The Front / Back Focus Debate

As mentioned in an earlier thread I have narrowed my lens choice down to two lenses now (at last!)
Namely the Tamron 17 50 2.8 and Sigma 10 20

Is it ok to buy a Tamron 17 50 2.8 that might need a little front focusing and adjusting done to it? I imagine it wouldnt be too much of a prob if I toyed around with it.
Also, when complete does the camera save the I.D. when I swap to another lens?

Thanks in advance
QC

What body do you have?

The Tamron 17-50 does have a front/back focus issue but once adjusted it is fine. The camera remembers the settings for the lens. It goes well with the K-5 and it is very sharp at f5. Wide open is handy for portraits without showing all the creases and spots.

It has a well documented feature that the front element gets loose. Simple fix by prising off a bezel and tightening the screws.


I've had the Sigma too the f4 one and it is great for landscapes etc and sharp too but not as good for general situations. I've sold the 10-20 but kept the Tamron but if I had to have another wide lens then I'd be happy getting a Sigma 10-20 back.

They are suited to different uses but you must already have decided that in the other thread. I'll have a look for it.

I might be buying both

It's for a K5

You'll be fine then, it saves the adjustment.
Good value lenses the pair of them

It would be silly to just buy one, they are complimentary and necessary.

would love to hear any tips or advice with the siggy Doug

Cheers

QC

Advice? There are some excellent wide angle exponents on here, I'm not one of them I carried it about a lot but rarely used it.

A 77mm CPL polarizing filter is not cheap. And apparently you get weird results at wide angles.

Carry a tripod with you, I was using it on a K-7 and needed a bit more help for longer exposures, the K-7 needed working in low light.

A remote is handy too.

I wished I had got a good ND filter for the smokey water and I loved this recent image with an ND10 sizewell.

[IMG]http://i740.photobucket.com/albums/xx49/df8/IMGP1752_zpsccbe0775.jpg[/IMG]
[IMG]http://i740.photobucket.com/albums/xx49/df8/IMGP0830_zps221aa6f8.jpg[/IMG]
[IMG]http://i740.photobucket.com/albums/xx49/df8/IMGP0874_zps73da2c7b.jpg[/IMG]

For the Sigma, my advice is choose the earlier version which is probably the slightly better performer of the two. After obsessive testing at SRS one day, I also thought it was more consistent across the frame than the Tamron 10-24 alternative. You do get a slightly weird moustache distortion from the 10-20, but it rarely gave me any problems and I bet Lightroom probably has automatic corrections available in any case (if you use LR, that is). I thought the Sigma was a very good lens especially for the price, with the bonus of good build quality and a nice case to keep it in. Trouble is, mine stayed in the case most of the time....which is why I don't have it any more

I am happy to be corrected, but I thought the AF Fine adjust feature only recognised Pentax lenses?

Even if I'm wrong, however, using it with a zoom is a compromise; it's really best with primes.

Seemed to work with the Tamron, I hope it wasn't just me fine tuning my wishful thinking?

Zooms are already a compromise. However the correction seemed to work across focal lengths and distances, enough for my average requirements.

Works with non Pentax lenses as well. Only problem with Sigma is they tend to use the same ID number for multiple lenses which can be a problem if you have 2 with the same ID.

Thanks for the correction guys.