round Leitz hoods with rectangular fronts, howto DIY?

[CrisR]

Outside of using an ABS injection moulding machine, which would require tooling etc, this is the best/cheapest way of producing a hood at this level of accuracy, that fits properly on a bayonet, out of a material that can actually be used in the real world.

I do a lot of mould making and casting in liquid plastics and resins, and at these thicknesses, not only would moulding the mount be very hard, but the resulting cast would break easily.

They'll never be as robust as an OEM plastic or metal hood, but they seem pretty damn good, better than i expected really.

 

[johannielscom]

Ha!

Never my intention to see this materialize as a product like this but it sure is nice to see this!

CrisR, I'm thinking you better get in the game now with things like this, and you can have a lot of successful sales before everybody catches up! There's money to be made here, I'm sure.

Great job!



Thing is, that in the (now sadly removed from YouTube) video, the widow of Ravilious showed hoods that were in fact oversized and had a part of their too-big fronts masked off with tape, creating a rectangle that corresponded with the 2:3 aspect ratio of the film. As a result, there was a lot of darkness inside the hood and the image that was recorded by the lens gained a very specific clarity and definition from that. Just review Ravilious's work and you'll see beautiful low-contrast, high-sharpness pictures.

Shots that were created with those over-size hoods and prewar uncoated glass.

 

[dave lackey]

Ha!

Never my intention to see this materialize as a product like this but it sure is nice to see this!

CrisR, I'm thinking you better get in the game now with things like this, and you can have a lot of successful sales before everybody catches up! There's money to be made here, I'm sure.

Great job!



Thing is, that in the (now sadly removed from YouTube) video, the widow of Ravilious showed hoods that were in fact oversized and had a part of their too-big fronts masked off with tape, creating a rectangle that corresponded with the 2:3 aspect ratio of the film. As a result, there was a lot of darkness inside the hood and the image that was recorded by the lens gained a very specific clarity and definition from that. Just review Ravilious's work and you'll see beautiful low-contrast, high-sharpness pictures.

Shots that were created with those over-size hoods and prewar uncoated glass.

Yes! This is sweet!

Can you do a black or chrome color version for the Summarit 1.5 ? My M3 is screaming for a nice hood but the original is rather "not"-elegant IMO and expensive!:angel:

 

[yossarian123]

this has been one of the nerdiest threads of all time. I love it!

 

[Rob-F]

Should we start listing lenses for CrisR to make these hoods for? I could start with the XPAN. Replacement hoods for the 45mm and 30mm are hard to find, and are unnecessarily expensive!

Then there are the CV wide-angle lenses. The 25/4, 28/3.5, and 35/2.5 just have those little short metal rings. The Hasselblad 60mm CT* has only a round hood. Just for starters . . .

 

[CrisR]

Thanks guys!

Given the right dimensions and FOV from the hood mounting point, i can make any hood you like🙂

I figured this would be a good test as it fits 3 different lenses.

With regards colours, it's very limited and i'd probably be going with the whole "production on demand" setup, meaning they wouldn't go through me but be sold direct, but i am thinking about sanding back and repainting the surface of mine black, so i can certainly provide some video tutorials on how to do that for any hood on any lens 🙂

Bayonet is the easiest. Screw thread can be done, with a donor filter as you can't print threads - then it'd be up to you to line it up correctly! The other way would be to do more of a thumb-screw affair, where the hood comes with a space to glue in, on the inside, a standard M3/M4/M5 nut and use a regular bolt to apply compression to the lens. I was thinking of doing something like this for the CV 21mm and 25mm lenses i own as a test

Main thing is, it's all good fun 🙂

 

[Rob-F]

The old 60mm Distagon CT* I was referring to takes a hood that threads into the filter threads. How about a hood made of a rubbery material that would just force-fit over the barrel? Might work for some other lenses, too, and simplify the attachment method.

 

[CrisR]

Don't really have the ability to produce in a rubbery material i'm afraid.

 

[Livesteamer]

Noctilux hoods are crazy expensive. I'll bet you could make money selling some. Very cool project shown here. Thanks. Joe

 

[CrisR]

well, i'm not looking to produce knock-offs, but i've no problem producing a hood in a style that's not available on a lens - something similar to this for the Nocti should be no problem if there's demand for it? 🙂

 

[CrisR]

Now that i know the method works and the materials are suitable, i've moved onto the next stage, a bit of optimisation

I've put together a spreadsheet that allows me to tabulate the ideal rectangular opening for a given focal length, at a given hood depth, for both full frame and M8 crop sensors.

This means that the M8 hoods can be smaller for those that aren't using full frame. It also means i can offer shorter and longer versions depending on what people want.

I wanted to be quite liberal with the initial hood i designed and had made - it had an opening of 52mm x 42mm to accommodate the widest 35mm lens with some room to spare. As it was, this caused some finder blockage.

From my table data, the exact rectangles should be:

M9: 42mm x 28mm
M8: 37mm x 25mm

and for the 50/2 Planar you can get away with

M9: 35mm x 24mm
M8: 32mm x 22mm

So for the 50mm on the M8, the opening really doesn't need to be 52mm x 42mm...

Needless to say, this suggests some very interesting hood designs, even with a generous 10-20% extra as a safety margin across focus distances...


Another example of this spreadsheet is for the CV 21mm f4. For a similarly deep hood, you're looking at

M9: 39mm x 26mm
M8: 30mm x 20mm

Which i'm pretty sure is a lot smaller than the LH1 hood...

I was thinking of having a go at some rectangular hoods more like the Fuji ones, as to make the opening wider than the 43mm filter size, you'd have to make the hood at least 25mm deep on the M9 35mm and 35mm deep on the M9 50mm. Which seems excessive.

I'll have a better idea once i've done a bit more modeling.

 

[CrisR]

Oh, and of course, smaller hoods mean cheaper to print hoods! 🙂

 

[Sejanus.Aelianus]

I'd like to thank you, Cris, for triggering me to order a 3D printer and get on with learning a CAD/CAM language, a project I've been toying with for a couple of years.

I doubt I'll be in competition with you for quite a while, though!

😀

 

[ChrisC]

Has anyone tried 3D printing lens hoods of this type? .......?

What a fantastic thread, I'm glad to have stumbled across it. I've long thought that round lens hoods are lazy-design, expensive afterthoughts for lens manufactures. And yes I'm aware of the James Ravilious film where his widow demonstrates his early, uncoated lenses [masked for shooting into the light with retained open shadows].

3D printing is an amazing technology. I've come a bit late to this discussion, but here is a hood sent to me by Bo Lorentzen in Los Angeles :

http://bophoto.typepad.com/bophoto/2010/09/new-lens-hood-for-voigtlander-35mm-14.html

As you can see, it's 3D printed and I use it on my a Zeiss C-Biogon with an M8. I find it a fantastic hood and I've been using it for a couple of years. The slope of the rectangular shape is perfectly aligned with the viewfinder so that only a very thin line shows in the viewfinder, and the cut-out means the lens does not lose any of the bottom right hand corner when framing. A black, elasticated slip-over cover to keep dust bunnies off the lens would be great, but I've not found a solution yet.

Here's a variant on the above :

http://bophoto.typepad.com/bophoto/2010/12/m8-zeiss-28-biogon-hood-keep-it-tight-.html

Bo used to be active on LUF, but I've not noticed his posts for some time.

ChrisR, I hope you persist with your project. And yes, I too think those Fuji lens hoods look good. However, a true rangefinder hood needs a good cut-out, and a sloping profile of the rectangle to ensure minimal framing intrusion. Good luck.

.............. Chris

 

[rodt16s]

I'd be interested in a hood for my Summilux 35mm v1, I do get concerned about losing the std OLLUX hood (mega-bucks to find a replacement)
Just one question about the material, how inert is it..? i.e. does it outgas anything that will effect the glass or coating over time..?

 

[CrisR]

Here is the newly optimised version of the Nokton 35/1.4 lens.

I've kept the mount and the length the same as the version i had prototyped, but i've used my new hood calculations from my spread sheet to work out a far tighter, more accurate hood rectangle.

I made sure to oversize the rectangle by 10%, but i can easily bump that up if need be. As you can see it's a fair bit smaller and won't enter the viewfinder nearly as much as the last version.

I've also put a comparison between the previous version and this.

 

[burancap]

Great work! I have really enjoyed this thread as it has developed!

 

[Brian Legge]

Very nice!

Does that design take into account a filter mounted? Thats a big deal for me as I often use a yellow filter.

 

[CrisR]

And here's the new compact version for the Zeiss 50/2 Planar, once again, with a 10% wider opening.

It's on the 35mm body model, just for ease, obviously the Planar is longer than that.

 

[CrisR]

Very nice!

Does that design take into account a filter mounted? Thats a big deal for me as I often use a yellow filter.

Yes, i've made sure that they can all take a filter as i use an M8 with a UV/IR cut so it's not much use to me if it can't! 🙂