I have the 150 (not the 180), but what I have "heard" is tha the 180 is popular because it allows a little more working distance from the subject for the same "shot", and allows (at the distances being equal) the option of getting more of a "head shot" vs a "head & shoulders". Like I said I don't have the 180, but quite a few portrait photographers seem to like it.
Actually, you should consider the 160CB which is much maligned by lens snobs (freaks who look at MTF charts more than images) but which actually, makes wonderful portraits and is very reasonably priced--especially for a new 501 owner.
Joe Suburbs, the post modern hyper rural sub urban anti hero and vertiginous surrealist
Actually, looking at MTF curves, now that you mention it, the 150mm looks like a better performer than the 180mm despite the popular opinions.
The best advice would be to rent each of these lenses and try them out to see which is better for you. You may like one over another based on image qualities. Or the handling of one may be superior in your opinion. Or you just may find a deal on an old lens that you can't pass up.
I use only the 180mm, and I'm very satisfied. I use the extension tube 16, and I can have a smaller distance between me and the model of the picture. The only bad side, for the use that I have, is that it is one heavy and biger lens. It is not possible to take pictures with a speed slower than 1/250, if you don't use one tripod. You can see the pictures that I have on the gallery section.
It looks like there are many lenses for the V-System in the long normal through short telephoto range between 100mm and 200mm. There is the 100mm f/3.5, 110mm f/2 (focal plane bodies only, the fastest medium format lens?), 120mm f/4 macro (the older C was f/5.6), 135mm f/5.6 (bellows or variable tube only), 150mm f/4, 150mm f/2.8 (focal plane bodies only), 160mm f/4.8 (not for most focal plane bodies), 180mm f/4. There are many choices. I personally don't think there really are any bad lenses in this group, but some stand out more than others. The 100mm is my favorite lens in the V-system, but once my 110mm arrives, that may change. The 100mm is probably the best lens at infinity. The 120mm is great closer than 20 ft, though soft at infinity. Since I do not shoot many portraits, you can see my bias to long distance shooting. But there are enough choices depending on ones shooting preferences. Maybe too many.
With all this talk about the 150mm, I had to take it out shooting this afternoon. (Of the lenses mentioned, I've only used the 100mm and the 150mm, and will soon be using the 110mm f/2, as I also use a 2000FCW in addition to my 500C/M. I do plan on getting a 120mm or 135mm for macro work eventually.)
Re depth of field: When producing "same size (on film) head shots" depth of field wil be the same, no matter what lens.
Since medium formats are bigger, a full frame headshot in MF will have higher magnification than the same in 35 mm format. Hence the shallower depth of field in MF. But fill the frame with the same head, using different MF lenses, and you will not be able to notice any difference in depth of field.
The rough (!) 35 mm format equivalent of the 150 mm lens is 94 mm, the same of the 180 mm is 112 mm.
Looking at MTF curves is informative, and ican be quite usefull, but no matter what diferences these curves may show, fact is that both 150 mm and 180 mm lenses are more than good enough. No worries there. Not a deciding matter, in my view.
The 110 mm, by the way, needs to be stopped down to f/5.6 to even begin to come close to the 100 mm. Buy it for the shallow depth of field, and its very own character (which decidedly is a bit soft), but not to compare it to the 100 mm.
The 120 mm, on the other hand, is a very good choice too, if you like the a-bit-closer perspective. I do, but not for tight head shots. A 250 mm lens is my choice for that type of portraits.
While the 110 mm wide open is a bit soft at all distances, the 120 mm, is not (!) soft at all, not even at infinity.
The 135 mm is indistiguishable from the 120 mm, save for the small difference in focal length (not much) and the need (!!!) to use the 135 mm on a bellows or variable extension tube. If you're thinking about getting either 120 mm or 135 mm Makro-Planars, the 120 mm is the one to go for.
CB lenses, by the way, can be used on all post-1957 focal plane bodies except the 202 FA. So "not for most focal plane bodies" really should say "for most focal plane bodies".
I shoot with a 110, and find for tight head shots i dont have the distance i need. i prefer a 150 lens. also you can look through some books on portrait photograpy and study some of the poses. they generally give you exposure info along with the lens type.
For portraits I use the 180mm which is just superb - one of Zeiss' best probably because it is a more modern / newer design.
I found the 150 (also an excellent lens and very popular) not tight enough for my liking, whereas the 180 is just right. Some say the 180 is so good that it can be too sharp for flattering portraits. If this is an issue I use a Softar 1.
By the way I recently added a 250mm to my kit and it is magnificent and very useful for very tight portraits giving good distance from the subject too.
The out of focus attributes are very nice and smooth with both 180 and 250 (similar design and similar time of introduction).
I do use the 80mm lens for occasional informal portraits and it has lovely attributes. Attached is a recent s&le taken without the subject being aware.
Qnu's focal length comparison is accurate whereas the other posted overstates the 35mm equivalents.
I have been using my 501cm kit with the 80mm CFE lens for the last couple of years. I am now at a point where I would like to add one more lens of a focal length greater than 80. Here is my question : if you were in my position and can only buy one lens, would you buy a 120, a 150 or a 180 - and why ?
Thanx in advance for the advice I am sure get from some of you.
I use a 120 s-planar later (macro planar) since it is able to focus close and a 250 sonnar as it is best wide open but I would like to ad a 180
you probably could not go to wrong with either lenses - try them out and se what you like
Kommini, before I answer your specific question, my best advice is that you do a "lens kit plan". Plan each focal length basedc on specific needsw, use, preferred angles of view etc - to logically step out focal lengths that don't unnecessarily overlap etc. Then you just quietly progress to acquiring those in your plan based on priority and budget.
My plan when I bought my 501CM and 80 CFi was to add 50 FLE, 120, 180, 250. Over 5 years I completed my plan and love the fact each has its perfect place and role. I do not regret any; I did not end up wasting money by buying , selling and re-buying etc..
So the first I added was a 50 FLE; second was 180mm; third was 250mm and last was 120mm. You'll see that while I had the 50,80 and 180 there was a "hole" but I know that a few years later I would add a 120. I never had to debate things like 100/120/150? but I have 180 and 150 is too close" etc etc. I think you'll get my point.
The 180 is my preferred portrait - the most amazing resolution and sharpness (some say it needs a softar to flatter women since it is sooooo sharp). I also use it for landscapes. Yep, it's bigger than a 150 etc, but my choice is only based on angle of view and quality of image.
My 120 makro-planar is my "normal lens" and I simply LOVE it.
The 250mm is like the 180 in sensational resolution and sharpness and a favourite for mountainous landscapes.
The 50mm is as wide as I like in 6x6 and a stunning lens (FLE version).
Just to say I am very happy with my 120 macro planar for portraits. Firstly, undeniably the best possible quality results are from tripod mounting, however I can get pretty good images with the 120 lens hand held and it is a bit more spontaneous that way. Secondly if one ever did consider a digital back (Im not exactly rushing) the 120 with a magnification factor built in would still be just about OK wheras the 180 would definately be too long for me. Like anything else personnal taste and subject material dictate your ultimate choice. It is often difficlt to try before buying but if you can you should!