Pentas DS not working with Sigma EX 105mm Macro

Help! I have two Pentax DSs and my Sigma APO 135 - 400mm and 28-105 work in all modes with the cameras. My Sigma EX 105 Macro does not. All lenses work perfectly with the PZ1 and the the ZX-5N. Any idea as to why the macro lense does not work with the DS?

Regards,


Alchemist

Buy Sigma at your peril. I have a Sigma lens (which I haven't used for years) which works with a Z1-P but not with an SF-X. Why? Who knows?

The focussing ring on another Sigma lens (bought new) is attached by means of double-sided tape. Not a screw in sight. I discovered this when it refused to focus properly.

Some people claim that Sigma lenses are OK, and perhaps the more expensive ones are. But the cheaper ones are best avoided.

G

I have been using the Sigma 105 EX Macro with my DS2 for 10 months with absolutely no problems. I also have Sigma 170-500 and 70-300 APO Macro which also work flawlessly with the DS2,

What problems are you having with the lens on the DS?

Mike

Mike,

The lense appears not to be communicating with the camera. I cleaned the contacts and no change.

When placed on the camera, no matter in what mode, Av, Tv, P,M, B, or Auto Picture, the LED display does not communicate with the lense. Tried this on both DS bodies. Other Pentax and Sigma lenses work fine. The 105 Macro lense is then placed on a ZX-5N and works fine.

Regards,


Alchemist

From what I've read on the 'net, Sigma reverse engineer the communication protocols between the body and lens (rather than licensing the protocol from the body manufacturer). Consequently, they sometimes get it working with then-current bodies only to find that they haven't implemented the protocol to the original specs and the lens doesn't work on newer bodies.

Sounds like that's what you've got there...

Except, the film cameras you mention have dual communication with the lenses. The older bodies used the metal finger to sense where the aperture ring was set to - you'll see the finger moving if you take the lens off the body and rotate the aperture dial.

However, the Pentax DSLRs dispensed with that approach and rely solely on the electronic contacts.

You may find that the electronics inside the Sigma are defective and so cannot communicate with the body, but the lens appears to work when used on an older film body (because it's using the mechanical coupling instead).

Hope that may shed some light on the problem...

Matt

And whilst any Sigma lens MIGHT work with a current Pentax body, there is absolutely no guarantee that it will work on a new generation one.

G

What Matt says about the defective electronics seems to make sense. I have tried my Sigma 105 with all the settings I could think of on the lens and DS2 that might cause the problem and it works fine - also fine on my MZ6.

Sorry I can't be of any more help.

Mike

I have an ist Ds but find the pentax lenses pricey. I have no problems with my Sigma lenses, my favourite being a 28-80 macro at 1:2 which is a great walkarounder.

There is also a much wider choice available.

Hi Alchemist,

I reckon Matt's right (again ). I've been using this lens on my istD for a year or so with fantastic results (if I say so my self ), so don't let it put you off.

Might be worth seeing if a repairer could have a look, if it just needs an internal clean of contacts etc, the bill might be worth it.

Can you still use it manually - ie. setting the aperture via the ring on the lens, and manually stop-down metering? It's not ideal, but at least you'd be able to use the lens. You'd probably need to select the appropriate setting in the menu to allow the camera to function when the aperture was anything other than 'A'.


George, you always bring a smile to my face - can I start calling you 'Prophet of Doom'? I think there are a lot of happy Sigma users out there, including myself (24mm, 105mm macro and 10-20mm, all solid, sharp lenses, admittedly EX ones too, apart from the 24mm). There are bound to be issues with 3rd party lenses sometimes, which obviously isn't good, but just as there are mediocre sigma lens, there are the less than ideal Pentax ones too. And, as Downswood says, there is a much bigger choice from Sigma than Pentax, especially at the extremes of focal length.

But as ever, each to their own. If you feel purely Pentax is the way to go, that's the way for you to go.

Dan

Daniel,

My views are coloured by my bad experiences of (admittedly cheap) Sigma lenses. I've no doubt that the better ones are quite good, but I don't propose to let Sigma off the hook for some very shoddy workmanship.

Apart from the kit zooms, Pentax lenses are usually better than third party lenses, and although there is a temporary interruption to supply of new long lenses, the second-hand market provides ample choice if you can wait for the right lens to come along.

The main reason I haven't bought a lens for a while is not my iron will, nor a shortage of funds (that's never stopped me), but the fact that there is nothing I particularly want, having spent several years building a reasonable collection.

I will, however, be tempted by the 16-50 1:2.8. Successfully tempted.

G
Sorry, Prophet of Doom

Message deleted

Sorry. Going mad.

G

George, I can well see how you could be put off by some double sided tape , hopefully there's none lurking in any of mine.

When I fancied a longer telephoto (300mm), with a large aperture (preferably f/2. I set about keeping an eye out - saw a S/H Pentax one at Ffordes, for (I think) £3000 'as seen'. I ended up going for a Ebay Tamron for £300. I don't use it that much, but I'm happy with it when I do. As I was a Velvia user at the time, the large aperture was a real bonus - these days I'd probably be happy with f/4 (or 4.5 ). Still, it works a treat with my 1.7x AF adaptor.

If there's one lens I want at the moment, it's a longer macro, in the 180mm area. As far as I can see, that only leaves me with the Sigma/Tamron option. Having said that, I do wonder if I really need a longer macro - should I go for the 50-200DA and save myself a bad (worse) back...?

Hope you've found your sanity again.

Dan

Daniel,

I have the SMCP-F 1:4.5 300mm, and it is truly lovely. Very hand-holdable, and with an excellent built-in tripod mount. It cost me £400 in excellent condition. I certainly couldn't justify the 1:2.8.

Having said there were no lenses I particularly want, I have to say that the FA 200mm macro is allegedly quite wonderful; but I have the 1:2.8 non-macro, and don't do enough macro or telephoto shooting to justify the macro version.

The FA 600mm would be an acceptable Christmas present, of course.

G

Sent the lens into Pentax USA. They said it was out of warranty, but fixed it for free. The contact was defective. I am very pleased that Sigma stands behind their lense line. The macro photos are as sharpe as those from my manual focus Pentax.

Regards,


Alchemist