiggs1]

Being involved in astro-photography, we make lots of "lens hoods". But your way is going to cost you as much as buying the real deal.

Try you local Hobby Lobby and see if they have cardboard tubes of the correct size you need. They can be cut to whatever shape you desire.

[Italian4215]

I want it to be sturdy hence why I was going to use fiberglass resin. I have all the materials needed cause my father just finish re fiberglassing a sailboat. My main concerns are the dimensions of the hood and how I will attach it. I've heard of people using an older filter with the glass poked out, but not sure if I want to afix it like that.

[ebiggs1]

Yes, that is one of the tricks we use a lot. Old filter rings are good stuff. The cardboard tubes will let you trial and error a hood. Than you can make a "solid" one from fiberglass. I do not know why you want to but hey go for it. Might be fun to play with.

[Italian4215]

How do you go about getting the right dimensions for say a petal hood? How big/long to make the petals, diameters, etc. ?

[ebiggs1]

Trial and error! Shoot a white sheet and see if it interferes (vignettes).