Enlarger lens hood

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ChrisR
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Enlarger lens hood

Post by ChrisR »

Why would anyone want a hood on an enlarger lens?

Image

The only light source in my darkroom was a luminous sundial.

rjlittlefield
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Post by rjlittlefield »

Maybe made for people who wanted to use it as a taking lens?

Never have seen one, though.

--Rik

ray_parkhurst
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Post by ray_parkhurst »

I have seen a couple with hoods. Wouldn't a hood do the same thing for enlarging as it does for taking, except in reverse? ie it would control the light that might exit the lens from unwanted angles so that it does not hit objects in the room and re-reflect to the film, reducing print contrast. But I'd be afraid to use a hood as shown since reflections off the inner surfaces might do more damage than the hood avoids. Just speculating.

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Post by rjlittlefield »

ray_parkhurst wrote:Wouldn't a hood do the same thing for enlarging as it does for taking, except in reverse?
No, it's a very different situation. When taking, light comes from all around the great unwashed world, potentially hits the lens from all sorts of angles, and your challenge is to keep any that originates outside the intended frame away from the sensor. But with an enlarger, the film holder also serves as a mask, so almost all light that gets to the enlarger lens has already been restricted to the intended frame. (The exception is what little might come from stray reflections off the walls of the chamber between film and lens, especially if the light source is highly diffuse.) Then the aperture of the enlarger lens further restricts the light that gets through the lens, so that in the end, hardly any light comes out at odd angles except what bounces off dust on the lens surface.

You don't need a hood with an enlarger any more than you need one on a slide projector.

On the other hand, you might like to have one if you're spooked by seeing those bright dust spots on the lens surface. I imagine the manufacturers would have been be happy to sell whatever people would buy.

--Rik

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Re: Enlarger lens hood

Post by jjphoto »

ChrisR wrote:Why would anyone want a hood on an enlarger lens?

Image

The only light source in my darkroom was a luminous sundial.
Where did that hood(?) come from and is it actually a lens hood for that lens or does it just happen to fit it?

I've never seen a lens with such thick walls.

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Post by ChrisR »

It came with the lens, which is of course quite old (80's). It was on a flange with "35" marked on it which looks like one which would go on an enlarger, but could I guess have been some sort of camera.
I'll snap the flange later.

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Post by jjphoto »

ChrisR wrote:It came with the lens, which is of course quite old (80's). It was on a flange with "35" marked on it which looks like one which would go on an enlarger, but could I guess have been some sort of camera.
I'll snap the flange later.
Unless you find some document that states that this 'hood' is specifically intended for this lens then I would suggest it's just a coincidence or just an odd item that happens to fit the lens. After all filter threads are very common sizes so this 'hood', or whatever it is, may be intended for an altogether different lens or application. It's too thick for a lens hood and it looks more like some kind of adapter, maybe for astronomy.

Not that I have anything against lens hoods for enlarging lenses, I highly recommend them and use them whenever possible. I avoid buying lenses with damaged filter threads for the very reason that they prevent the use of a hood.

Image

I've also gone to some length to list filter sizes for enlarging lenses whenever possible ( http://photocornucopia.com/1061.html ) as I do see lens hoods as being very valuable items for use with enlarging lenses when used as taking lenses.

Alan Wood
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Post by Alan Wood »

When I had a darkroom, I always used a hood on my enlarger lenses.

The front elements were not recessed, and I did not want to touch the glass while reaching up to change the aperture.

The hoods did not come with the lenses, I bought ones intended for camera lenses.

Alan Wood

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Post by ChrisR »

I think you may be right, Alan. The flange reminds me of machine printers, where shorter lenses were used for "126" film, though of course that may not be its original application. With a recessed mount it's easier to "find". A normal camera hood wouldn't be ideal, being flared - they would be in the way of the aperture ring.

I'd say it was made as a hood not an adapter; there are no other marks or threads, and it's finely grooved on the inside.
Of course hoods are useful for taking lenses. This FL would be an unusual choice for one, but possibly there's a microfiche application.

jj - nice lens info. There's a longer list of enlarger lens filter threads including this one, in our FAQ section. (It's 30.5mm)

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Post by ray_parkhurst »

I took a closer look at the "hoods" I have that mount to enlarger lenses, and I think they are actually either for reversing or adding larger filters.

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Lens hood

Post by Olympusman »

I think Ray nailed it. The hood would make it easier to mount polycontrast filter holders such as the Kodak holders which used three centering screws.
Otherwise, you would have to mount the filter holder on the aperture ring, which is not very convenient at all.
Mike
Michael Reese Much FRMS EMS Bethlehem, Pennsylvania, USA

ChrisR
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Post by ChrisR »

Makes sense - it would explain why it's made quite strongly.

https://www.uniquephoto.com/below-lens- ... rd-1762617

As first post by tkamiya here:
http://www.apug.org/forums/archive/inde ... 71154.html

A short FL lens like this one in a recessed mount, wouldn't permit either fixing, without the "extension" which looks like a hood.

Olympusman
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Enlarger lens hood

Post by Olympusman »

Ray and I described that the use of a lens hood would be to accept filter holders. This is what the filter holder from the Kodak Polycontrast Filter Set looks like:

Image

Mike
Michael Reese Much FRMS EMS Bethlehem, Pennsylvania, USA

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