There is an area on the side of the chicken coop/garage that is empty. It is pitch black at night, and it is where the door to get into the chicken coop is. Since I have to check on the chickens at night sometimes, I feel uncomfortable going through that really dark part. Because of this, I decided to install a 70w HPS yardblaster on the wall. Since it is a cement wall, I had to make a special mount for it. The yardblaster is about 6 feet above the ground. It is also close to the neighbor's driveway, but a large lilac bush blocks the light from getting into the driveway. Well, night fell, the light came on and I immediately noticed that it was much brighter than I expected. It was shining onto other houses and lighting a much larger area than I would have wanted. My mom told me to shut it off until I can make it less bright so it does not disturb the neighbors. So I shut it off, and now I have to make it so it is not as bright. The once pitch black area was lit very well, but there was way too much light trespass. I was wondering if maybe lowering the wattage to 50w HPS would maybe help. Is 50w HPS much dimmer than 70w? I really don't want to do 35w since those lamps bother me for some reason, but I might have to. Would any of these help? I still want the area lit well, but not the neighboring houses.

How do 35w HPS bother you?

How do 35w HPS bother you?

Not exactly sure. Maybe since they are only available in medium base. If I have to, I might just use that but I would prefer something a bit higher than that since the area needs to be well lit.

To change wattage this also means to change the ballast as well.  I would recomend full cut off fixture
Or Par 38  MH fixture that way you can direct the light
Where it needed.

If the light distribution is bad, rethink your choice of lantern and placement before you go to lamp wattage

I never seen 35W in wide use, so maybe the problem is limited availability ? You can put it up, if one day it EOLs and you stuck without a replacement lamp, then you can convert it (at least temporarily, untill you find another solution) back to 70W. As a quick fix, the E26/27 to PL adapters can work just fine on the output of HID chokes (choke, not HX/CWA, and if the ignitor is disabled), so disconnect a wire from the ignitor, screw in the PL and you get it going again for now

If the light distribution is bad, rethink your choice of lantern and placement before you go to lamp wattage

I never seen 35W in wide use, so maybe the problem is limited availability ? You can put it up, if one day it EOLs and you stuck without a replacement lamp, then you can convert it (at least temporarily, untill you find another solution) back to 70W. As a quick fix, the E26/27 to PL adapters can work just fine on the output of HID chokes (choke, not HX/CWA, and if the ignitor is disabled), so disconnect a wire from the ignitor, screw in the PL and you get it going again for now

35w HPS lamps are very common around here for residential use, but you never see them in floodlights or cobraheads. Also, the light's optics focus the light down to where I want it, but there is a little bit of light shining on the other houses. It's not very bright making me think that lowering the wattage should help with the problem.

To change wattage this also means to change the ballast as well.  I would recomend full cut off fixture
Or Par 38  MH fixture that way you can direct the light
Where it needed.

I ordered a 35w PSMH landscape lighting ballast on eBay a few days ago. Once it comes I might be able to set up a floodlight with a 35w PAR30 lamp. Can MH par lamps be exposed to weather like incandescents?

Then whats the problem with 35W ?

What glass is the PAR made of ? If same as the normal Incandescent, then i dont see potential problem with the lamp. But what about the socket ? Are you going to supply ignitor voltage to a PAR socket intended for 120V only ?

Then whats the problem with 35W ?

What glass is the PAR made of ? If same as the normal Incandescent, then i dont see potential problem with the lamp. But what about the socket ? Are you going to supply ignitor voltage to a PAR socket intended for 120V only ?

35w HPS lamps seem awfully dim and would probably not light the area very well. But then again my 35w HPS lamps are very spent and maybe they have lost most of their lumens.

If I were to use a par30 lamp I would replace the socket with a pulse rated socket.

And would your pulse rated setup have the same water protection (gasket around PAR lampneck, ..) as the normal one ? That is, you replace the inner socket inside the PAR luminaire ?

Really, a yardblaster or wallpack are at the extreme bottom of the list of things to use if annoying the neighbors is a consideration. Use a full cuttoff cobrahead street light or something.

Just put a piece of cardboard or any solid material inside the refractor to block the light. Lowering the wattage won't help much.

At some point it will. But dont forget, that if the light is installed on a wall, then it lights very brightly a spot on the wall, and that spot acts as reflector

At some point it will. But dont forget, that if the light is installed on a wall, then it lights very brightly a spot on the wall, and that spot acts as reflector

Well, if the ground is grass, then the low green levels from the HPS will not cause as much light than if the ground was a mirror, for example.
It would be even better if the ground was gray gravel, so it would not reflect much light.
Another way to find a good light level is to go to the neighbor's house with a lux meter, and divide that by 2 with a 35W HPS, and show the neighbors an equivalent brightness, and ask them if that is ok.
That's a very scientific way of doing it.
What color is the neighbor's house? If you switch to a MH it might be worse, because of the spectrum. Red? Switch to MV. Blue? Use HPS. Green? I don't know, Hg free HPS? LPS? LPS is actually more pleasant than you think.

The glare coming to the neighbors depends on the color of your wall not theirs

Or relocate the light so that it and the wall below it is not in plain sight to the neighbors windows/garden