Sony 70-300mm G VS Sony 75-300mm

[sony_photographer_jake]

I have been using the Sony 75-300mm lens for a while now.
When using it on high contrast backgrounds or in bright daylight it suffers terribly from purple fringing and it completely wrecks my photos. Is there any way I can reduce the purple fringing, as I have a UV filter which doesn't seem to reduce the fringing.
Would I be better off going for the Sony 70-300mm G lens.

Has anyone on the forums got / used one of these lenses, and what recommendations they could make to me would be most helpful.

[ianpinion]

Hi Jake,

The purple fringing you're experiencing, whilst using this lens in high contrast conditions, is a common problem we all have suffered with. It's known as chromatic aberations and effects many of the cheaper, standard quality lenses when shooting in either very bright conditions or where you have a high contrast between your foreground and background. The reason is that these cheaper lenses are made to a price and to meet these keener prices the manufacturers reduce the number of glass elements within the lens, in particular the really dense glass elements that help to control how the light behaves as it passes through the barrel of the lens.

Therefore, if you buy a better quality lens, you'll find that firstly it's significantly heavier because of the extra glass within it, the build quality is much improved and the quality of the optics within the lens are much more refined too. The result of all these improvements ensures you should suffer less with chromatic aberations, barrel distortions etc. that can seriously spoil your images. So by buying a G Series lens will mean that you should be able to get much better results when shooting in these condtions. However, the first rule you should remember is that as a photographer you are writing with light and if the quality of light isn't right for you to create the image you want then don't take the shot. Instead, wait until the light conditions are right until you take the shot and then you will get the result you want and not one you're dissappointed with.

[sony_photographer_jake]

Thanks for your explanation. I understand what all this is about now. I have decided to start having a look at the 70-300mm G properley. I have got a little bit of saving to do now!

[ianpinion]

I should have mentioned that chromatic aberations are caused by the light refracting through the lens.

[chris-p]

Originally Posted by ianpinion

I should have mentioned that chromatic aberations are caused by the light refracting through the lens.

Actually it's dispersion, not refraction.

I am such a nerd...

Anyway, you can attempt to remove a lot of CA in post processing. If you use any verison of Photoshop (Elements, CS etc.) and shoot in RAw, the CA tab in ACR does a pretty good job.

Also, your UV filter won't help - that's not what they're for. Digital sensors aren't very sensitive to UV light like film is so the main purpose of UV filters on digital are to protect the lens. However they're normally flat bits of glass so you can get flare and other issues with them. I still use them, it's much cheaper to replace a filter than a front element...

[sony_photographer_jake]

Is it best to get a high quality UV and CPL filter for use on this lens. Or shall I just get a cheap UV filter.

[chris-p]

Originally Posted by sony_photographer_jake

Is it best to get a high quality UV and CPL filter for use on this lens. Or shall I just get a cheap UV filter.

Tough one. You'll set off a debate with that one.

Circular polarisers are worth spending a bit of money on. I've bought really cheap ones and they don't polarise, they just turn the shot a bit yellow or a bit blue. £10-£15 should sort you out with a good one. I'm not sure how much use it'll get on a long lens though - I've never put one on my 70-300mm

With UVs, I personally don't see the point. I know they can degrade image quality but I've never seen it, even using cheap ones. The only thing to watch out for is that you can get more flare and ghosting with UV filters and the cheaper they are the worse it can get. However if it's such a massive problem for a particular shot, you can always remove it from the lens.

I'd probably go for this UV and this polariser if you really want one. Personally I wouldn't bother with the polariser myself, given the size of the lens hood on the 75-300mm G lens you'll never get your fingers in to rotate it anyway...

[ianpinion]

I use a Hoya HD Protector filter with my best lenses and I've not noticed any harmful effects with using it. Might be another option to a UV or skylight filter.

[chris-p]

Originally Posted by ianpinion

I use a Hoya HD Protector filter with my best lenses and I've not noticed any harmful effects with using it. Might be another option to a UV or skylight filter.

They're supposed to be very good. I've not used them myself but they're coated and toughened and the general concensus seems to be that while they are relatively expensive, they are excellent protectors.

[sony_photographer_jake]

Sorry for late reply, not been on the forums for a little while.
Will take on board your advise, will buy myself a decent UV filter to protect the lens and will sort out a good CPL filter.

Thanks for your help.