Modern filters and old lenses.

[srichards]

I got myself a bayonet 1 to 49mm thread adapter so I can stick on a UV filter on the Automat as old lenses generally aren't coated.

Is this likely to make any difference at all? Also would there be much improvement between using an old Jessops UV filter and a brand new Hoya multi coated professional one?

I was also wondering about using a polariser but obviously with a TLR it's more of a challenge....

 

[donut]

i think it would have to be quite old to not have any coating at all ,,,,

 

[srichards]

It's 1938 ish so I'd imagine it wouldn't have any or they would have worn away?

 

[steveo_mcg]

Doesn't the coating cut down on reflections between the lens elements? If so putting a filter on the front won't help, I understand film is already sufficiently insensitive to UV to not worry about a UV filter. You'd be better buying a yellow or orange filter and just leaving it in place, if shooting b&w.

 

[skysh4rk]

I would just use a hood and watch out for the sun shining directly into the taking lens. The bonus of the hood is that it makes TLRs look even more charming.

I've never bothered with filters on TLRs.

 

[srichards]

Doesn't the coating cut down on reflections between the lens elements? If so putting a filter on the front won't help, I understand film is already sufficiently insensitive to UV to not worry about a UV filter. You'd be better buying a yellow or orange filter and just leaving it in place, if shooting b&w.

Not a scooby about internal reflections. Didn't consider those!

I don't have a lens cap of any kind for it so it will sort of serve as some protection for it too.

I thought about hoods. Might get one of those as well.

 

[StephenM]

The idea for coating goes back to before photography, but didn't really become successful until vacuum deposition was perfected in 1935. Which says nothing about your lens.

Flare occurs at glass to air surfaces, and is reduced by coating. Reduced, but not eliminated, so adding any filter will potentially degrade optical performance. It won't compensate for uncoated lenses.

Uncoated, you'll lose about 5% of the light at each air/glass surface (which is why modern upteen dozen element lenses were only practical after improved coatings became available). Single coating reduces the loss to about 3% and multicoating to about 1%. If photographing using monochromatic light single coating can actually be better. In normal use, go multi.

Polarisers used to have a small dot on the rotating mount so that you could adjust by eye and transfer the same orientation to the lens when fitted. Most of my equipment is so old, that modern filters might have dispensed with this as unecssary (like depth of field scales on lenses).

Lens coatings are norammly metallic oxides. Details on request

 

[StephenM]

There was a very interesting article in a 1960s British Journal of Photography Almanac (a year book) on sources of internal reflections. A surprising amount (at that time) occurred within the camera and was unconnected with the lens. (Sorry, Steve's post wasn't there when I started my reply.)

 

[FruitFlakes]

I use a B+W filter on my 50mm Summicron rigid. Makes little difference to the image quality/flare resistance, but I know that the coatings on my version of that lens can be quite soft so I'd rather clean the filter than the front element itself.

 

[StephenM]

I thought about hoods. Might get one of those as well.

If you want to reduce flare, this is essential. An efficient hood should prevent as much non0-image forming light getting to the lens. You don't usually take circular photos (Impossible project new film and old Kodaks notwithstanding) so a hood that cuts the angle of view to that of the lens helps. Angle of view can change slightly as you focus, so a bellows hood is the most effective, but not practical on a TLR!

 

[srichards]

If you want to reduce flare, this is essential. An efficient hood should prevent as much non0-image forming light getting to the lens. You don't usually take circular photos (Impossible project new film and old Kodaks notwithstanding) so a hood that cuts the angle of view to that of the lens helps. Angle of view can change slightly as you focus, so a bellows hood is the most effective, but not practical on a TLR!

I was looking at one of those cheapy rubbery ones as you can at least choose how far you have them sticking out which you can't with the plastic ones.

 

[skysh4rk]

I was looking at one of those cheapy rubbery ones as you can at least choose how far you have them sticking out which you can't with the plastic ones.

I'd be looking for a hood originally intended for a TLR, whether it's manufactured by Rollei, Minolta, Yashica, etc. They're square, so better match the angle of view, and you know that they won't block the viewing lens.

 

[ChrisR]

Interesting. The one on my Autocord fits diagonally rather than like that!

 

[skysh4rk]

Interesting. The one on my Autocord fits diagonally rather than like that!

Are you sure that you're putting it on correctly? The fitting will usually allow those hoods to be put on diagonally, but they should be positioned how it is in the photo.

 

[ChrisR]

Are you sure that you're putting it on correctly? The fitting will usually allow those hoods to be put on diagonally, but they should be positioned how it is in the photo.

Diagonal is how it came, and seemed to be how it went back on when I took it off... but, now you mention it, there IS another way! Looks much better now, thanks.

 

[Strapps]

I bought a plastic bay-1 hood for my Yash 124 from ebay, all of a fiver including delivery and it does the job.

 

[ChrisR]

Diagonal is how it came, and seemed to be how it went back on when I took it off... but, now you mention it, there IS another way! Looks much better now, thanks.

Oh dear, it appears the first part of this was me talking b*ll*cks. Found the pic of the Autocord I took for the new toys thread, and the hood was definitely square on.