Lens advice needed.... 28mm, 50mm, or 85mm?!

Hi guys!

I plan to buy a lens, for indoor portrait photography, sadly my budget is very limited until summer, so I can only buy one.

Its gonna be a Prime lens, I only can't decide wich one.
(I will use it on a 40D, later (summer) on a 7D)
So these are the possibilities:
28mm f1.8 USM
50mm f1.4 USM
85mm f1.8 USM

I do think, that the 85 is a bit too long for indoors, but on the other hand, the 28 might be a bit too wide.
The 50mm could be good, but sometimes I need to go too far from the model.
I in fact own a 50mm 1.8, and I am stunned, how nice pictures it makes.

The 85mm on the other hand would be absolutely great for outdoor portraits too...

So I really can't decide.

Should I switch my 50 1.8 to a 50 1.4?
Shlould I keep the 50 1.8, and buy a 28 1.8 too?
Or should I keep the 50 1.8, and buy a 85 1.8?

I am open for suggestions.

I also have 2 flashes, (580 EX II, and 420EX, both with gary fons Lightsphere). so light should not be a problem...
I also have a 28-70 f2.8 L, sadly its optically not perfect anymore,
so i get hazy pictures... No way to repair it

The place I plan to shoot in is a 4-star Hotel, where thanks to one of my friends, I can shoot free of charge.

When I was using a 7D the most useful portrait lens was the 50 followed by the 85. Rarely used the 28.

For portraits on a crop, you will find the 50 & 85 useful in more situations than a wider lens. The 85 is my preferred lens for portraits and I also use my 70-200 (at the 200 end) a lot for outdoor portraits ... but this is the look I prefer. You are correct that the 85 might be a bit long for indoor portraits unless you have plenty of room.

You didn't mention whether you have a zoom but if you have access to one that covers those ranges (i.e. the 28-135 kit zoom) you could try various settings to see which focal length(s) suit your needs.

The 50 1.8 is a very good lens, especially for the price but for portraits you might want to take a closer look at the 1.4 ... I think I read in another thread where the 1.4 is currently on sale (? Canon refurb store). I've bought from the refurb store and can recommend it for the cost savings. I've also bought used without issues. So you have lots of choices ... good luck on your search.

I recommend the 35F2. It is less expensive than the 28 F1.8 and it works fine at F2 or F2.2. AF is fast and accurate. Image quality is great. I also recommend getting a hood for the 35 or 28, if you go that route.
I also have the Canon 50 F1.4 and 85 F1.8. I use the 35F2 much more inside the house. It is selling for a good price at Amazon, the last time I looked.

Thanks guys, for the replys.

I too tought about the 35 f/2, but I am still not sure, the 28 f/1.8 is more "sexy" to me

The 35mm F2 on amazon is on sale for 289