Cropped DA*60-250 v. Sigma 150-500 results

A short while back in a discussion about long telephoto lenses I promised to compare cropped shots from the DA*60-250 against uncropped shots from the Sigma 150-500.

I managed to do a short test during the Pentax Day at Clifton Cameras on Dec 12th.

You will notice from my results that the cropped 60-250 shots have greater DOF due to the 250mm focal length as opposed to the 500mm focal length shots from the Sigma. This, the loss of 1.3 stops, plus it's considerable size and weight (I can fit my 60-250 into my shoulder bag, no way with the Sigma! :shock, was enough to prevent me from getting the Sigma as well as (IMO) the better colour and contrast from the DA*. It was also interesting to find that the Sigma's HSM AF system was no quicker than the SDM AF of the DA*60-250.

I know the Sigma is not as expensive as the DA*60-250 (now), but it just shows what an exceptional lens the DA*60-250 is. I must admit that the Sigma exceded my expectations, it is a nice lens, unfortunately the shop didn't have the Sigma 120-400 in Pentax mount for me to try. I hope to do some more comparisons at SRS when they hold their new store open day.

The only reason I can see to get the Sigma would be for shots that would require more than a 2x crop where the resolution drops below an acceptable level for A4 prints (3.6MP from a K20D/K-7 sensor), or for larger prints.

The DA*60-250 shot is a 1800 x 1200 crop from a 100% shot, the Sigma was resized to 1800 x 1200 to make a fair comparison (click on images for full size versions), both taken at f8.0, ISO 100, K20D on tripod with 2 sec (mirror up) delay.

Sigma at 500mm @ f8.0




DA*60-250 at 250mm @ f8.0

Looks like a no brainer...advantage to the Sigmiester

Regards

:: In what way?

Prefer the better colour saturation and contrast of the Sigma.

Regards

That depends on what has been done to each image in Photoshop. As regards crispness, the Pentax shot is significantly better. The contrast and saturation can be adjusted to anything we like.

I had to assume that processing would be same. I agree on the crispness but my first impression was that the Sig shot left a better visual impression.

Regards

The cropping wouldn't look so good for a darker and noisier image, would it?

Also I like the shallow DOF of the Sigma shot above.

The shots were not photoshopped in any way. They are straight from Silkypix DS Pro output with the same settings for contrast, saturation and sharpness

The Sigma over exposed compared to the DA* (1/8 sec compared to 1/25 sec, it's all in the images EXIF), I adjusted the exposure in Silkypix to give approximately the same histogram spread for each shot, but they do differ due to the difference in the colour and contrast of the two lenses, plus the different image content due to the different angular FOV. The Sigma shot has more initial impact due to the shallower DOF at 500mm compared to 250mm, but is significantly less sharp and has a more muted colour and contrast for the same settings. I agree that contrast and saturation can be adjusted in PP'ing, but I was not trying to do any significant PP adjustments.

For me, I find that the DOF at 250mm and around f5.6 is very shallow, and a shallower DOF, narrower angle of view and increased weight all adds up to make my birding photography even more difficult than it is!

The object of the excercise was to satisfy myself that having a longer, slower lens would not bring any major benefit to my telephoto shooting. With the British light at this time of year I need all the lens speed I can get, as I frequently shoot wide open at f4.0 at a low ISO and use a slower shutter speed than I could with a 500mm lens.

I am not decrying the Sigma in any way, I will say that the performance of the Sigma even wide open at 500mm was excellent, it was very little different than at f8. What continually amazes me however, is the performance of the DA*60-250, it's one heck of a versatile lens and even at the new higher prices can't be considered excessively expensive considering it's superb optical performance.

I do intend to do a similar comparison with the Sigma 120-400 HSM as that is an interesting tele-zoom lens and is not expensive either.

I must agree with John. The Pentax shot is much crisper and the colours seem to be more natural. Nothing wrong with the Sigie but use it for 500mm applications.

That's probably why I prefer my 50-500mm to the 60-250mm on long shots, I still use a K10D.

That made me laugh .. I was just imagining the posts after yours

Well, judge for yourself.

Here's a couple of shots I took about a month ago, both handheld at 250mm, cropped quite heavily from the originals shown, the EXIF is intact in the cropped shots (click on the cropped images for the 100%size).

A pair of Great Tits. - 1/160 at f5.0 ISO 200

Full shot (resized)




Cropped from above (click on image for 100%)




A Nuthatch - 1/160 sec at f5.0 ISO 200

Full shot (resized)




Cropped from above (click on image for 100%)

Good, but that's only ISO 200. By "noisier", I was thinking of ISO 800 and above.

I very rarely shoot at ISO 800 if I can help it as the IQ drops away badly, that's why I prefer a faster, very sharp lens. When I was shooting with my DA 55-300 I had to use f8.0 to get acceptable sharpness and that meant using ISO 800. With the 60-250 I get much better sharpness and micro contrast at f4.0 than the 55-300 at f8.0 (or even F11), so I can use that benefit to shoot at ISO 200.

If I was using the Sigma I would loose at least 1 stop, so that would mean ISO 400 if I used the same shutter speed, which would be pushing it handheld with that lens, even with SR I would probably have to shoot at 1/250 or higher which means another stop or more lost, so I'm back to square one, probably worse!

It's difficult enough to capture small birds with the 60-250 without handshake or blur due to their quick movements at lowish shutter speeds. I don't think that a slower longer lens would be of any help to me at all for the majority of my long lens shooting, what you may gain in one area you seem to loose out in another, sometimes much more than you'd expect. Certainly having the higher resolution of the K20D or K-7 helps when cropping, as they say "every little helps!"

Richard,

The cropped DA*60-250 shot looks a tad better to me than the Sigma, which is very impressive. Even if you think there is little or no difference it is impressive!

The bird shots also show the excellence of the DA*60-250!

Cheers,
Lance

So are we discussing the use of shorter Pentax telephoto lenses against third party longer glass, along with their IQ?

If so, here is a hand held shot on an IS body. 500mmAF Reflex.

link

Effective FOV would be the same as 750mm due to the 1.5x factor of the sensor.

I also have a 50-500 Bigma and find it heavy and sometimes hard to get the best from it, hence I bought the AF Reflex.

I will be using my 200 and 300 SMC's later today with the 1.7xAF and will post some results if they turn out to have a decent IQ.

Regards