Both are line voltage. The low voltage fixtures are stepped down by use of a transformer built into the fixture. Most of the low voltage cans are 4" and the halogen lamps will tend to give a more focused light. 6" cans with IC flods will give you a more diffussed light, more ambient if you would. By the way, both types/sizes are dimmable.

If you are considering a track or cable system I much prefer the track as I think the cable systems look rather crude. We have installed track systems in commercial settings but rarly in residential. The "we" I use, my son and I are master electricians in Dallas.

"What are the pros and cons of low voltage and line voltage halogen lights?"

Other than the numerous references on these boards to the heat produced and the spoiled food stored on the bottom shelve of upper cabinets.
If your choice of halogen is because of the "white light",
and you missed the numerous references on these boards to that same quality of light produced by both fluorescent and LED, both of which are dimmable, cheaper to operate, cool operating and with a lamp life expectancy which is exponentially longer.
Another benefit is that if you reside in CA.and are intending to permit your project, both meet CA title 24,
halogen do not.

"there was no advantage to low voltage"

Other than when the individual fixtures are are transformer reduced, the individual failure leaves the others operational.
As for the power consumption, a watt is a watt.

"Is there a standard recommendation for spacing recessed halogens in a kitchen ceiling"

Which will depend upon the size of the fixture and the lamp you select. Spot and flood have different illumination cones which are displayed in a PDF format at most fixture web sites.

"why would you choose cable halogens vs. recessed, or vice versa?"

And for all of the reason previously annotated, I fervently voice my objections.

snoonyb, you've given me a little information, tho not all clearly enough to understand, so thank you. But you seem to have a chip on your shoulder about asking questions that have already been referenced on these boards "numerous times." For reasons I don't need to go into here, I confess, I haven't read every post on this forum about lighting. If you don't like posts about topics already discussed, please ignore it rather than indirectly admonish the poster. People come here for help -- all of our lives aren't so easy that we're perfect forum users.

"all of our lives aren't so easy that we're perfect forum users."

I'll be 68 in 24 days.
I work in the trades seven days a week, 12hrs a day, and not in supervision.
So when I encounter a situation that warrants "Internet dentistry" to ferret out the specific information requested,
I respond with the LACK of specificity, as an exercise in reseprocity, as the question warrants.

"For reasons I don't need to go into here, I confess, I haven't read every post on this forum about lighting."

"Posted by egganddart49 (My Page) on Fri, Sep 19, 08 at 17:40
Well snoonyb, I did look all over and haven't found it."

And its not just the lighting, its the kitchen and the wiring.
There is also a search engine for this site.

"tho not all clearly enough to understand,"

Again, be specific.
The answers you were provided with were as specific as the questions asked.
The only dumb question is that not asked.

Snoonyb, life's too short. Enjoy the rest of your day.

If anyone else can elucidate (no pun intended) the matter for me, please feel free!

Thanks.

Thank you.
You've just proved my original suspicion.

"If anyone else can elucidate the matter for me,"

Hi there,

Here are my views/ experiences:

1) Low voltage bulbs generally project less heat than line voltage. They also last longer (even much longer, depending on the bulb). A 50 watt low voltage halogen bulb is a little brighter than a line voltage halogen bulb. Low voltage cans are available in smaller sizes than line voltage.
The con is that low voltage is more expensive- there's a transformer to buy.
But taking into account the smaller size, longer life (up to 20k hours vs 2k hours) less heat projection and brighter light, I always go low voltage when there is a choice.
Now, if you have 30' ceilings, that's a different story. But for most homes, lv works great.

2) Not really. Kitchens are very task oriented. So the cans will be closer together over counter and other work areas to give good overlap and eliminate shadowing. But over walkway areas, they'll be farther apart.

3) Cable and rail halogens do offer a lot of flexibility. You can not only slide fixtures to move them, but add more very easily if needed. There is also a design issue. What do you want to see on your ceiling? I have rail in my hall, but recessed (3" low voltage) in my kitchen.

Basically, every lighting design I do involves low voltage cans. As I'm in California, I'm forced to use LED for kitchens and bathrooms. Which are great units.
But in a design sense, the low voltage allows for the smallest hole in your ceiling without sacrificing brightness or coverage. There are always exceptions, but for the most part, you can light up a room using the same number of 3.5" low voltage halogens as you would with 6" halogens. The light would be the same (if not better) and the overall heat in the room would be much less.

The major fundamental difference is that low-voltage lamps will have filaments that the much shorter and thicker than line-voltage lamps. (P=E^2/R and all that -- with 1/10th the voltage, you need a filament with 1/100th the resistance to get the same watts.)

The shorter filament allows smaller bulbs that have much better control of the focus. Thicker filaments make the bulbs last longer.

Smaller bulbs allow for smaller fixtures.

That's it in a nutshell.

Hey. So that's how it works.

Thanks for that.

Thanks for your answers. I visited a couple of lighting showrooms and found the contrast of light / shadow with the recessed low voltage halogens to bother my eyes. I think what I need to do is figure out what kind of ambient light to install and where, then use the "cans" for task lighting over the counters.

I don't know why, but I find lighting to be really confusing! I feel like I need a class just to understand it all!

Thanks again.

If the recessed lights are correctly placed, there shouldn't be an issue with shadowing. You should have a good overlap of light specifically to eliminate shadows.

The LV bulbs can be harsher if you look at it- as there is a greater concentration of light in a smaller space. But again, with correct placement, this isn't an issue.

For a kitchen, center the recessed lights over the edge of your counters. And remember, the bulbs are available anywhere from a tight spot to a super wide flood. So the bulbs themselves can affect shadowing.

Thanks, lightguy. Maybe the showroom cans didn't have proper overlap. It was the kitchens that were on display, not necessarily the lights. I'll look into the cone angles and make sure they do overlap.

What all of this boils down to is personal preference. We install what the customer wants. Now, that said, I think the halogen lamps are harsh especially if you happen to look at them. We install more 6" cans with IC floods than any other type of can. Incidently, Low voltage cans include the transformer.