[charliezap]

For months I was looking at the Sigma (Bigma) 50-500mm lens but what has impressed me lately is the quality of the photos being posted with the Pentax 55-300 lens.The sharpness--contrast--color rendition-- really looks very good for a lens costing around $350 as compared to the other at $1600.My lenses that I now use on my K20d are the 18-250 Pentax and my Quantaray 70-300mm which doesn't do a half bad job but the 55-300 has me rethinking the purchase of the Bigma.I need some gentle nudges in the right direction.-Thanks---CharlieZap

[Pentaxor]

for what purpose would you want the Bigma?

do you really need the 400-500mm focal length? are you willing to carry such a long and heavy lens? if your answer is Yes, then go for the Bigma.

if you don't need those focal lengths and happy with what the 55-300 can offer, it is enough and could save you a lot of monies. I would keep the remaining budget for something else like another lens or body.

[yyyzzz]

Got the Pentax DA 55-300 recently. Do not have the bigma. But I agree with the assessment on Photozone. It does not have the highest resolution at the 300mm. In fact, you perhaps can crop the photo at the 250mm or 270mm to get the 300mm. On the other hand, it produces contrasty photos, a characteristics for a typical Pentax lens. It is very portable and much lighter than the Bigma.

The two lenses are in two very different categories. It is hard to make proper comparisons. But if I had the budget AND the need, I would get the DA* 60-250mm instead of the Bigma. You can crop the image since it has such a high resolution at the 250mm side. In addition, you must have a tripod to use the 500mm end. You can handhold the DA*, I guess.

An alternative is to get a Tamron 500mm SP mirror. Together with the DA, the package is still lighter than the Bigma. The package would work if you do not shoot 500mm that often and you can tolerate manual focusing.

[paddy567]

I just got back from 3 weeks in Namibia with the 55-300. I don't know what your standards are, but with photos like this, I have no complaints!

[kytra]

I just got back from 3 weeks in Namibia with the 55-300. I don't know what your standards are, but with photos like this, I have no complaints!

nice pics, good IQ.

Imagine you'd have had 200mm bigger FL - that gazelle would have filled that frame

[daviex1]

very good pics love em

[Rondec]

There is a huge difference in size. The DA 55-300 is pretty sharp in the f8-11 range, although it certainly won't beat upper end lenses like the DA 300 or DA 60-250. Still, I drop it in my bag without too much thought, just because it isn't very big and is quite light, where (if I had any of those upper end lenses) I would think twice about taking a bigger lens a long.

[DaveInPA]

I bought the DA 55-300 back in January and love it. Its light and does the job.

[GaryH]

I own the 18-250, Bigma and 55-300 and bought them in that order. I will offer these thoughts.
The Bigma is decently sharp but requires a monopod in most situations when shooting at 500mm.
It does for me at least. Its heavy and can be clumsy to haul around but I generally use it specifically for wildlife and keep it attached to my K20.
The 55-300 I bought last because I wanted some reach and better image quality than the 18-250 had to offer in a lighter package for travel . I keep it in a bag with my 16-50 and use them for traveling light . The 55-300 takes very nice and sharp photos and I feel good about the purchase of it. I find it easier to get BIF pics with it than I do with the Bigma.
In my opinion, the two lenses have very different uses and I use them with my outing and equipment needs in mind. It would always be great to have 500mm at your disposal but you have to remember how much different the outing would be while hauling it around.
So far the KX/55-300 combo is great for times when I want to travel light.

I have kept the 18-250 to use solely for vacations or travel when photography is not the main goal but I would like to be able to come back with some decent pictures.

Overall the 55-300 is a decent lens that can do many of the things the Bigma can up to 300mm....

[SpecialK]

If you really want the longer range, the 150-500 may be an option for you. It is (only) $1,000. I got it instead of the 50-500 because I'm pretty well covered for shorter ranges.

[charliezap]

Thanks to everyone for the input to date.My home borders conservation land on two sides and from my deck the Bigma would be great but it looks like the 55-300 lens would get more of a daily use away from the home front and the money that I would save I would probably invest in a decent macro lens.--charliezap

[yyyzzz]

Do not forget a 500mm mirror lens.

[charliezap]

Do not forget a 500mm mirror lens.

I had a mirror lens lens awhile ago for my 35mm slr and I really didn't like the IQ that it produced.How are they nowadays for digital dslrs?---charliezap

[KjetilH]

Doubt the lenses got any better, but you could at least compensate for the lack of contrast in post processing or by using in-camera JPEG settings. Probably easier to handhold due to SR and some added weight from the DSLR itself.

Edit: And the ability to adjust ISO is, naturally, very useful.

[MrCynical]

One thing to note about this lens is that for a consumer zoom its bokeh (see shots above) is absolutely beautiful!