Sigma 18-250mm DC OS HSM for Sony & Pentax

[stevecim]

up on dpreview,

Sigma's words are:
This lens incorporates a Hybrid Optical Stabilisation system which allows photographers to us the lens’ OS function even if the camera has a built in anti-shake system. If the photographer chooses to use the lens’ OS function, they must ensure that the camera’s built in stabiliser is switched off.

we be interesting to see which system works better Lens OS or Camera SSS

[David Kilpatrick]

I have the lens here now. Off to Venice for a few days, and it will go along - Shirley will use it. I have already tried it in Canon mount, and it's optically a step ahead of the Tamron/Sony design. The stabilisation is unusual, and parks the lens element vertically when inactive, so that if you view through the lens with OS turned on but 'asleep' the image is incorrectly composed - like a rising front. Then you touch the shutter release, the image immediately centres (always a vertical 'drop').

I actually got the sample sent to dPreview before they had it. I only had it for four days. I was not allowed to publish anything as dPreview had been promised first dibs. But I slipped a review comparing it with the Canon 18-200mm into f2 magazine June, and some pix on the lens into my Canon 500D reviews.

I plan to do some studio pix of the lens before using it, or I would have done tests yesterday. It is much larger than the Sony.

David

[dkloi]

The stabilisation is unusual, and parks the lens element vertically when inactive, so that if you view through the lens with OS turned on but 'asleep' the image is incorrectly composed - like a rising front. Then you touch the shutter release, the image immediately centres (always a vertical 'drop').
David

That figures. The decentering element is probably parked towards the bottom of the lens barrel, hence the front of the lens is above it so that the effective view is above the lens axis. Does the parked image follow the direction of gravity, i.e. when in portrait mode is the displacement of the image in the direction of the short or long side of the image? And if you switch of OS, does it park itself centered or decentered?

Cheers,
Daniel.

[David Kilpatrick]

It always parks towards the prism top physically, no matter how the lens is held. If OS is turned off, it parks centered. It only parks with a displaced image when OS is switched on, but inactive. Because of this, I have not been able to take a picture with the element displaced in its 'rising front' position (which would be rather cool, if you could force it to stay in that position). The effect is like a rising front with maybe a 3mm shift. I should be able to put the lens on my A900 with grid screen and measure this more accurately.

David

[mikeriach]

For an idiot like me, how does it work if you switch off the OS?
Or can't you....

A serious challenge to the Sony/Tamron 18-250?
I'm well pleased with mine compared to the 18-70 and Sigma 18-125.
The wife is keen to kidnap it but I'm resisting.

Mike

[David Kilpatrick]

If you switch off the OS the lens is centered. I will be shooting some comparison test with the Sony 18-250 and the Sigma 18-250 shortly.

David

[bossel]

Off to Venice for a few days, and it will go along...

We went to Venice 6 weeks ago and the Sony 18-250 was on the camera all day. Just not enough time to change lenses (also brought the 10-20mm and 50/1.7) but we brought back many nice memories.

Venice was already overrun by tourists (but you know that before) beginning of May and I guess now it will be worse and much hotter. Despite that, I still unconditionnally recommended it for a visit!

Btw this remembers me the wedding we saw -actually later, when there was a second bride and then a third, fourth etc we saw it wasn't one. It was some models hired by a photo club. We then noticed there were twenty or so photographers, taking the shoots and the meeting point was the place in front of the bar where we had just sat down for a beer. There was at least 100K Euro equipment walking in front of us...

Tip: If you have never been there before (like us) study very well the location of your hotel. Many of them are hard to find. At one point we were completely lost and a very friendly american couple helped us to find ours - my thanks to them, even if it's unlikely they read this forum. And if you're tired from walking all day, take Vaporetto line 2 for a trip around the island - gives you some nice occasions to shot some parts of Venice from a distance.

[David Kilpatrick]

The wedding was probably a professional seminar organised by Yervant Zanazanian in conjunction with Graphistudio. He does this in Venice once every year. He is an Armenian photographer whose father was court photographer to Haile Selassie in Ethiopia, where he grew up. He emigrated to Australia and is one of the world's most successful wedding professionals. He studied in Venice, and loves the city, and Graphistudio (one of his main trade partners) are based not far away.

David

[bakubo]

Here's a new review posted yesterday:

http://www.slrgear.com/reviews/showprod ... 242/cat/31

Here is what they said about the Sony 18-250mm compared to the Sigma 18-250mm:

"Slightly sharper, but not by much; CA is comparable. Corner shading and distortion are much worse."

[bakubo]

The Sigma is much bigger and heavier than the Tamron/Sony. For travel and walkaround this is a consideration.

Sigma:

Filter size: 72 mm
Dimensions: 79 x 101 mm
Weight: 630 grams

Tamron/Sony:

Filter size: 62mm
Dimensions: 74.4 x 84.3 mm
Weight: 430 grams

[David Kilpatrick]

The Sigma is not going to Venice. It's neither better nor worse than the Sony - it is rather better at close range at 250mm maybe, but has worse CA on many shots. The OS does not work as well as SSS - I've done some tests, enough to show me that in typical bad situations SSS is returning much sharper pix. So SSS would be used in preference on the A700. It's heavy, and the zoom direction is 'wrong' which really confuses both me and Shirley, we are used to the Sony zoom direction.

If the size for cabin baggage was bigger, it would go on my A350, but I just can't fit four DSLRs (A900, A700 and Nikon D5000 are going). Also, the Sigma 70-200mm f/2.8 is not going. I regret this, but it is too tall for the 25cm maximum thickness of bag allowed, and stowed the other way it takes up space needed for the rest of the kit.

Sigma - probably great for anyone needing OS. Not really needed for Sony at all. I've got some nice results though and it seems to be a good lens of its type.

David

[bakubo]

David, thanks for the new info. I like the smaller size and weight of the Sony so that makes the Sigma less interesting to me, even with HSM, but it is good to know that the Sony is generally about as good or better. The Sigma would be more interesting on a Canon or Nikon body though. Have you had a chance to use the new Tamron 18-270mm VC? How does it compare?

By the way, the Sony/Tamron 18-250mm is a pretty amazing package since it is so much smaller than the competition. Helps a lot with your packing and also just carrying it around all day.

[David Kilpatrick]

Yeah, the Canon 18-200mm IS is even bigger than the Sigma - but it's a very good lens, f/5.6 at the long end and optically a notch up from any of the f/6.3 variants. I like the results from the Sigma but packing camera gear for this short trip has been a real problem. Each camera has its own advantages, each lens the same. I have decided to take the 28-75mm instead of the 28-105mm and I know I will regret it despite the gain in sharpness and speed. The 100-150mm range on full frame is important in Venice and most Italian old cities because of the narrow streets - long shots work best. But I don't really want the 70-300mm G on the camera all the time.

So, I've put the 2X Teleplus DG7 in the kit to use with the 28-75mm. I have tested this, and it works well - 56-150mm f/5.6, quite a usable specification.

Overall kit: 16mm Sigma fisheye, 12-24mm Sigma, 28-75mm KM, 70-300mm SSM, 2X Teleplus, A900; 18-250mm Sony on A700; 18-55mm Nikon on D5000; Sanyo XActi HD video cam 720p; Asus EeePC; 250GB Iomega portable USB-powered HD; card reader. Gitzo Traveller 6X carbonfibre tripod. No flash. Kipling backpack carry-on camera bag with wheels and extending handle. Soft Tenba bags in the suitcase. Chargers and spare batts. About 64GB of cards.

I may put the 100mm SF in as well in case there are misty days.

In SE Scotland this evening (6pm) it was 26 celsius, the weather changed between noon and evening to become MUCH warmer - almost uncomfortable. Venice could be in the 30s. I'm not even bothering to take a coat.

David

[bakubo]

In SE Scotland this evening (6pm) it was 26 celsius, the weather changed between noon and evening to become MUCH warmer - almost uncomfortable. Venice could be in the 30s. I'm not even bothering to take a coat.

Venice can be hot. Hard to imagine that at this time of year you would ever have any need for a coat there. In April 2001 these guys don't look hot, but I was there in June 1994 also and it was fairly hot:

[David Kilpatrick]

Venice about 10F-5C lower than Scotland in temp - very comfortable, cloudy, light rain, still OK for sitting outside at night to eat. Prices ridiculous, even without the Euro-Pound exchange shifts of the last year. Aiports, you are looking at a $10 beer -restaurant tonight in a mainland suburb well out of Venice centre, $70 for a couple of beers each, one simple course (very simple) and coffee.

Still, we got the bus to the hotel, 6 euros for two instead a taxi at 30 euros. Shirley has not used a bus in Britain for 45 years and was not happy with the idea. But of course, it was a coach with luggage compartments, air con, not like a British bus (which would have been twice the price, no luggage space at all, anti-drug use blue lighting and seats from 1965). So she's happy that we use buses and trains now I think (I had no doubts that the Italian public transport would be a different order from UK).

David