It also could be the variety Bronzewing: http://www.esveld.nl/plantdias/43/43223.jpg

Where are you located? That can often help narrow down varieties, because it's an old-but-not-ancient JM, and in many areas of the country there were very few varieties/cultivars available until the last 5-10 years. Also, look into the yard-- is this the only JM, or are there several? If there are several, that ups the chance of it being something more rare...perhaps a collector lived there.

Most common would be Crimson Queen, Garnet, Red Select (I think? not sure), and Tamukeyama. The tricky thing is that each of these varieties has different coloration depending on the time of year and whether or not they're grown in sun, part sun, shade, or full shade. It makes it very difficult to tell what cultivar you have because light makes such a dramatic difference, and leaf shape is so similar. Fall color can sometimes help-- a few varieties will turn orange rather than red in the fall.

Are you hoping to plant a similar one in your landscape? What are the light conditions in the spot where you want it? That might be the best way of achieving your goal. If full sun, you'd want to get something like Baldsmith, which has that dual-coloring in brighter locations but doesn't usually go full red. Crimson Queen, Tamukeyama, etc. will get almost red-purple in full sun. Orangeola will get bright dark red with a tinge of green, etc.

I live in Cherry Hill, New Jersey. As far as I could see, that was the only Japanese maple in the yard. I don't think there are any collectors in my area. And yes, I am hoping to plant a similar plant in my yard. The possible areas I would want it are quite shaded, but I could always purchase another JM to place in an area with full sun.

The only "red' weeping dissectum I have in a lot of shade is Tamukeyama, and it's turned almost fully green at this point. I still love it, but it's not very red at all unless it gets sun. Even then it's very purple-red, which doesn't seem to be what you're going for.

I'd go and do some google image searches, as well as read up on the cultivar-specific threads at UBC, on each of your possible cultivars. The UBC forum is nice because most of their photo threads show the cultivar at different times during the year, rather than at their most brilliant spring or fall coloring the way nurseries do. Esveld nursery is an exception-- their online page often shows some great photos with spring/summer/fall colors. Conifer Kingdom can be good, too.

http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=2370

At this point I'd look into Crimson Queen, Red Select/Inaba shidare, Garnet, Baldsmith, Pendulum Julian, and possibly Orangeola. There are probably several others you could try (there's certainly no shortage of red weeping dissectums), but that's a good start. If I had room for another dissectum, I'd also be looking at Otto's Dissectum. It's more green than your photos, but it has that interesting dual coloration and wow is it pretty--

Here's a list of red or reddish weeping lace leaf JMs:
http://www.davidsansjapanesemaples.com/japanese-maple-tree-selector/?winter_hardiness=zero&summer_hardiness=&tree_size=&tree_form=weeping&leaf_type=dissected&spring_color=reds&summer_color=&fall_color=

Have fun!

Some kind of red dissectum, prob Iniba Shidare, Tamukeyama, Crimson Queen, or maybe even a seedling. About the only thing I CAN tell you for sure, is it is NOT a bloodgood, lol.

I'm leaning towards it being a Tamukeyama because of the way the leaves have smaller offets on the lobes like the subject of this thread does. Also Tamukeyama does appear to get more purplish rather than red if it is in shade.

I have three Crimson Queens and this looks very close to them. All of mine are green where they do not receive sun and this same reddish tint for the leaves that get some sunlight. I have attached a photo from one of my trees.

You can see how confusing this ID thing can be with all the discussion about possibilities just in this short thread. And none of us are close to being experts. LOL!! The differences in cultivars IS very subtle and coloration varies with light conditions (as magpie noted) and with area of the country, so it might make sense just to review/Google the cultivars noted and pick the one you like best. And is easily available.

FWIW, it's hard to go wrong with ANY red weeping dissectum! And like many of us, you start with one and gradually, more keep appearing.........the trees are somewhat habit forming :-))

Definitely confusing! Have you tried asking the homeowner?

Around here, the only red weeping dissectum available for ages was Crimson Queen. With the age of this one, it's doubtful they ordered anything special (ebay, online nurseries, ec.). I think Crimson Queen is probably the most likely and most popular, but I don't know what nurseries were stocking in New Jersey 10-15 years ago.

I'm trying to find a good deal online for a Tamukeyama, like maybe $10 or so, not including shipping. I don't expect to find Tamukeyama in stores, especially after learning that with a lot of Japanese Maples big nursery stores like Home Depot appear to take the labels off the JMs and simply label them as "var Dissectum" or "var atropurpureum". But then again I could not spot a graft union on some of the atropurpureum labeled trees so they could very well have been seed grown.

$10 is almost impossible to find, even for a first or second year tree. Plus you'll be waiting 5 years for it to develop beyond a twig in the ground. You can find 2nd year grafts on ebay for under $20, but it's worth it (in my opinion) to spend the extra $20-40 to get a tree with some shape and size to it. That's less than $5 per year of growth--

" I don't expect to find Tamukeyama in stores, especially after learning
that with a lot of Japanese Maples big nursery stores like Home Depot
appear to take the labels off the JMs and simply label them as "var
Dissectum" or "var atropurpureum"."

Let's clarify this a bit :-) Home Depot, Lowe's and other home improvement box stores are not 'Japanese Maple big nursery stores' -- they aren't even nurseries. They are hardware stores that happen to sell a few plants. They purchase in bulk from regional vendors and there is no guarantee that the plants they offer are correctly labeled or even true to type. Even when they do purchase from big name suppliers, the stock is second grade - not the same as what is offered to independent nurseries or garden centers. It is highly likely that unnamed JM's being sold by them are just seedling maples.

If you want a properly named form, seek out a nursery that specializes in these plants. Most quality plant nurseries/garden centers purchase from reputable growers that verify the provenance of their stock. Ambleside Nursery in Hillsborough is one such nursery but I'm sure there are others located in your area. You can also find quality and labeling accuracy with certain online vendors but the form and structure of the plant to me is as important as the culitvar name so I want to see the plants in person before I buy.

Okay, I will try to look for Tamukeyama at an actual plant nursery, I am aware of a few good ones in my area. Also getting a tree under $50 is important as I am only 17 and still live with my parents, thus I do not have a lot of money. I am attempting to get a job though so I will be able to purchase more expensive trees then. Until then I will have to look for trees that are $10 or $20 or less, not including shipping.