A Question about filter

[dynaxfl]

This is my first post here I just bought a900 body last month and i already have a bunch of Minolta G lens (17-35G, 85mmG, 80-200G). I had a 28-70G but I gave it to my dad since he just started his interests in photography, so I bought the new CZ 24-70. I do notice that the old G lens in general are very good with a900 but they are not very good with flares and ghosting, especially the 17-35G. My question is that if I use the Sony protective filter that claimed to have CZ T* coating on my old lens, will that help to reduce the flare and ghosting?

I really enjoy reading the forum here, learned a lot here.

[David Kilpatrick]

No, adding a filter however well coated can never reduce flare or ghosting. The 17-35mm G is prone to hot spot sensor reflection flare, and this can not be removed. The 85mm and 80-200mm should be fine, with the correct lens hoods, and are not known for sensor reflection ghosting. All a multicoated filter can do is avoid the extra flare produced by a single coated or uncoated filter - all filters, including T* coated Sony ones, will introduce more flare (imperceptible with T* one hopes). I would certainl use a T* filter on the 24-70mm, protect such a valuable lens from the start. With a T* coated lens and filter, you should see no significant flare. You will see some, I've managed to produce small flare spots into the sun from the 24-70, but that can be done with almost any lens no matter how well coated.

David

[dynaxfl]

Thank you, David, that's an awesome quick reply! I already bought the Sony T* coated filter for my CZ 24-70mm lens. For the curiosity, I used this filter on my 17-35G, and i didn't see any difference it makes than the old Hoya ultra thin filter. So thank you to confirm on this! But what I did find, was that the best aperture setting for 17-35G on 17mm end should between F5.6 & F11. Wider than F5.6 it has serious purple fringing and smaller than F8, the ghost start to appear.

[Dr. Harout]

Hi Dynaxfl and welcome to the forum.
Personally I stopped using any filters mounted permanently on a lens. This is my opinion of course and I might be quite subjective but I found out it degrades the quality of a lens, and in the first instance the sharpness. You do understand that I'm referring to UV or Skylight filters.
Polarizing filters are different. ND or graduals are sometimes indispensable.

[dynaxfl]

Hi Dr. Harout, you are not the only one not to use the UV filter. I once met a photographer who works for Nikon on the flight to LA. He showed me about D1 when the DSLR was still rare at the time. He basically told me the same story as yours. But for me, I think UV filter is important just for the protection purpose. I went to the Red Canyon in 2004 and the hill was so slippery and I fall at least three times with a9 was on my neck. The lens (28-70G)got hit too, but thankfully I had a UV filter attached, so the lens was not hurt After that experience, the UV filter stays on the lens 100%. Interestingly SONY doesn't call UV filter but protective filter.

[GaryMulcahey]

I totally agree with the Doc.
You spend sometimes thousands on a lens and then put a ¢10 piece of glass in front of it to protect it. Never made much sense to me. Sometimes filters are a necessity but more so in the film days.
But that is just my ¢10.
Protect your lenses with lens caps.

G

[dynaxfl]

Who said my or other's filter is ¢10? I think there is a difference between good and bad filter ... perhaps someone can do some test to prove the theories Actually I did a quick test on 17-35mmG on 17mm end, with and w/o filter. My finding was no difference.

[GaryMulcahey]

LOL! I know you didn't pay that little for a filter. I was just trying to make a point.
There are good quality filters but they don't come close to the quality of expensive lenses.
Light has to pass through cheaper, lesser quality glass to get to your very crisp, well made, expensive glass.
Optically correct glass made by the good people at Zeiss deserves better than putting cheap(by comparison) UV filters in front of them.

Now I'm just ranting. But you know where I stand on the filter issue.


G

[dynaxfl]

Hi G, I know i know... but seriously, I did my quick test... was originally to see if the Sony T* coating filter is better than Hoya Ultra thin filter (both them cost over $100 each), and I didn't see the difference. I basically shot three sets of photos, with Sony filter, with Hoya filter and without filter. I did open every picture to 100% to check and i found no difference.

I think even with the lens cap, it's still very easy to accidently to touch the lens surface with your finger, and get finger prints on your lens, you'll have to wipe it off, and from what i heard, to clean the lens surface too often would also hurt the lens (damage the coating).

So this is my rant

[Dr. Harout]

Hi G, I know i know... but seriously, I did my quick test... was originally to see if the Sony T* coating filter is better than Hoya Ultra thin filter (both them cost over $100 each), and I didn't see the difference. I basically shot three sets of photos, with Sony filter, with Hoya filter and without filter. I did open every picture to 100% to check and i found no difference.

I think even with the lens cap, it's still very easy to accidently to touch the lens surface with your finger, and get finger prints on your lens, you'll have to wipe it off, and from what i heard, to clean the lens surface too often would also hurt the lens (damage the coating).

So this is my rant

Always carry a Lens-Pen with you.

[GaryMulcahey]

Dynaxfl,
This is what makes us all unique and interesting. We do what we do differently with diverse results.
Sometime I'm a little old school in my way of doing things. <<<That just sounded old >>>
From a non UV filter user to a UV filter user, Happy New Year.


G

[InTheSky]

Again sorry for all the pixel peeper test i have done one my lens in the past but i can tell you that there is only a few filter on the market that will not affect the resolution of your lens.

On my first experience on slr camera, i was doing some test on lens by leaving the filter in place, and discover only after that how a filter can damage the image quality.

Example, on a 200-400mm 5.6 of Tamron, i was able to see huge difference between a UV Hoya standard filter and Hoya Super HMC. The Tiffen was more bad than the Hoya Standard. Even the Histogram on my camera was changing between UV on and OFF. The only filter that make almost not difference was the Hoya Super HMC.

When i got my old Tamron 300mm 2.8 adaptall, i was affraid to scratch the front lens when i take picture in the hood and decide to buy a cheap 112mm filter on ebay for 25 $. the result, even with this Huge front element of the 300mm (surface...), the Cheap UV filter took about enought resolution that shooting with a 200mm has no difference in the cropping image. I was lucky after that to get a 112mm B&W filter for 35$ ! on Ebay. Again test with the B&W showed me that there is no perceptible difference with or without the filter.

I have filter in front of all my lenses, because i don't like to bring lens caps and I'm always switching from one lens to another. And i like (yes this is not correct ...) to clean my lens with my clothes. In certain place you don't have time to search for you special tissue to clean your lens (under rain, under mod picture, etc.).

When you buy a Digital camera, you have to estimate a budget on the Battery and the memory card. I think this is the same law for lenses, if you are buying a lens you have to Always think of % of the price in Filter. Higher the price of the lens is, higher the price is to protect it. But in my mind, the filter should be part of the price in your head.

I'm sure Ferrari owners do not put Wall Mart tires on there car . (but yes ... the car can go to point A to B with cheap tire ... but at what cost )

Regards,

Frank

[dynaxfl]

Hi Frank, thanks for the information. I think the keywords here are GOOD FILTER. All of my filters are Hoya Super HMC and they were not cheap. Now with getting CZ lens, the SONY UV filter is even more expensive. But I guess it's a good investment since the lens is so costly.