This is interesting as I already have the 50 1.4

I know nothing about teleconverters - I presume the increase the focal length. Is there a reduction in image quality and is the DOF affected?

How much are they?

How much is one of those teleconverters?

You will have some perspective distortion creeping in if you shoot a head shot, but it's not a bad portrait lens.

Check out this link and look at the images attached to it, bear in mind that these were on full frame so you'll need to make the mathematical adjustment for your crop sensor.

link

As you can see at 75mm (your 50mm on a crop sensor) you are right in the area where distortion is on it's way out but it's still noticable.

It looks like I really need the 70mm Ltd.... but some other cheap options to look at before I can justify the cost of the 70mm, is there such a thing as "just one more lens" as I've been saying that for about a year...

What I do like is the technical expertise on this forum, I asked a similar question on talkphotography about a year ago and then had to spend about 12 pages of posts trying to explain what perspective distortion was...

Yes, at 50mm on a crop sensor the distortion is just about disappearing, but can still play havoc with facial features and can be unflattering.

I just need something a bit longer but not that long that I am restricted with movement if in a tight environment.

Very interested in the Voigtlander 58mm but the ones I see on eBay are new - is there a previous (cheaper) model as these aren't cheap.

My light use GX20 body, which is virtually the same as a K20D, for a 70mm ltd lens. Negotiable cash amount to lens owner.

Hi Jak, I'm using a K5 so it's a cropped sensor so the 50mm is a 75mm equivalent. At this focal length I will get a small amount of distortion to the face and it is quite noticeable on the nose.

It's not far off being OK but not quite good enough. I don't want to shoot from further away and crop as I will lose resolution and the DOF won't be the same.

I need around 85mm and above ideally to create the most flattering portraits.

I have the 18-55 kit lens, and it's not bad for a cheap lens but it certainly isn't a great portrait lens to be honest.

Thanks, I'll check those out. I can't use my 50mm for close up portraits as I get perspective distortion with it being slightly too wide.

What does the NM mean? Is this one of these - link

And if so, that's probably a bit more than I can afford at them moment.

Thanks guys, can you give me the details of these lenses so I can look them up on ebay please? i.e. manufacturer/model.