50mm, 1:1.4 or 1:1.7????

dave sz · 02-07-2007, 08:28 PM

which one? I 'm having a hard time deciding. I can wait for the 1:1.4 to come around at a good price, or I can get a 1:1.7 for much cheaper than the 1:1.4 ever could sell for. This will be for mostly indoor shots where the lighting isn't too great......

**Adam** · 02-07-2007, 08:32 PM

The F1.7 50mm's have been claimed to be a bit sharper, but if you want the extra speed, go for the F1.4.

dave sz · 02-07-2007, 08:35 PM

sharper? really? How much of a difference would the half stop make with indoor shooting? If I could shoot at f1.4 with a 1/100 shuter speed, what shutter speed would I have to use to get the same exposure witht he f1.7? Or can that not be really predicted?

**Adam** · 02-07-2007, 08:45 PM

1/125s F1.4 = 1/90s F1.7

Not a bit difference, but sometimes it helps.

dave sz · 02-07-2007, 08:49 PM

yeah, that is a bit of a difference. I really want the 1.4 for but I dunno. I can get a 1.7 for <$50 while the 1.4 will cost me around $100.
Are all the 1.4 good or do most people only consider the pentax ones that great? I see some takumars and ricohs as well...

Jonas B · 02-07-2007, 08:58 PM

Originally Posted by Mo

The F1.7 50mm's have been claimed to be a bit sharper, but if you want the extra speed, go for the F1.4.

It has been claimed so, yes. However, I can't agree with those saying so. When stopping down the 50/1.2 or the 50/1.4 so the lenses are compared at the same aperture you'll be hard pressed to claim anything about resolution differences.

Otoh I can see differences when it comes to bokeh where I would say that they can be sorted as follows: A50/1.2, K50/1.2, A/F/FA50/1.4 and finally 50/1.7.

The A50/1.2 may have a somewhat higher contrast than the K50/1.2 and the little difference in bokeh may be thanks to the added aperture blade (nine blades instead of eight).

People who are more into macro shooting usually say that the f/1.7 version has a somewhat flatter focus plane which is an advantage if you shoot stamps using extension tubes.

If we stop the peeping show and instead have a look at real use pictures they are all pretty much the same with a slight advantage to the faster lenses thinking of bokeh differences.

Well, that's my view of the matter.

**Adam** · 02-07-2007, 09:02 PM

I have the A F1.2, and I'd agree with you on the bokeh. It's tack-sharp if you get the focus right, too

People probably say that the F1.7 is sharper because of its slightly larger DOF, which in practice renders most daily photos sharper.

Jonas B · 02-07-2007, 09:02 PM

Originally Posted by dave sz

yeah, that is a bit of a difference. I really want the 1.4 for but I dunno. I can get a 1.7 for <$50 while the 1.4 will cost me around $100.
Are all the 1.4 good or do most people only consider the pentax ones that great? I see some takumars and ricohs as well...

What is USD50 to argue about after some thousands of pictures?

First decide if you need AF or not, then if you need automatic aperture or not. Or in the opposite order maybe... If you need AF you don't have a lot of choices. If you can live with stopped down metering and manual focusing I think I would go find a good multicoated Takumar.

Jonas B · 02-07-2007, 09:09 PM

Originally Posted by Mo

People probably say that the F1.7 is sharper because of its slightly larger DOF, which in practice renders most daily photos sharper.

Or they compare one lens used wide open with another lens wide open. Both resolution and contrast increases while stopping the fast lenses down. You also have some halation and axial CA with the faster versions that you don't see to the same amount with the slower versions.

Using the fastest lenses around wide open will probably always be a hit or miss thing when snapping away. With some care and afterthought (?) you get those pictures that are hard to mimic with standard lenses, or with PP.

There is a reason many Canon shooters (incl myself) love the new EF50/1.2 despite the freakn price of that thing. AF problems and weight... well, in my case I forgive the lens instantly.

regards,

dave sz · 02-07-2007, 09:24 PM

Originally Posted by Jonas B

What is USD50 to argue about after some thousands of pictures?

First decide if you need AF or not, then if you need automatic aperture or not. Or in the opposite order maybe... If you need AF you don't have a lot of choices. If you can live with stopped down metering and manual focusing I think I would go find a good multicoated Takumar.

well, I already know I'm getting a manual lens, no question about that. Just not sure if all the manual 1.4s are the same......

ahhh, all the takumars I see are screwmount........

clm · 02-07-2007, 10:00 PM

Originally Posted by dave sz

ahhh, all the takumars I see are screwmount........

....but you can still use them with an adapter.

dave sz · 02-07-2007, 10:07 PM

I know, I didn't want to resort to that if I didn't have to though.....

dave sz · 02-07-2007, 10:23 PM

ehhh, the hell with that. Just ordered a multi coated takumar from keh and the adapter off ebay...........

Jonas B · 02-08-2007, 12:19 AM

Way to go! Congrats, really!
It's a different way to handle the lens and camera combo making for another way to approach the process of capturing a picture. With some practise it works surprisingly fast.
If you ordered an original Pentax adapter there is a way to permanently attach it to the lens making it possible to switch the lens the same way as you do with the K-mount lenses.

JJJPhoto · 02-08-2007, 07:14 AM

I've used 50mm f/1.4 lenses from several different manufacturers on several different cameras (film and digital) and I don't think there's a better 50mm f/1.4 lens than the family of Pentax SMC 50mm f/1.4 lenses. The FA 50mm f/1.4 is my go-to lens for available light work.