[iDon]

Definitely another vote for the 165 LS, both of the 165mm have great bokeh, and the focal distance makes up for the 5ft focusing distance.

keep in mind, that the 165 LS has 5 aperture blades only. After having tried it for outdoor portraits (=nervous backgrounds such as branches or trees and aperture stepped down to let's say 5.6) I wouldn't describe the bokeh as outstanding. I own that lens and I do like it, but it actually is a special application lens. As written before, there are lenses with better magnification for tight head shots.

Pentax 6x7+ extesiontube 1+ 105/f2.4@f/4.0. I took a few images and some @ f/2.4 but then the nose and forehead got out of focus.

I find that this combo makes the model look thinner/skinnier than a Pentax K-3 with the DA*300.

Did you expect, that a tele lens would make look a face look thinner? On the contrary. A tele lens slightly compresses facial features, so a face looks more plain, than it actually is. It's just physics http://stepheneastwood.com/tutorials/lensdistortion/IMAGES/tile1.jpg

[Duplo]

Hello, I was previously using an RZ67 w/ 110mm f/2.8 lens and it was brilliant, I could take neck-up shots and focus on the eyes with no problem. Now I am interested in purchasing a Pentax 67 since I had to sell my RZ67, and was always fascinated by the 105mm f/2.4 lens. Further research into it is quite disappointing as it seems I cannot use it to for close portraits due to its 3.25ft minimum focus distance. Does anyone know what I can do? I read the 90mm is about 2.25ft MFD so that would allow tighter shots, but I also read that it's bokeh quality is not as foggy and smooth as the 105mm's so that's unfortunate.

Do extension tubes diminish image/bokeh quality at all, if I put one on the 105mm?

Example of how close I want to be: http://i.imgur.com/uDcbw2r.jpg

The 105 with a no 1 tube or the 165 LS (with or without a no 1 tube) are the two lenses I use for that kind of images.

with the 105 you ideally want to stop it down a stop or two wide open it will be an eyeballs in focus only kind of thing.
here it is wide open at minimum focal distance with a no. 1 tube:

keep in mind, that the 165 LS has 5 aperture blades only. After having tried it for outdoor portraits (=nervous backgrounds such as branches or trees and aperture stepped down to let's say 5.6) I wouldn't describe the bokeh as outstanding. I own that lens and I do like it, but it actually is a special application lens. As written before, there are lenses with better magnification for tight head shots.]

The 165 LS is indeed a specialty lens, but unlike you I have found the bokeh to be very pleasant and quite uniform, especially if you work around the minimal focus distance of the lens, now I mainly shoot bæack and white film, thus results with colour film may show different out of focus aspects of the lens:
This is what I have come to expect from it:

[Silent Street]

Take a 165mm f4 (or the squat 90mm) leaf shutter lens along for a ride. This is what I use for portraiture (but it's used latterly in a landscape context). I also use the 75mm f2.8AL at a much closer distance but the killer quality of that lens is such that every fault in skin and colour will be shown whereas you can frequently get around that with the 165mm. The 105mm is a very old, very ordinary, very pedestrian, albeit still unimaginatively popular lens. A leaf shutter lens will also allow higher sync speeds with studio lights if that is your set up.

[ppohja]

Here's the results for my small test. I took the lenses mentioned here that I happen to have and took a test shot of a test subject at the minimum focusing distance of each of the lenses. I happen to have the 165mm f2.8, 135mm f4 macro and 90mm f2.8 lenses. In addition, I happened to find the T132 close focusing filter, which I also used on top of each of the lenses. All of the shots are made at f8 and 1/250, handheld. Focusing made by setting the lens to its minimum focusing distance and feet-focusing to the area of greatest contrast under the test subject's chin.

Used Ilford delta 400 film and the scan was made by placing the negatives on the glass of the flatbed scanner (Epson 4990), as I don't happen to have the negative holders for this scanner. So this is not certainly a lens quality test, but gives you an idea of how close can you get to your portrait subjects.

First, 165mm:


Second, 165mm + T132:


Third, 135mm macro:


Fourth, 135mm macro + T132:


Fifth, 90mm:


Sixth, 90mm + T132:

[tuco]

... the scan was made by placing the negatives on the glass of the flatbed scanner (Epson 4990), as I don't happen to have the negative holders for this scanner.

That scanner does not have auto focus. So theoretically it should have had its focus set for film height while in the negative carrier, FYI. But sometimes that is not even right but yours look pretty good for lying on the scanner glass.

[gofour3]

Here's the results for my small test. I took the lenses mentioned here that I happen to have and took a test shot of a test subject at the minimum focusing distance of each of the lenses. I happen to have the 165mm f2.8, 135mm f4 macro and 90mm f2.8 lenses. In addition, I happened to find the T132 close focusing filter, which I also used on top of each of the lenses. All of the shots are made at f8 and 1/250, handheld. Focusing made by setting the lens to its minimum focusing distance and feet-focusing to the area of greatest contrast under the test subject's chin.

Used Ilford delta 400 film and the scan was made by placing the negatives on the glass of the flatbed scanner (Epson 4990), as I don't happen to have the negative holders for this scanner. So this is not certainly a lens quality test, but gives you an idea of how close can you get to your portrait subjects.

First, 165mm:


Second, 165mm + T132:


Third, 135mm macro:


Fourth, 135mm macro + T132:


Fifth, 90mm:


Sixth, 90mm + T132:

Nice work and good information!

Phil.