Tamron 17-50 non-vc

Simonmac
Posted 03/02/2014 - 10:48 Link
Hi folks

I would welcome any tips on using this lens.....

I think I stupidly sold an 18-55 Pentax WR and a Pentax 35 2.4 to get this----I am disappointed with the results. Used on a K200D and Kr body.

Thoughts? I don't use wide open, I use a fast enough shutter speed at close to base ISO.

Cheers

Mac
dougf8
Posted 03/02/2014 - 10:56 - Helpful Comment Link
It should be good. Beating the 18-55 and getting close to the DA35. (rebuy the DA35 )

Check the front element isn't loose, this affects focus.

Try calibrating front back focus adjustment. I've had mine at +8 and +max too. Even after a service. I last did mine pointing about 3m from an angled tree trunk, focusing on a knot then reviewing the image and adjusting.


Aperture mode, f5 or f5.6 it should be sharp. If not send it back.
Lurking is shirking.!
Edited by dougf8: 03/02/2014 - 11:01
Simonmac
Posted 03/02/2014 - 11:01 Link
Thanks Doug

I think that the lens just doesn't do it for me as the other lenses mentioned do.

The focus seems fine- I think it's the lack of contrast compared to e prime.

Cheers

Mac
dougf8
Posted 03/02/2014 - 11:11 - Helpful Comment Link
Most if the time I have either the DA35 or DA50 on the front and I'm happy. The Tamron is on if I need a zoom.

You have probably been spoilt by the 35.

The Tamron is a sharp zoom I'll have a look tonight and do a comp at 35mm.

There will be variations in individual lenses. You have checked for haze?
The loose front element can cause oof in parts of the image.
Lurking is shirking.!
dougf8
Posted 03/02/2014 - 12:02 Link
Have a look on photozone.de the Tamron from the nikon dx section. The DA35 is 2478 wide open and 2723 at f4 compared with Tamron at about 2150,

You're spoilt.!

Or is that sensor resolution?
Lurking is shirking.!
Edited by dougf8: 03/02/2014 - 12:02
Simonmac
Posted 03/02/2014 - 19:20 Link
Thanks Doug

Mac
dougf8
Posted 03/02/2014 - 22:14 - Helpful Comment Link
The DA35 is softer than I anticipated at 2.8. The Tamron is sharper than I anticipated at f5!!!! Anyway I could probably do with calibrating them both at the same time and doing it again.

Camera on a tripod, 6 feet away from the books, Live View focus on the Patrick Suskind book, I retook the f2.8 one as I wasn't happy with it. DNGs viewed in Lightroom 3 on a Mac and XY comps viewed at 1:1 pixel resolution and grabbed. So no sharpening. ISO 400 so a bit more to squeeze at 100

From this you should be pretty happy with the sharpness of the Tamron and the contrast ( I know it's flash light ).

If you want the full size files and/or RAWs drop me a PM they are reasonably big.

screen cap of comparison (resized for screen capture).
[IMG]http://i740.photobucket.com/albums/xx49/df8/foo03022014215720_zpse2b385d4.jpg~original[/IMG]

f2.8 DA35 on left, Live View focus on Partick Suskind Perfume book, Flash used, slightly oblique angle to stop reflected flash.
[IMG]http://i740.photobucket.com/albums/xx49/df8/f28version2DA35onleft_zps3c2301d6.jpg~original[/IMG]

f5 DA35 on left
[IMG]http://i740.photobucket.com/albums/xx49/df8/f5da35onleft_zps53259192.jpg~original[/IMG]

The full frame DA35 at f5
[IMG]http://i740.photobucket.com/albums/xx49/df8/IM5G0051_fullpic_zpse4555235.jpg~original[/IMG]
Lurking is shirking.!
Edited by dougf8: 03/02/2014 - 22:29
Pentaxophile
Posted 03/02/2014 - 23:09 Link
Knowing it was you Doug, my eyes immediately scanned the shelf for a Vonnegut book. And sure enough! Not sure why, but had a hunch you may read his stuff.
dougf8
Posted 03/02/2014 - 23:27 Link
Pentaxophile wrote:
Knowing it was you Doug, my eyes immediately scanned the shelf for a Vonnegut book. And sure enough! Not sure why, but had a hunch you may read his stuff.
, the wife is the brainy one, her books outnumber mine 8 to 1, I read vicariously, infrequently, osmotically and I'll read the Vonnegut next. I think the last one I read was "The Road to Wigan Pier" and I've a Carl Hiassen lined up. I mostly read reviews of lenses ..........

We should perhaps have a thread with images of the books we're reading at the moment, or one for what we're drinking etc etc
Lurking is shirking.!
Edited by dougf8: 03/02/2014 - 23:36
Simonmac
Posted 04/02/2014 - 06:10 Link
Thank you Doug

This may be irrelevant but I checked the front element last night and the circular plastic clip that keeps it there I gently pushed and it clicked down in two places. Any thoughts?

Cheers

Mac
dougf8
Posted 04/02/2014 - 09:24 - Helpful Comment Link
I'm mobile so limited.

There are some instructions how to remove the bezel and tighten the screws for the front. Not sure where though.

However if you suspect it's not up to snuff you and the seller might like to agree how to take it forward. No point messing it up. It should be better than the wr kit and slightly worse than the DA35, so you know where your IQ should sit.

Good luck
Lurking is shirking.!
Jonathan-Mac
Posted 04/02/2014 - 11:20 - Helpful Comment Link
This lens is a funny beast. It's sharp even wide open, with great contrast and capable of producing pictures with a nice 3D "pop"

However...

1. Many copies are said to front focus or back focus, and perhaps by different amount depending on the focal length it's set to

2. There is said to be quite a wide variance in quality control, so some copies may be sharper than others

3. I also use mine on a K200D, and certainly with that camera, focus is often wrong. The K200D does not have the most reliable AF, so I blame the camera more than the lens.

With a good copy, when it performs well, the lens is excellent and very useful, but it can be tricky.
Pentax hybrid user - Digital K3, film 645 and 35mm SLR and Pentax (&other) lenses adapted to Fuji X and Panasonic L digital
Fan of DA limited and old manual lenses
Simonmac
Posted 04/02/2014 - 11:33 Link
Comment Image


Took this this morning, far happier!
AndrewA
Posted 04/02/2014 - 12:47 - Helpful Comment Link
I had no issues with mine Simon, it was sharp as a tack, but I have heard others with front / back focusing.

May be worth a calibration?
Andrew

"I'm here because the whiskey is free" - Tyla

PPG link
Flickr link

Add Comment

To leave a comment - Log in to Pentax User or create a new account.



Proudly supporting Pentax User

Samsung Logo Asahi Pentax Logo