[lovemehate]

I have a 18-55mm and a SMCP-A 50mm f/2.0 Lens . do I need a hood for a 50mm?

so far I have found Fotodiox Lens Hood for Pentax Ph-Rba SMC DA 18-55mm f/3.5-5.6 AL II Zoom Lens as 38741

That should fit the 18-55mm so what about the A 50mm?

[pschlute]

The hood for the 18-55 is a bayonet mount. It wont fit on the A 50mm. For that you need a screw mount hood with a 49mm thread or one of the old plastic Pentax hoods with a pinch mount.

[Impartial]

Note that there are many, many rubber hoods available which will fit around a 49mm filter thread and stay out of the way of the lens cap. I use a collapsible one, myself.

[SpecialK]

Every lens should have a hood that is designed for its focal length. A hood for a zoom is designed for the wide end, so it is not so good for a longer prime in that zoom range.

[Lowell Goudge]

Aside from fit issues the most effective lens hoods are specifically designed for one focal length only, since the field of vioew is different for each focal length, the lens hood is also different. Hoods for zooms are only optimum at the widest focal length as they would outerwise cause vignetting if made any longer to work at longer focal lengths. as a result yes you do need a separate hood

I use exclusively screw on metal hoods, or clip on plastic hoods for my older lenses that do not come supplied with bayonet hoods.

I look in the used section at Henry's in Mississauga (Toronto) where they have all the clearance goods and can generally get hoods for $4 each.

There are lots of posts that show the benefit of a hood on various lenses not jist in reducing visible flare but also in improving contrast.

Note that the collapsable rubber hoods generally have a very wide opening and do not give maximum protection for the focal length.

[RioRico]

I must disagree a bit with Lowell. Inflexible lens hoods of solid metal or plastic are indeed designed for specific lenses and focal lengths, but they're not the only options. Whaat is most important is that the hood never vignette the image -- no corner darkening.

Beyond that, you want the hood to prevent incident light from hitting the lens. Why? Such light causes flaring and reduces contrast. You'll notice this especially if you frame an image so that the sun or other bright light shines directly into the lens. If I use my 100mm Meyer lens, I can choose between a hood that is 16mm deep, and another that is 48mm deep. The deeper shade lets me shoot closer to the sun -- but the 16mm hood makes the lens rather small in my carry bag.

When a solid hood is supplied with a lens, I generally use it, especially if it reverse-mounts on the lens when not in use. Otherwise, I use a fold-back rubber hood. Every lens that goes into my bag has a hood on it, unless it has a deep front inset. If those were all non-reversed solid hoods, my bag wouldn't hold as many lenses. Also, I do a fair amount of street shooting. A lens with a big solid hood can seem more intimidating than with a rubber hood, folded back when not shooting directly into lights.

A major feature of hoods is protection, keeping your glass from being scratched by drops or brush-bys. A rubber hood does offer protection -- true, not as much as a longer solid hood, but still considerably better than nothing. I've used such hoods for decades on film and digital cams, and I haven't lost a lens yet. Your mileage may vary.

[Lowell Goudge]

I must disagree a bit with Lowell. Inflexible lens hoods of solid metal or plastic are indeed designed for specific lenses and focal lengths, but they're not the only options. Whaat is most important is that the hood never vignette the image -- no corner darkening.

Beyond that, you want the hood to prevent incident light from hitting the lens. Why? Such light causes flaring and reduces contrast. You'll notice this especially if you frame an image so that the sun or other bright light shines directly into the lens. If I use my 100mm Meyer lens, I can choose between a hood that is 16mm deep, and another that is 48mm deep. The deeper shade lets me shoot closer to the sun -- but the 16mm hood makes the lens rather small in my carry bag.

When a solid hood is supplied with a lens, I generally use it, especially if it reverse-mounts on the lens when not in use. Otherwise, I use a fold-back rubber hood. Every lens that goes into my bag has a hood on it, unless it has a deep front inset. If those were all non-reversed solid hoods, my bag wouldn't hold as many lenses. Also, I do a fair amount of street shooting. A lens with a big solid hood can seem more intimidating than with a rubber hood, folded back when not shooting directly into lights.

A major feature of hoods is protection, keeping your glass from being scratched by drops or brush-bys. A rubber hood does offer protection -- true, not as much as a longer solid hood, but still considerably better than nothing. I've used such hoods for decades on film and digital cams, and I haven't lost a lens yet. Your mileage may vary.

I agree vignetting is a potential issue, and also if you are concerned about space a shorter hood may be preferred, but generally my hoods can be inverted an dput back over the lens so it is not a killer form me.

the reason I like metal hoods is that they generally can offer narrower field of view suitable for a 50mm lens on a DSLR. rubber fold back hoods, unless especially designed for telephoto typically have such a wide angle that they offer little additional protection. I have poted to go for the maximum. As an additional point, most "stock hoods" for older lenses are not optimum because they are designed for the field of view based upon full frame not ASP-C sensors.

A long time ago, i posted a spreadsheet to calculate the hood diameter and length for any lens, based upon sensor size. it was called hoodcalc.exe It is hard to find these days on the web (I didn't create it) but I have modified it to calculate not just circular hoods but also tulip ones, as well as account for the inset of the lens at the front of the lens and the true diameter of the front element.

It works very well

[lovemehate]

this Is why I dislike having to order everything online

So I guess I need something like Mennon DC-s 49 Screw Mount 49mm Flower Lens Hood, Black ?

should i spend more and get metal vs plastic/rubber?

[pschlute]

this Is why I dislike having to order everything online

So I guess I need something like Mennon DC-s 49 Screw Mount 49mm Flower Lens Hood, Black ?

should i spend more and get metal vs plastic/rubber?

That hood will certainly fit the 50mm lens, but in my view is not the best. As was advised earlier... zoom lens hoods (which your link looks like) are a compromise as they must not vignette at the wide angle, and so dont provide the best protection at the other end of the focal length.

This is what I use on 50mm focal length lenses BW Metal Lens Hood 950 - Lens Hoods Caps

Just make sure you order it with a 49mm thread.

[SOldBear]

Here's the hood for my FA50. It protects the lens very well, and takes up virtually no space:



This kind of "hood" does not work with zoom lenses (vignetting), however.

[lovemehate]

wait am confused...Its a 50mm lens but I need a 49mm lens hod? how can you tell? will this work for my Pentax SMCP-A 50mm f/2.0 Lens

Zykkor 49mm Universal Telematic Wide/Zoom 3 Position Rubber Lens Hood

[Ira]

wait am confused...Its a 50mm lens but I need a 49mm lens hod? how can you tell? will this work for my Pentax SMCP-A 50mm f/2.0 Lens

Zykkor 49mm Universal Telematic Wide/Zoom 3 Position Rubber Lens Hood

The focal length of the lens--50mm, for example--has nothing to do with the DIAMETER of the lens where you have the threaded section to screw in a hood or filter.

A 35mm lens can have a filter diameter of 58mm, because the physical width of that section of the lens is so wide.

To summarize, the numbers have nothing to do with each other, and when you buy a lens, the filter diameter will always be specified in the literature, and usually (but not always!!!) on the lens itself. And you can find 50ish mm lens that require either 49mm, 50mm, 52mm, etc. size hoods/filters,

[lovemehate]

so how do i know when am looking online, like that I was talking about, will the hood always say what lens its ment for? Mines 50mm so if the lens hood says 50mm itll work? so what about thread size then?

[RioRico]

so how do i know when am looking online, like that I was talking about, will the hood always say what lens its ment for? Mines 50mm so if the lens hood says 50mm itll work? so what about thread size then?

Again, the focal length and the thread diameter have nothing to do with each other. Common thread diameters are 49-52-55-58-62-67-72mm. (55-58mm lenses are common; 49-52-62-67-72mm lenses are rare or non-existent.)

A listing for a lens hood should ALWAYS give its thread diameter. A listing may or may not indicate what focal lengths or lens it's meant for, especially with used hoods on eBay. I recently bought a few rubber hoods (CHEAP!) with 55mm threads. Some were obviously for 'normal' lenses; some were very short, only for very wide lenses. At two bucks each, I won't complain.

Some name-brand hoods may say just what lenses they're intended for. I have an Asahi Pentax metal hood, 52mm deep with 49mm thread, that's labeled "TAKUMAR 1:3.5 135mm - 1:4 150mm" (meant for full-frame cameras) but it is quite usable on any 49mm-thread lens with a focal length of about 40mm or longer, ON AN APS-C CAMERA. I just tested it on my F35-70 and it vignettes slightly below 40mm on my K20D. But on my full-frame ZX-M film camera, that hood vignettes below 50mm.

And the above shows that there are no fixed standards. Any specific hood may or may not vignette on any specific lens, depending on what camera it's on. I fortunately own too many lenses, so if I get a hood that doesn't work where I intended it, I can always use it somewhere else.

[lovemehate]

I understand what your saying, I guess Its just not making it clear when looking lens hoods online what to buy, as I need to do this soon so that i can get them not too long after my cam arrives.

how about Fotodiox Lens Hood for Pentax Ph-Rba SMC DA 18-55mm f/3.5-5.6 AL II Zoom Lens as 38741 on my 18-55mm f/3.5-5.6 AL

and Zykkor 49mm Universal Telematic Wide/Zoom 3 Position Rubber Lens Hood on my Pentax SMCP-A 50mm f/2.0 Lens?