A few q's about the Sigma 30mm, eBay and Sigma sevice before I buy...


vincechu

Link Posted 27/05/2011 - 15:30
Hi everyone,

I've just noticed GW camera on ebay has a very good price for the Sigma 30mm f/1.4 - its 299.99 and with full 3 year Sigma warranty, this is a full 70-80 cheaper than other retailers, so I guess I'm feeling a little cautious, perhaps overly lol

1. Has anyone bought anything from Great Western Cameras before? If so what was the experience like?

2. If I need to get the lens adjusted and sent to Sigma UK, whats the turn around like? (I know I can do in camera adjustment, but just in case)

3. If I get a bad copy, is it normal practice for retailers to refund/exchange?

4. If something goes wrong, for example they refuse to refund, can I use buyer protection on ebay to get my money back? (I did do some reading up, but was a little confused, it seems buyer protection's used for if your goods don't turn up at all? :S )

Have to say I might just save myself any risk and buy from SRS, who have been very helpful and great with me and my K-5 and other purchases in past.

Thanks in advance

PS I know I'm being overly cautious, but as I'm sure you can understand, I dont want that 300 to go to waste Guess I'm also affected by the good/bad copy or bf/ff stigma that Sigma have got from forums.
Vince

bretbysteve

Link Posted 27/05/2011 - 16:39
Just on point three:

There has been an explosion of users on web forums claiming they have a 'bad copy' of a lens. This is largely users who frankly do not fully know what they are doing..many web stories are false. This leaves sellers in an impossible situation sometimes.

A thread on here recently had many users on here saying they had never had any so-called 'bad' lenses in 25+ years on lens buying.

Also, AF lenses are just not as well made, or made to anywhere like the tolerances of older manual focus lenses. The pixel peepers (who IMO are quite bonkers) have made life very difficult for many people.

cheers Steve

vincechu

Link Posted 27/05/2011 - 16:43
Thanks steve, I completely know what you're saying. I've never had a bad copy of a lens too. looking at some out of focus shots with the Sigma 30mm 1.4, it looks like a lot of it is user error, some people have done focus and recompose, which doesn't work well with the thin dof that 1.4 gives.

Though real bad copies are rare, I guess I kind of want some kind of reassurances, just in case.
Vince

Pentaxophile

Link Posted 27/05/2011 - 17:06
bretbysteve wrote:
There has been an explosion of users on web forums claiming they have a 'bad copy' of a lens. This is largely users who frankly do not fully know what they are doing..many web stories are false. This leaves sellers in an impossible situation sometimes.

OTOH decentred lenses are not that uncommon, Photozone.de has certainly tested a few decentred pentax zooms, and I've had a kit lens that was decentred (went straight back to Clifton Cameras) as well as a 16-45mm which was noticeably softer on one side - although that issue may have developed over time with the inevitable minor knock here and there. It definitely is worth thinking about if you are buying new IMO, and it's one thing that puts me off buying from overseas.

If you are concerned check out the company's returns policies, although you should be well covered if they are in the UK.

bretbysteve wrote:
Also, AF lenses are just not as well made, or made to anywhere like the tolerances of older manual focus lenses.

This is definitely true, I briefly owned a 21mm Ltd, and didn't really feel it was up to K or M build quality, although it was really nice for a modern lens.
[link=https://500px.com/will_brealey/[/link]
Last Edited by Pentaxophile on 27/05/2011 - 17:07

Smeggypants

Link Posted 27/05/2011 - 17:20
1] A lot of people don't calibrate the Camera's AF for their lenses

2] You can't see f1.4 DOF through the viewfinder, so manul focussing is a bit hit and miss

3] and, as said, focussing and recomposing isn't good at 1.4



.... so it's easy to see why lots of reports of soft fast primes come out.

Quote:
uess I'm also affected by the good/bad copy or bf/ff stigma that Sigma have got from forums.

Pentax lenses bf/ff just as much. just calibrate the camera
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283

johnriley

Link Posted 27/05/2011 - 17:59
There are a few issues there that are interesting.

Decentering: I've seen decentering figures in the past and even 15% decentering can give good results, depending on the actual lens design. It may be less than the potential, but a great lens decentered 15% will be better potentially than a poor design decentered 2%. It will be worst with complex lenses of course, all other things being equal.

Manual focus: I can't agree that f1.4 lenses are difficult to focus, that one's a complete mystery to me. The limited DOF means that the sharp point snaps in and out beautifully and alo the brighter image makes it easier as well. When you stop down to f8 or whatever, all that's happened is that the focusing has been as accurate as it possibly can be. I think the problem is more that at f1.4 the point of focus is very precise and if the camera wavers to and fro or the subject moves focus will be instantly lost.

Calibrating AF: So far, no need found. Lenses snap visually into correct focus, even close up. Having the option is excellent, although i would have a slight concern that the correct point of focus may vary depending on distance and focal length (in a zoom) so a compromise setting may still be needed. It could be easy for an inexperienced photographer to get this wrong.
Best regards, John

Helpful

Frogfish

Link Posted 27/05/2011 - 21:32
Having recently bought the Sigma 30/1.4 I am amazed at some of the mixed reviews it has received in some quarters. Seems to be a lense you either love or hate ... I love it !

Stupidly sharp, excellent fast & quiet AF, lovely bokeh, very bright (on a recent test I did against the Voightlander Ultron 50/1.8 and 43/1.9 Ltd the Sigma was clearly much brighter at any given stop .... maybe half a stop extra light.

This is now one of 3 lenses that go everywhere with me (inc. Work & Shopping) .... along with the 43 Ltd and Sigma 50-150. You're going to love it, congrats !
http://frogfish.smugmug.com/ Pentax. Pentax DA*300/4, Cosina 55/1.2, Lens Baby Composer Pro & Edge 80, AFA x1.7, Metz 50 af1.
Nikon. D800. D600. Sigma 500/4.5, Nikon 300/2.8 VRII, Sigma 120-300/2.8, Zeiss Distagon ZF2 21/2.8, Zeiss Distagon ZF2 35/2.0, Sigma 50/1.4, Nikkor 85/1.8, Nikon TC20EIII, Nikon TC14EII, Kenko x1.4, Sigma 2.0

sorted78

Link Posted 29/05/2011 - 00:27
Quote:
Seems to be a lense you either love or hate ... I love it !

+1

I have one and have been very impressed with it.

While I'm sure that there have been some quality control issues, I'd concur with John's view that at least some of the negative reviews are down to user error/unrealistc expectations.

I think that in most practical situations where I've shot, the autofocus system is a bit of an imprecise instrument to consistently nail focus with such a small DOF. For the pictures where I've missed focus, it is usually either because I've moved slightly, or there wasn't an AF point exactly where I needed one.

If you get one, enjoy it, as others have said, it's a cracking lens and doesn't often leave my camera.

Helpful

Smeggypants

Link Posted 29/05/2011 - 01:22
johnriley wrote:

Manual focus: I can't agree that f1.4 lenses are difficult to focus, that one's a complete mystery to me. The limited DOF means that the sharp point snaps in and out beautifully and alo the brighter image makes it easier as well. When you stop down to f8 or whatever, all that's happened is that the focusing has been as accurate as it possibly can be. I think the problem is more that at f1.4 the point of focus is very precise and if the camera wavers to and fro or the subject moves focus will be instantly lost.

It's not that 1.4 lenses are difficult to focus it's that at apertures like 1.4 the viewfinder can't show a DOF that narrow, so you can be out of focus even though it looks in focus through the viewfinder.

I showed this effect to a shooting buddy recently with my Pentax A 50/1.2. I got him to look at and focus on a subject @ f/1.2 and asked him note teh DOF in the viewfinder and then note the DOF in the actual picture taken in the preview screen. he was actually shocked at the difference.

This is why I use Liveview through the sensor to accurately focus when I use my 1.2 and 1.4 lenses wide open, as through the sensor the correct DOF is displayed.

Focusing a 1.4 lens when the aperture is set to F8 wouldn't be a problem as the DOF would be larger than the minimum DOF resolution of the viewfinder.



Quote:

Calibrating AF: So far, no need found. Lenses snap visually into correct focus, even close up. Having the option is excellent, although i would have a slight concern that the correct point of focus may vary depending on distance and focal length (in a zoom) so a compromise setting may still be needed. It could be easy for an inexperienced photographer to get this wrong.

Then you've probably been lucky. that's cool.

I've just found my bit of paper with my AF adjustments scribbled down for my 2 K-5s


Sigma 30/1.4 K-5 one = +5 - K-5 two 0

Pentax FA 50/1.4 K-5 one = -10 - K-5 two -7

Pentax DA 14/2.8 K-5 one = 0 - K-5 two +2

Pentax DA* 50-135 K-5 one = -3 - K-5 two -3

Sigma 135-400 K-5 one = +5 - K-5 two +9

My DA 10-17 and Sigma 17-70 required no adjustment on either K-5, but both of them required adjustment on my K20D and K10D


Note: because the K-5 doesn't recognise the difference between the Sigma 30/1.4 and 135-400 I make sure I only use each lens on the respective K-5 I have calibrated it for. Not a problem
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283

Smeggypants

Link Posted 29/05/2011 - 01:27
Frogfish wrote:
Having recently bought the Sigma 30/1.4 I am amazed at some of the mixed reviews it has received in some quarters. Seems to be a lense you either love or hate ... I love it !

Stupidly sharp, excellent fast & quiet AF, lovely bokeh, very bright (on a recent test I did against the Voightlander Ultron 50/1.8 and 43/1.9 Ltd the Sigma was clearly much brighter at any given stop .... maybe half a stop extra light.

This is now one of 3 lenses that go everywhere with me (inc. Work & Shopping) .... along with the 43 Ltd and Sigma 50-150. You're going to love it, congrats !

I don't take mine out on every shoot as I like to take my A50/1.2 or FA50/1.4 out for a change too.

However I agree with pretty much every word you say. It's a fantastic lens.

I decided to buy one after I saw a few snaps taken with it. I got mine off ebay for 255 2nd hand, but it might as well have been new. Pristine, boxed with case et al.

I took it out with me today on a shoot of the Modified nationals custom car show, which is basically hoodies, glamour girls and custom cars. it was great for shooting narrow DOF shots of bits of cars
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283

Helpful

johnriley

Link Posted 29/05/2011 - 10:56
Quote:
It's not that 1.4 lenses are difficult to focus it's that at apertures like 1.4 the viewfinder can't show a DOF that narrow, so you can be out of focus even though it looks in focus through the viewfinder.

I showed this effect to a shooting buddy recently with my Pentax A 50/1.2. I got him to look at and focus on a subject @ f/1.2 and asked him note teh DOF in the viewfinder and then note the DOF in the actual picture taken in the preview screen. he was actually shocked at the difference.


We're talking about two different things. In any event it's impossible IMHO to judge DOF from the viewfinder, or from the back screen either, because they are both too small. Turn it into an A3 print and we're in a different ball game.

This is why if I'm going for maximum DOF I use the, say, f8 markers on a lens but actually set the lens to f11. This of course assumes that the lens does actually have DOF indicator markings. Most manual focus ones do. Most zooms do not.
Best regards, John

Algernon

Link Posted 29/05/2011 - 11:32
The cheaper Canons inc. the 60D link don't have any micro AF adjustment and I've just read in a magazine that they were quoted by Canon 72 to adjust the body to a lens plus 36 to adjust each lens.

What I find amazing is that several magazines have tested this camera and not even mentioned AF adjustment and are recommending it for semo-pro use. Obviously they mustn't have checked if the lens needed AF adjustment before doing the tests or they are keeping quiet about it or Canon adjusted the camera before submitting it for review

Imaging-Resourse picked it up link
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
Last Edited by Algernon on 29/05/2011 - 11:34

johnriley

Link Posted 29/05/2011 - 11:47
Quote:
Obviously they mustn't have checked if the lens needed AF adjustment before doing the tests

That's an interesting point - should the reviewer have to fine tune something sent from a manufacturer or is his/her job to test what has been sent, as-is?
Best regards, John

flossie

Link Posted 29/05/2011 - 11:54
vincechu wrote:
Thanks steve, I completely know what you're saying. I've never had a bad copy of a lens too. looking at some out of focus shots with the Sigma 30mm 1.4, it looks like a lot of it is user error, some people have done focus and recompose, which doesn't work well with the thin dof that 1.4 gives.

Though real bad copies are rare, I guess I kind of want some kind of reassurances, just in case.

An image can tell a thousand words...



Still shooting in the dark (literally and metaphorically)...

Algernon

Link Posted 29/05/2011 - 12:08
johnriley wrote:
Quote:
Obviously they mustn't have checked if the lens needed AF adjustment before doing the tests

That's an interesting point - should the reviewer have to fine tune something sent from a manufacturer or is his/her job to test what has been sent, as-is?

They should at least check it... should be part of their QA. Fleet St. send all new cameras/lenses for checking and adjustment before they use them. I think it's a standard charge of about 100.

I have a friend who has a Land Surveying business and the first thing they do with new Leica instruments costing up to 100,000 each is check them and either adjust them their selves or return them on the small percentage of instruments that don't pass QA.
Half Man... Half Pentax ... Half Cucumber

Pentax K-1 + K-5 and some other stuff

Algi
Last Edited by Algernon on 29/05/2011 - 12:12
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