[JMitchell]

Hi guys,
As some of you might know, I am on my quest to decide whether to buy the Sigma 70-300mm of the Tamron of the same focal lenth.
I was checking out this guy's gallery, and there are some great shots, but many of them seem to have this effect where they have a sort of 'square' bokeh / DOF blurring. Is this bad image quality (from the upload), or the lens?
DSC_0167.jpg photo - Paolo Vairo photos at pbase.com
That is the image that most clearly explains it.


Thanks,

(Also if anyone wants to say which of those two lenses is better please tell me, but I would like a reason. I am leaning Sigma's way, but the Tamron looks nicer....which is a consideration dammit! )

[Dave]

I would say it's a mixture of High ISO that is giving some grain & then sharpening afterwards in Photoshop that is accectauting the grain further in the bokeh

[Feb14]

Are you sure it isn't just noise? Perhaps from high ISO and heavy cropping. I would not think it was the lens itself.
There is no EXIF in the image to tell what the camera settings were.

[stepheno]

Well, it looks like good old fashioned noise. However I d/l the image ran it through Noiseware and it came out tons better but on magnification the squares are still there. I get the feeling that the guy has done quite a bit of processing including sharpening and he's got pixelation. I may be way of beam here but I don't think the lens would cause that. With regard to the two lenses in question I wouldn't like to recommend either. HTH.

[Steve]

Its simply a case of noise and pixelation. The file size of the image imediately confirms it for me. If you are trying to judge the differences between the two lenses than you need much higher defination and more detailed shots to compare otherwise your final decison will be made on ropy ground.

Unfortunately I can't provide better quality images from either to help

[JMitchell]

Originally Posted by Steve

Its simply a case of noise and pixelation. The file size of the image imediately confirms it for me. If you are trying to judge the differences between the two lenses than you need much higher defination and more detailed shots to compare otherwise your final decison will be made on ropy ground.

Unfortunately I can't provide better quality images from either to help

No I know, I was just wondering whether this was a bad effect caused by the lens being cheap, or not. I have some big images with which to make comparison, but even then you can never be sure.

[JMitchell]

Originally Posted by stepheno

With regard to the two lenses in question I wouldn't like to recommend either. HTH.

I know you wouldn't, but I think that is a rather snobbish view considering some people can't afford Nikkor 70-300VRs. I'm not expecting to win a world's best lens competition with either, I just want a beginner telephoto (as I am a beginner), that produces decent enough images for the level I am at.

[Dave]

For the money the Sigma is a very competent lens & like you say a great introduction to telephoto lenses. The image does get a bit soft towards the 300mm end of the zoom, but acceptable for the money. If you look at the "Street Photography" thread you'll see acouple of links to shots I took with the said lens (300mm shots)

If you want an even cheaper option then look at the Nikon 70-200mm lens ...can be had for under £80 from Hong Kong....... not the greatest quailty build , but it does the job

[JMitchell]

Originally Posted by Dave

For the money the Sigma is a very competent lens & like you say a great introduction to telephoto lenses. The image does get a bit soft towards the 300mm end of the zoom, but acceptable for the money.

If you want an even cheaper option then look at the Nikon 70-200mm lens ...can be had for under £80 from Hong Kong....... not the greatest quailty build , but it does the job

Thank you, yes I was thinking Sigma, but I am very annoyed that the Tamron's aesthetics are so much nicer, oh well.
With regards to the Nikon....I think I can afford to spend a little more (up to about £200), so perhaps I'll leave those

[Dave]

I think you are doing the right thing by sticking with a budget, as sometime you may find you don't use a certain focal range lens that often ...for example I rarely use my 70-200mm lens , vs the 17-55 or 10-20mm . Once you suss out which focal range lens is most importnat, you can then spend your money more wisely ....wish i took my own advice sometimes

[JMitchell]

Originally Posted by Dave

I think you are doing the right thing by sticking with a budget, as sometime you may find you don't use a certain focal range lens that often ...for example I rarely use my 70-200mm lens , vs the 17-55 or 10-20mm . Once you suss out which focal range lens is most importnat, you can then spend your money more wisely ....wish i took my own advice sometimes

True. I am quite worried that my preffered focal length is going to be quite large, and therefore cost me quite a bit more...but I'll cross that bridge in about 20 years I imagine

[Les Meehan]

I think Dave has touched on a very important point re buying lenses. Before you commit to the next lens REALLY consider the type of images you like best. If necessary trawl a few galleries and do a personal survey of the images you REALLY like and then check out which focal length was used. This will give you a clue as to where your personal vision is in relation to focal length (of course I am aware that your vision will probably change over time). With this knowledge you will be better placed to decide.

If you don't see yourself using the really long focal lengths that often, why not consider a 'prime' lens of around 200mm? That way you will get superior quality, which seems to be important to you from your posts, and not waste money on unused focal lengths and poor quality. Of course, zooms are convenient but often that boils down to laziness (not implying you are by any means, OK).
On the aesthetics aspect of the lens you could always paint it yellow or green just for fun.