Whats the difference?

[Jambo_UK]

Can someone tell me the difference between long and short pars, What are each used for?

 

Thanks for all the help everyone,

 

from

 

Jambo

[dominicgross]

well apart from one being short and one being longer (boom boom) I find that the short nose are better for flooding, while long nose's are slighly more directional.

 

I tend to use short noses as floor cans for moody rock lighting, with long noses rigged as cheep and chearfull washes.

[Stu]

Well basically (and this isn't a very scientific explanation here) but the longer the lens tube (or in this case, the cylinder bit of metal after the lamp!) the narrower the beam will be in terms of degrees when it hits the stage.

 

A good example of this is to look at this link at the Strand Archive for the Cantata Range.

 

As you can see, the 11/26 (narrow) has a long lens tube, the 18/32 (medium) has a medium lens tube and the 26/44 (wide) has a short lens tube.

 

Anyone up for the science behind it all?

 

Stu

[P. Funk]

umm.. in the case of a par can, any light that is emitted at a wider angle than that of between the source and the end of the can, is cut off (turned into heat) by the metal cylinder...

 

I can't do the rest of the optics now.. too tired. basically with 2 lenses u need a longer focal length to get the angle out the end u want...

[Bryson]

Does anyone know at which lamp lens angle the difference between long and short cans matters? I'm guessing a CP60 won't get any wider anyway, but would it make a difference to a 61 or a 62?

[themadhippy]

And short nose cans tend to burn out dark gels quicker than normal ones,or at least the ones ive used did

[Stu]

Does anyone know at which lamp lens angle the difference between long and short cans matters? ...would it make a difference to a 62?

From what I can remember it makes a difference to CP62s, but not used short nosed on 61s so couldn't comment.

 

Stu

[Tomo]

Does anyone know at which lamp lens angle the difference between long and short cans matters?

I think it's only really the extra wide ones (EXG or something)

There's a little bit of extra spill for a CP62 in a short nosed, but I can't really think why anyone would want to put a parcan somewhere with a throw long enough to care.

 

The problem with short nosed cans is that the gel is much closer to the lamp, so it burns out a lot faster. The main advantage is that they're smaller, which makes them much better floor cans in my opinion - smaller they are, the less likely the are to get kicked by careless cast or crew.

[robloxley]

Well basically (and this isn't a very scientific explanation here) but the longer the lens tube (or in this case, the cylinder bit of metal after the lamp!) the narrower the beam will be in terms of degrees when it hits the stage.

 

A good example of this is to look at this link at the Strand Archive for the Cantata Range.

I think you're confusing profiles where the lenses are in the lenstube, and parcans where the lens is in the front of the lamp. The effect of a long-nosed parcan is similar to putting a top-hat onto a short-nosed one, reducing spill. Also as mentioned there's the gel issue.

 

I tend to find the issue is more apparent when using birdies (Par16), where shortnosed ones are relatively rare and 60 degree lamps often required.

[smeggie]

Hi

AFAIK, the gfels burn out quicker on shorties purely due to their being closer to the lamp. = more heat absorbed/area than on long nosed pars.

 

 

-BIRDIES! the best desk lamps around - and they're free!

sorry, caught in the memory.

 

cheers

smeggie

[Stu]

I think you're confusing profiles where the lenses are in the lenstube, and parcans where the lens is in the front of the lamp. <snip etc>

Yes admitteledly it was a bad way of explaining it, wasn't feeling very well yesterday so I think I can consign that one to the silly amount of codine I was taking for the pain :** laughs out loud **:

 

Stu