Best material for DIY dew shield

[ianpwilliams]

I've got my camping mat. Does anyone have an idea of how long I can make my dew shield for my 1100D with it's default 55mm lens attached (and fully extended)? It has been suggested that I could make the dew shield in a funnel shape (kind of like those things dogs sometimes have to wear), which could be an option, but obviously I would prefer to make a straight tube if I can, because it would be a lot easier. I suppose if I went for the tube option then I could just make it long, and then cut it down a bit more each time until it doesn't cause a problem.

[Alien 13]

The diameter needs to be quite large to avoid vignetting i use this on my kit lens and the 50mm lens.

Alan

[peroni]

I've got my camping mat. Does anyone have an idea of how long I can make my dew shield for my 1100D with it's default 55mm lens attached (and fully extended)? It has been suggested that I could make the dew shield in a funnel shape (kind of like those things dogs sometimes have to wear), which could be an option, but obviously I would prefer to make a straight tube if I can, because it would be a lot easier. I suppose if I went for the tube option then I could just make it long, and then cut it down a bit more each time until it doesn't cause a problem.

I think the rule of thumb is to extend the dew shield by 2 x aperture, adding a bit to fix to the end of the scope / lens.

I made mine to be 3 x aperture and all is ok

[ianpwilliams]

So I'm thinking maybe a cone that attaches to the end of the lens, roughly the same length as the lens, and widening to 3x the aperture. But then the tricky part is attaching it to the lens. Any recommendations for that? A straightforward tube would have been so much easier because it would have held itself in place unlike a cone, but then it couldn't be very long.

[peroni]

So I'm thinking maybe a cone that attaches to the end of the lens, roughly the same length as the lens, and widening to 3x the aperture. But then the tricky part is attaching it to the lens. Any recommendations for that? A straightforward tube would have been so much easier because it would have held itself in place unlike a cone, but then it couldn't be very long.

I use a straight forward tube with my lens, scope, and finder guider. This will allow you to adjust the length of the dew shield by sliding up and down the scope/lens should you start to see vignetting.

Obviously for a scope as it is fixed focal length it's easier to determine the length of dew shield.

For the lens, a bit more trial and error. If you open the lens to a short focal length then a shorter dew shield is required. Not sure if the benefits of shield would be lost at say 18mm FL

My vote says try the tube first. If it doesn't work. Go down the more complicated cone route.

[m.tweedy]

download the relevant lens size. Print on card and you have one. you could of course laminate it and you have a semi permanent dew resistant solution

 http://www.lenshoods.net/canon.php

[ianpwilliams]

Interesting, thanks for that. Might try making a cone based on one of those lens hoods, and maybe a tube as well.

[ianpwilliams]

The diameter needs to be quite large to avoid vignetting i use this on my kit lens and the 50mm lens.

Alan

Can I ask what this is? It kind of looks like a home-made one, but I can't tell.

And would something like this do the trick I wonder?

http://www.ebay.co.uk/itm/58mm-Collapsible-Rubber-Lens-Hood-For-Canon-Nikon-Sony-Camera-Photography-/281130508615?pt=UK_Photography_CameraLenses_Lens_caps_hoods_adaptors_ET&hash=item4174af2147

I'm trying to work out dimensions for a home-made dew shield cone, and it's already frying my brain.

[Alien 13]

Can I ask what this is? It kind of looks like a home-made one, but I can't tell.

And would something like this do the trick I wonder?

http://www.ebay.co.uk/itm/58mm-Collapsible-Rubber-Lens-Hood-For-Canon-Nikon-Sony-Camera-Photography-/281130508615?pt=UK_Photography_CameraLenses_Lens_caps_hoods_adaptors_ET&hash=item4174af2147

I'm trying to work out dimensions for a home-made dew shield cone, and it's already frying my brain.

That is similar to what i bought mine was a 72mm version with a 58-72mm step up ring but the one shown looks ideal and rubber helps with insulation.

Alan

[ianpwilliams]

Ok good, that's bought. And I can always attach my own extra bit to it if I want to.

[ianpwilliams]

The lens hood has arrived, and it screws onto the Hoya UV lens filter fine. However, it does only add just under 2" of length to the end of the camera lens (see attached), whereas your one seems to have an extra bit. Do you think this would be enough to act as a dew shield, or should I be looking to maybe extend the lens hood by attaching more material to it?

[JOC]

These dew shields seem quite important.  Not wanting to get my brand new telescope damper than it will get anyway I've already got my camping mat on order and the 'scope is not even delivered yet!!  LOL  I thought I might experiment with sticky Velcro for joining it together in areas where I might one day want to remove it and double sided tape in other areas.

[D Wright]

I made a dew shield for my 10" reflector from a yoga mat from Sports Direct. It is fabric coated neoprene foam with a stiched edge. I used sticky velcro to join it where it wraps around the tube but I found that the adhesive was lifting so I stapled the velcro to the mat. Now I have a very nice dew shield which works a treat. As a finishing touch I stencilled "Orion" on it in white. Looks the biz.

[Ceramus]

The sports direct gym mat is excellent, it also serves as a light shroud for my 300 p Flextube.

[Kimboman]

I used a soft plastic plant pot for growing tomatoes in it works well and is truLey round , it looks  good with a small outward taper and it does not mark the tube

[SaskGrass]

I have a Celestron 925 HD. made a dew shield out of a 5 gallon pail.

https://youtu.be/8Oj8n78haHE

[Philip.]

I have one of these lying around, would that be any good for a dew shield ? https://www.argos.co.uk/product/3405712