Objective Lens Reviews

I am a new member to this forum which I have regularly browsed in the past and gleaned much interesting information. I must admit that my only experience with Pentax cameras is my SP500 which has been a very little used backup camera to my Canon A1/T90. As the T90 (21 years old) and my eyesight are showing their age I am looking into purchasing a DSLR.

Being a Canon user my first thoughts were Canon, but soon discovered how well specified and good value for money the K10D is. So it is 99% certain that I will buy a K20D or GX-20 - that's the easy decision! Not so easy is choosing the right lenses, which brings me to my question: does anyone know of any source which objectively compares Pentax/Pentax fit lenses particulrly with regard to image quality?

I know that the Pentax/Samsung kit lenses are pretty good and probably superior to Canon/Nikon offerings which is one good reason for buying a K20D or GX-20. However, a lot of my photography is of trains taken at around 50mm focal length (35mm equivalent) so I need a fairly fast lens and so, despite its cost, I am considering the 16-50mm f2.8 lens. And if you have a weatherproofed camera why not have a lens to match? But how much better is the 16-50 compared to the 16-45 or kit 18-55?

If the Mk2 18-55 is better matched to the K20D wil the 16-50 be still as good?

For convenience I am also considering a superzoom such as the Pentax 18-250, Sigma 18-200 or Tamron 18-250. Again does anyone know of any objective comaprison between them? And which is best in compared to the kit 55-200 lens?

Apologies for the ramble and all the questions. Thanks in advance.

Jonathan

Hello and welcome.

When you ask "how much better?" I think the caveat will be "for what purpose?" If you are used to using mainly a 50mm fast lens then perhaps the 31mm Limited would be ideal for you, albeit expensive.

If you are using the web and printing small prints then the 18-55mm kit lens could be more than you'll ever need, although not a fast optic of course. In fact, you can make excellent A3 prints from this lens.

The 16-45mm and 16-50mm lenses are faster and a definite step up and will be more useable wide open. Stopped down the difference may well be hard to see.

I agree about the weather sealing and if this is an issue then your path is much clearer.

If quality is your criterion then forget the superzooms, which will not be as good and also be very very slow, especially at the long end.

Why not start with the 18-55mm, a bargain in a package with the body, and see how you get on with it. After a while it may become more obvious what your next step should be.

John,

Thanks for your very prompt and thoughtful reply. As cost may well be an issue it's good advice to see how I get on with the kit lenses.

Partly answering one of my own questions PopPhoto.com do provide review data which might be useful to compare lenses

Jonathan

Photozone are quite reliable in their testing procedures (www.photozone.de/Reviews/Pentax%20Lens%20Tests) but lab testing alone doesn't tell the whole story. For real photo examples have a look at the Pentax Photo Gallery (www.pentaxphotogallery.com) where you can search images by lens used, or similarly I find PBase (www.pbase.com/cameras/pentax) very useful.

If you're after a fast "normal" prime and find the cost of the 31 Limited a little daunting (nobody will blame you!) then don't forget to check out the FA35/2 which can still be had new from a few vendors at around the £200 mark, or the new DA35/2.8 Macro Limited which you won't find any reviews for yet (I don't think it'll hit the shops for a few more weeks) and should be around £260-300 when it does.

Welcome to the forum by the way.

Not forgetting the sister site to this one:

www.photodo.com

www.photozone.de

I guessed that from your username

It's well worth owning a Pentax or Samsung DA 18-55mm, even if you intend to get a better or faster lens as well. It is so light and portable that it will be the most practical option sometimes. The low value also makes you less worried about damage and theft.

I like the Pentax 16-45mm F4. Compared to the 18-55, it provides a brighter viewfinder, nicer colours and less distortion, as well as being sharper when wide open. It's lighter than many other good-quality options too.

For more speed, add the soon-to-be-released Pentax-fit version of the Tamron 17-50 F2.8 to your list of lenses to lust after.

Meanwhile, a second-hand Pentax F 28mm F2.8 might be useful if you can find one. Also consider a Pentax 50mm F1.7 or F1.4 if a fast moderate-telephoto would be any use.

Most reviews place the Tamron/Pentax (basically the same lens) above other superzooms. I have one and it is fine for A4 prints, just a bit soft at its longest end. I also have the 55-200 but I have not done a direct comparison.

As to standard lenses - the 35 F2 is an obvious choice - fast, relatively cheap, and razor sharp.

If you did want the F28 2.8 I have one which I barely use (in fact I tried to sell it on ebay last August but the buyer never paid up- and then I moved to Italy and. never got round to relisting it) It is a perfectly decent lens though generally regarded as 'good' rather than 'excellent'

Thanks to all for the links and information - greatly appreciated! Now to digest it all. I will also be able to experiment with my existing pentax screw mount lenses if I find an adapter.

Any other railway photographers out there? Most seem to be of the Canon/Nikon persuasion...

The general consensus seems to be that you need the genuine Pentax adaptor, it allows infinity focus (not all 3rd party ones do) and there are stories out there of lenses getting stuck on bodies with some of the cheaper ones. I don't actually have/use one so I'm just repeating what I've heard.

SRS have genuine ones for £19.99: http://www.srsmicrosystems.co.uk/index3.asp?id=574&Page=2 (bottom of the page).

If you already have some good screwmount lenses then the addition of the kit lens may be all you need.

Like others, I'm a fan of the 18-55 and pictures from a shoot at the weekend I could detect no difference at 50mm and f8 between it and a much lauded 50mm/1.7! Buy it and enjoy it. The genuine Pentax M42 adapter is the way to go but do be aware that you lose automatic diaphragm and have to stop down with the lens's little switch.

I find the 18-55 and the DA 50-200 a great combination