[jk333]

Hi All,

I bought a 50mm f/1.7 Pentax M lens for a wedding and also for a test lens to see if I would actually use/like a 50mm prime. Turns out, I absolutely love it for portraits but I would really like one that autofocuses and is silent. I missed a few shots at that wedding because I couldn't manually focus fast enough and I also noticed people were reluctant to stand still for too long, so I would really benefit from an autofocus prime.

I've got my eye on the Pentax DA* 55mm f/1.4, but the Sigma 50mm f/1.4 seems to have had brilliant reviews and not a bad word said about it.

My only problem is that everywhere seems to be out of stock of it, or has it listed as "on backorder" for a Pentax fit. Is it not available yet? Has anyone managed to get hold of one?

Here's a review of a Canon fit - Sigma AF 50mm f/1.4 EX DG HSM (Canon) - Review / Test Report - excellent sharpness wide open and CA is controlled very well.

Why don't you just buy my 50mm -F- f/1.7... It autofocuses. Don't know about silent, its pretty much standard for sound pentax lenses make focusing.

90 bucks? pm me if ur interested. Its in standard condition, i think good. Came with a film camera I bought awhile back, used. Since I got it, its had a filter and camera or lens cap on it. I use a 24-60mm lens mostly now, so its getting less usage.

[dave9t5]

Hi All,

I bought a 50mm f/1.7 Pentax M lens for a wedding and also for a test lens to see if I would actually use/like a 50mm prime. Turns out, I absolutely love it for portraits but I would really like one that autofocuses and is silent. I missed a few shots at that wedding because I couldn't manually focus fast enough and I also noticed people were reluctant to stand still for too long, so I would really benefit from an autofocus prime.

I've got my eye on the Pentax DA* 55mm f/1.4, but the Sigma 50mm f/1.4 seems to have had brilliant reviews and not a bad word said about it.

My only problem is that everywhere seems to be out of stock of it, or has it listed as "on backorder" for a Pentax fit. Is it not available yet? Has anyone managed to get hold of one?

Here's a review of a Canon fit - Sigma AF 50mm f/1.4 EX DG HSM (Canon) - Review / Test Report - excellent sharpness wide open and CA is controlled very well.

Big G,

You didn't mention the aperture you were shooting...but if it was at f/1.7~2.0 when you missed the shots you may consider these points:
1) The DOF is extremely limited, so focus is absolutely critical. I'm not sure that AF would totally resolve that issue, perhaps others can comment in that regard.
2) If you are using the stock focusing screen that came with the K10D, then it can't resolve less DOF than f/4. A split-image focusing screen is the way to ensure accurate focus.

A split-image screen + a bright 50mm is quite quick and accurate to focus and stopped down to f/2.8 adds enough DOF.

You may want to eliminate these variables before dropping a big sum on an expensive lens.

In autofocus, I would choose the DA*55 for one simple reason: quick-shift focusing. This killer feature is the best of both worlds.

[tenpointnine]

Some shots from the last few days. K20D+Sigma 50mm f1.4
PP in Aperture 2. A tiny levels adjustment, no sharpening applied.




Larger images in Flickr

[asdf]

Some shots from the last few days. K20D+Sigma 50mm f1.4
PP in Aperture 2. A tiny levels adjustment, no sharpening applied.

It's definitely a keeper.

[tenpointnine]

It's definitely a keeper.

Oh yeah

[axl]

those look really promising,
how is AF on K20?

[tenpointnine]

The HSM AF on the Sigma is pleasant to use. I've not measured it but it feels quick and quiet compared to my other, non-HSM lenses.

[ll_coffee_lP]

Looks very good!

c[_]

[kristoffon]

Fast autofocusing isn't synonymous with HSM. I have the FA 50 and on the K20D it focuses VERY FAST. Doesn't leave anything wanting for an HSM lens. So I'd get that if I were you since the FA 50 is so cheap.

[asdf]

Fast autofocusing isn't synonymous with HSM. I have the FA 50 and on the K20D it focuses VERY FAST. Doesn't leave anything wanting for an HSM lens. So I'd get that if I were you since the FA 50 is so cheap.

The OP was concerned about performance wide open. That's why he asked about DA* 55 f/1.4 and Sigma's 50 f/1.4 HSM--both of which perform better than FA 50, wide open (I have the FA 50 f/1.4 and the Sigma on my desk right now, btw). BTW, I don't think the OP is interested in an AF fast fifty anymore, anyway.

[Big G]

Big G,

You didn't mention the aperture you were shooting...but if it was at f/1.7~2.0 when you missed the shots you may consider these points:
1) The DOF is extremely limited, so focus is absolutely critical. I'm not sure that AF would totally resolve that issue, perhaps others can comment in that regard.
2) If you are using the stock focusing screen that came with the K10D, then it can't resolve less DOF than f/4. A split-image focusing screen is the way to ensure accurate focus.

A split-image screen + a bright 50mm is quite quick and accurate to focus and stopped down to f/2.8 adds enough DOF.

You may want to eliminate these variables before dropping a big sum on an expensive lens.

In autofocus, I would choose the DA*55 for one simple reason: quick-shift focusing. This killer feature is the best of both worlds.

Good advice thanks.

I was shooting at f/1.7 and f/2.8.

The shots I was having a problem getting where when my sister was walking down the isle because I couldn't focus quickly enough with the manual lens to get it as sharp as I wanted.

The OP was concerned about performance wide open.

Yes that's correct, the speed of the autofocus isn't much of a concern, as long as it's not overly slow of course! The wide open performance was more important, and this Sigma certainly looks like it won't disappoint.