Sigma 70-300 vs Pentax 55-300 vs Pentax 50-200

[ed.ginsberg]

I do stock photography and have heard mixed reviews about the Sigma 70-300, in particular that it becomes too soft above 200mm.  Is this true?  What about fringing?

I am weighing purchasing a used Sigma.

But my question concerns the Marco aspect.  How soft is the macro?  Does adding a converter affect the image quality?



Thank you for your help.

[pihe]

Sigma zoom lenses (and a few primes) always had problems with quality control. I strongly recommend to try the lens for a longer time before you buy it. Take a laptop with you and see the test shots from pixel to pixel. The Sigma's macro is rather close-up than real macro but it's undeniably better than having no macro function at all, like the DA 55-300.

[vk4akp]

I'd like a Pentax DA 55-300 but the current prices in Australia are just pure fantasy unfortunately.

In the mean time I've had to settle for a Pentax DA 50-200. I'm sure it's not going to have enough reach but I guess I'll just have to put up with this for a while.

So for now I've ordered the 50-200. It should turn up by the end of the week all going well.

If anyone see's any extremely good deals going on the 55-300 please keep me in mind.

The Sigma 70-300 is very good value for money at AUD$299 and the macro feature between 200-300 is very handy for long range close up shots of birds etc.

However I have decided to go Pentax all the way with my lens's. As painful as it will be on the wallet I just can't ignore the benefits.

- Sigma lens owners report that they tend to creep.
- The end of the Sigma lens rotates as it zooms. This can be a problem for some filters.
- You can not touch up the focus manually in automatic mode on the Sigma lens like you can with the Pentax.
- The Sigma lens takes different sized filters.
- The sigma lens is heaver and longer.

.-.-.

[Mike Pearson]

vk4akp,

My daughter now has my Sigma 70-300 APO Macro and loves it - I had no problems with it and it was a very solid performer. I moved on to the Pentax for some of the reasons you quoted as well as what I think is better image quality - but that of course is subjective.

I also have the Pentax 50-200 which still gets used quite often.

Mike

[calsan]

Hi Ed,

I have the Sigma 70 -300.
Like all lenses, it's sharpest stopped down by two stops.
Therefore, because it's widest aperture is 5.6 at 300mm, to be sharp at 300mm means using F11.  At F11, it's great.

However:
The question then is not is the lens sharp enough, but is a cheap zoom lens bright or fast enough for what I want?  It's certainly good enough for day time, however, morning and dusk is a complete waste of time with any of these lenses.

A tele converter will make it even slower.  You really need to start out with an F2.8 lens to be able to get away with one.

The macro is 1:2 and certainly OK.  But difficult to hand hold, for the above reasons to do with F stop and also because it's only between 200 and 300mm, so it's hard to avoid wobble if the light's no good.

Basically, it's a good lens for the money, but it's not professional grade.  If you want any better, it will cost at least 4 times more.  If you're actually getting paid for your work, as 'stock photography' implies, I doubt that any of these lenses would be good enough!  Anyway, note that there is an APO version of the Sigma 70-300 and one without the APO designation.  Don't get one unless it's got APO written on it.

[calsan]

Reviving a sleeping thread...

OK.  Here's a typical example of a subject likely to cause fringing problems due to high contrast subject.
Shot with K10D and Sigma 70-300 APO. 
Views of this egret cropped at 100% for pixel peeping pleasure.

First image with beak down is at F5.6 and 300mm (ie wide open)
Second image with beak horizontal (I stopped down to recover highlights) is at F8 and 300mm.
Both at ISO 100, zero corrections made in processing.

As you can see, there's some improvement made by using F8, but not around the high contrast edges and mostly due to recovering detail in the plumage.

I'd love to have a 300/4 with SDM, because there's not much I can do to get BIF shots with this lens, focusing is too slow and alarmingly noisy.

Would like to see a similar example with the 55-300 Pentax ... anyone?