Does a filter degrade the image? You decide!

Stewart, would love to see more of the same - other types of shots, in bright sunlight etc.

Gary.
 
Even with the answer I still cannot see any perceivable difference (y)
( please excuse my gramma she has not been well for sometime :D)
 
StewartR said:
Can you tell the difference?
Click to expand...

This is an old thread but I havn't read it before.

At this time of posting, I have not gone to the end to find the answer.

I think that "A" is without filter.

They sky is more saturated. There is more contrast in the foliage.

Andrew
 
gaffer said:
This is an old thread but I havn't read it before.

At this time of posting, I have not gone to the end to find the answer.

I think that "A" is without filter.

They sky is more saturated. There is more contrast in the foliage.

Andrew
Click to expand...

So now, having read the thread and found that I am wrong, I can only conclude:

I was expecting the filter to degrade the image. On the contrary, I believe that it enhances it. (in this case...)

Andrew
 
on 2A and 2B, you see more fringe defects on the 2B if you look at the high contrast edges... um... filter improves quality? interesting!!
 
It's worth pointing out that unless the testing environment is under full control then you've got other variables at play e.g. a darker leaf could be caused by the shadow of a bird overhead or a slight breeze altering the angle at which a leaf reflects the sun changing how bright and how saturated it looks.

I'm not taking any sides in the debate, but just saying that the differences that can be perceived may not be down to solely the addition of a filter.

I agree, it would be interesting to see a scene compared when you've got sunlight glistening off a reflective surface or other point sources of lights.
 
The sky at the top of the crop in 2A looks very slightly more grainy to me in comparison with 2B. Otherwise I can't notice any difference between the photos, maybe the As are fractionaly more saturated? :thinking:

I realised the old filters I was using did me no favours, bad flares with the cheap Hama filter on the Sigma lens, and after a quick test I was looking at least a stop, probably more with the filter on the 70-210. So on the basis of this test, I've bought Hoya Pro 1 Digital filters for all my lenses which arrived yesterday. As I shoot at rallies mostly, I'd rather chip a filter than the front element on a lens! ;)

Would be interesting to see some tests in difficult lighting or direct light, if I ever get the chance I might do a couple...
 
OK then - with more challenging lighting!

Marrakech, late at night with bright bulbs all over the place.

Spot the difference:

2472102068_99e8181ee3.jpg


http://www.flickr.com/photos/dvf-woz/2472102068/sizes/o/

2472103428_b6b37b4d62.jpg


http://www.flickr.com/photos/dvf-woz/2472103428/sizes/o/

;)

Excuse the slope - they were test shots taken after I noticed something fishy going on with my pictures that night.

Admittedly it's not a GREAT filter, but I decided to never use a protection filter again once I saw these two shots.
I'm really glad I noticed early in the night because I got some classic shots and they would have been ruined otherwise!
 
Well I have certainly learned something from this thread! (I use a UV on all my lenses) BUT, if ever I want to take a picture of a brick wall, I will take it off!
 
wontolla said:
Well I have certainly learned something from this thread! (I use a UV on all my lenses) BUT, if ever I want to take a picture of a brick wall, I will take it off!
Click to expand...

You can see my pictures can't you? Not really a brick wall is it? :)
 
Both sets of shots are very interesting in their own ways. But if you have 4+ lenses that's around £200 worth of filters to kit them all out, and unless you are really clumsy you are unlikely to damage more than one front element (that's without taking into account front element damage which damages the lens as well).

So is the replacement of a front element cheaper than £200?

And from looking at Stewarts photos the filters appear to give a slight loss in contrast, but sharpness wise there is no difference IMO.

EDIT: Also the 350D is 8(?)MP, how about trying it on a 12,15,24mp camera, there may very well be a difference there. (not trying to be picky but after having a look at a few of the photozone retests with the 50D the change in resolution can make a difference.)
 
Woz! said:
OK then - with more challenging lighting!

Marrakech, late at night with bright bulbs all over the place.

Spot the difference:
Click to expand...
That's interesting.

But if it was a cheap filter, then all it goes to show is that cheap filters degrade the image, which I think we all knew anyway. If it was an expensive filter though...
 
Amp34 said:
Also the 350D is 8(?)MP, how about trying it on a 12,15,24mp camera, there may very well be a difference there. (not trying to be picky but after having a look at a few of the photozone retests with the 50D the change in resolution can make a difference.)
Click to expand...
Yes, the 350D is 8MP.

I don't think there's much point trying a 24MP camera, because that will be full-frame and the pixel density will be therefore be pretty much the same as the 350D.

If we're concerned about sharpness, then re-testing with a 12MP or 15MP crop-sensor camera would be of interest, but I don't have any of them.
 
i would'nt be without a filter..L series lenses are too expensive to risk any damage
 
When I started working in the photographic trade years ago the buzz phrase then was ‘lines per millimetre’. A retailer in the south had the bright idea of using a device like a projector which when a lens was attached would project a wall size image of a test chart, he would then proceed to measure how may line per millimetre could be observed at different apertures.

He would then put a written test report in with the lens providing a so called value added extra.

For a while we had a parade of customers (usually students) who would ask how many LPM our lenses were and why could we not test them!!

One day one particularly obnoxious individual came in to the shop and demanded that we test the LPM on his camera lens.

I pointed out that ‘in the real world’ the lens would deliver far more quality than the film emulsion could resolve.

I suspect that the same is true of digital sensors.
 
Holden Caulfield said:
I suspect that the same is true of digital sensors.
Click to expand...

I don't think that is actually correct.

It has been muted that we are rapidly approaching/have reached a scenario where even top quality lenses are struggling to resolve as much detail as the higher MP sensors can resolve.

There have been a number of articles discussing the fact that DSLR sensors have all but reached their limit which can only be surpassed with an increase in lens quality.
 
Amp34 said:
Both sets of shots are very interesting in their own ways. But if you have 4+ lenses that's around £200 worth of filters to kit them all out, and unless you are really clumsy you are unlikely to damage more than one front element (that's without taking into account front element damage which damages the lens as well).

So is the replacement of a front element cheaper than £200?

And from looking at Stewarts photos the filters appear to give a slight loss in contrast, but sharpness wise there is no difference IMO.

EDIT: Also the 350D is 8(?)MP, how about trying it on a 12,15,24mp camera, there may very well be a difference there. (not trying to be picky but after having a look at a few of the photozone retests with the 50D the change in resolution can make a difference.)
Click to expand...

Let me see if I have this right. Lets all nip out and buy a 24mp camera to see if we can tell the difference with or without a filter by taking photos of a wall, something most of us will never do in real life anyway?
The test allready proved many cant see the difference, and that even when comparing imges next to each other, in the real world withoput the comparrison it would be pretty much impossible to know if a filter had been used. Wayne
 
Thanks for doing this Stuart, I use UV filters and have wondered wether it was affecting image quality. It looks like I would not be able to tell the difference
Pete
 
StewartR said:
That's interesting.

But if it was a cheap filter, then all it goes to show is that cheap filters degrade the image, which I think we all knew anyway. If it was an expensive filter though...
Click to expand...


Actually, Stewart, that's exactly what I was talking about when I asked if you could do your test in low light.

When I used my Nikon 24-70 AF-S with a Nikon NC filter (at night, with weird lighting conditions ... like Streets of London with the Christmas and New Years lights on) I would get these weird UFO light interferences. It was this which made me decide to ditch using filters
 
Woz! said:
Admittedly it's not a GREAT filter, but I decided to never use a protection filter again once I saw these two shots.
I'm really glad I noticed early in the night because I got some classic shots and they would have been ruined otherwise!
Click to expand...

I agree with you, very much having had the same experience in the night shots with my Sigma 10-20 with protective filter (Hoya Pro 1) - never used it since on that lens unless the lighting is sufficiently diffused. I was not as lucky as you and only discovered the nasty flares and haze post factum when it was too late.

My view on that, is that there is very little point to spend all those money we do on excellent glass to achive highest possible quality only to slap a piece of glass in front of it inhibiting that quality we sought. Each lens optics designed with certain performance goals and the lens optical path is usually calculated quite thoroughly for the elements and coatings it uses. Those calculatons and the lens performance do not take into account additional elements in that optical path whether coated or not. Any filter, even the most expensive, will degrade performance and inhibit the lens characteristics as they were calculated by manufacturer.

The fact that we don't see the difference in one of the many possible conditions is not reflecting the possibility of this happening in different lighting conditions. I would only be using the filter where I know for sure that I won't have that degradation significantly visible (not even in postprocessing) in the light conditions I'm shooting. Otherwise the filter comes off for me. For example for this Sigma 10-20 and my filter I established by trial that I can only safely use it when the light is very diffused and soft - like in a very cloudy weather. So I was ok using it yesterday with the filter during the snowfall with no significant effects. But I'd never use this Siggy with the filter in a bright sunny day ;)
 
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