Prisms on flagsticks?

[cristphoto]

What is the purpose for adding prisms on flagsticks? I get that the idea is to make lasering easier but I've always just aimed at the flag itself (a much larger target). Plus I can't see prisms from the fairway even if I wanted to use them. Or am I missing something (like the laser's field of view is wide enough to pick up the flag and prism). Can anyone clarify? Thanks. 

[ThinkingPlus]

Actually they are corner cube retros. The LRF beam by the time it reaches the flag is several meters in diameter (would be a little smaller if you are close) so it easily overfills the flag.

 

If you just have a flag plus stick, the beam scatters back in all directions. You only get a small amount back to the sensor in the LRF and your aim needs to be pretty good to get a good reading. Your range will suffer as well.

 

Retros, on the other hand, reflect light directly back to the source. So whatever bit of the laser beam which hits the retro all goes back to the LRF sensor.  Lots of signal and greater range. You don't have to aim as well because so much light comes back even a poorly aimed beam results in plenty of signal.

[smoova]

1 hour ago, ThinkingPlus said:

Actually they are corner cube retros. The LRF beam by the time it reaches the flag is several meters in diameter (would be a little smaller if you are close) so it easily overfills the flag.

 

If you just have a flag plus stick, the beam scatters back in all directions. You only get a small amount back to the sensor in the LRF and your aim needs to be pretty good to get a good reading. Your range will suffer as well.

 

Retros, on the other hand, reflect light directly back to the source. So whatever bit of the laser beam which hits the retro all goes back to the LRF sensor.  Lots of signal and greater range. You don't have to aim as well because so much light comes back even a poorly aimed beam results in plenty of signal.

Username checks out.

[North Butte]

My home course changed out flagsticks a year or so ago and the new ones don't have reflectors. Man, I miss the reflectors. 

[cristphoto]

23 hours ago, North Butte said:

My home course changed out flagsticks a year or so ago and the new ones don't have reflectors. Man, I miss the reflectors. 

 

So did they decide the reflectors weren't effective? 

[boyscout]

We brought some reflector tape and put it on every flag stick. Cost maybe $30, we were fed up.

[phil75070]

I'm not sure that I've played a course with reflectors. If so, I didn't notice them and still "shot" either the flagstick itself or the flag on top of it. I've had no issues doing that.

[TM_HOYER]

I think the prisms go back to the early rangefinder when Laser Link rangefinders were one of the few rangefinders available. They required the prisms to lock in yardages. 

[North Butte]

3 hours ago, cristphoto said:

 

So did they decide the reflectors weren't effective? 

I haven't asked but I think when they replaced the (very old and beat up) flagsticks a while back, they just didn't buy ones with reflectors. Maybe they thought prisms weren't needed any more since their current carts have GPS screens built in. But the majority of guys I play with walk and almost all of us use lasers.

[ThinkingPlus]

19 minutes ago, North Butte said:

I haven't asked but I think when they replaced the (very old and beat up) flagsticks a while back, they just didn't buy ones with reflectors. Maybe they thought prisms weren't needed any more since their current carts have GPS screens built in. But the majority of guys I play with walk and almost all of us use lasers.

I have seen retros that can be added to the flagsticks if they aren't built-in. Kind of a rubber part that houses the retro and slips over the flagstick making a tight fit. You can also add ScotchBrite reflective tape (not as effective). Lots of different kinds.  Not sure which would be best.  Haven't had a need to look at that stuff since I retired.

[North Butte]

Many years ago (15?) they had plain flagsticks, no reflectors. About that time they added some screw-on ones (or something like that) to the very top of the sticks.

 

Then about 10 years ago they replaced the old sticks with new ones having the prisms built in.

 

Last year they replace the ones with prisms with very nice news ones, alas without prisms. I hope one day they put add-on reflectors on there but who knows. 

[grochol17]

On 7/30/2023 at 2:19 PM, cristphoto said:

 

So did they decide the reflectors weren't effective? 

 

I'm sure it was an issue of cost... I just checked one company online and it looks like they are charging an extra $50 for flag sticks with reflectors built in.  Another is charging $50 for a reflector that attaches to the top of the stick. 

 

For what it is worth, the retroreflector technology works just fine... NASA astronauts put them on the Moon during the Apollo missions and scientists have been using them ever since to measure the Moon's orbit and keep track of any tiny changes.  But, maybe more along the lines of what you were asking, it is possible that with newer lasers rangefinders  the signal return strength off of the flag alone is enough to get accurate enough distances that the retroreflectors aren't worth the cost.  When playing I always laser the flag a few times just to make sure I'm actually getting a number to the flag and not the things behind it.  I played two courses recently, one with retroreflectors and one without.  My old Tour V2 locked on faster to the flags with the retroreflectors and always gave me the same number, whereas the flags without would vary by a yard or two, or I'd sometimes get the trees in background.  Obviously I'm not good enough that 150 vs 152 really matters to me, so they probably aren't necessary in most cases, but the retroreflectors do help in getting yardages faster, especially if there's a lot of stuff behind the greens.