Sharpness test shots: MZD 75-300 II with and without UV filters

Olfdee wrote:

NZ Scott wrote:

many lenses behave in different manner at close and far focus distances (eg. focus breathing), also in your room light was not strong enough (looking at exposure times) and not directional enough to trigger possible side effects in filters (and lens itself!).

What side effects are you talking about?

Flare and stray light from not dampened internal reflections of the filter - if they are too weak (and they will be without strong light source), they won't visibly affect contrast of an image.

You will be pleased to hear that under real-world outdoor shooting conditions, I have never experienced any flare at all with this lens when shooting with and without filters attached - some 4000 shots, at least.

As for contrast loss, I also haven't noticed any problems.

On a few occasions in Africa I removed the UV filter when shooting at long focal lengths in the belief that this would help maximise image quality. However, I didn't notice any difference with the filter removed - and certainly no gain in contrast.

"BTW there is a good chance in your room UV (and IR) was cut by the window glass, so one more variable (potentially) affecting outdoor results was taken out of the equation."

Shots were taken next to my balcony, with an open ranch slider, so there was nothing filtering the light.

S

The talk about UV's being detrimental to IQ isn't an urban legend.

When I was using a premium telephoto zoom with good DSLRs, once in a while a wildlife shot would be fouled, and it was determined to be from the filter. Not something I could reproduce at will, though, so I initially doubted myself. But then others would talk of the same sporadic results, and in the end the consensus was that filters were the culprit.   And with filters out of the picture (heh), the problem didn't recur.

I also had issues with a premium vari-ND filter on the telephoto. Only for one study series, one day, and it was quite disappointing. But I didn't want to chance having that occur again.  Again, it was with a telephoto zoom at the long end (haven't seen this with normal lenses, however).    Then, I specifically recall using my first DSLR prime, where I could detect a nuanced difference in contrast, better w/o the filter.  At that time my discernment was in development, so it struck me that I noticed the difference.    So for these reasons I found it best not to bother with the filters unless they were needed for specific protection (like blowing sand conditions, weather sealing a front element that required it, etc.). I don't recall the filter brand used at that time, but I normally don't scrimp on that extra layer of glass in front of a premium lens.

The precaution isn't a fallacy, but there are no guarantees everyone will experience it with any regularity. Those that have experienced it choose to err on the side of caution. IOW, YMMV.

Wormsmeat wrote:

Am I the only one that thinks the 1st (naked) shots are more saturated? Looking at the red on the arm on the right for example...

Possibly, but you're assuming that the 1st shot in each series is the naked one.

I actually played a little trick and rearranged the order of the photos, anticipating that the anti-filter brigade would extol the virtues of the first photo in each series.

S

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Wormsmeat
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NZ Scott wrote:

Wormsmeat wrote:

Am I the only one that thinks the 1st (naked) shots are more saturated? Looking at the red on the arm on the right for example...

Possibly, but you're assuming that the 1st shot in each series is the naked one.

I actually played a little trick and rearranged the order of the photos, anticipating that the anti-filter brigade would extol the virtues of the first photo in each series.

S

interesting thread but you'd need to test across a wide range of conditions to have certainty that any filter will never degrade IQ. fWIW my own tests on a very expensive pro lens for my Sonly DSLRs showed Hoya digital HD clear filters DID degrade IQ so it can happen - this was on a tele lens at the long end, in outdoor conditions.

Marco Cinnirella wrote:

NZ Scott wrote:

Wormsmeat wrote:

Am I the only one that thinks the 1st (naked) shots are more saturated? Looking at the red on the arm on the right for example...

Possibly, but you're assuming that the 1st shot in each series is the naked one.

I actually played a little trick and rearranged the order of the photos, anticipating that the anti-filter brigade would extol the virtues of the first photo in each series.

S

interesting thread but you'd need to test across a wide range of conditions to have certainty that any filter will never degrade IQ. fWIW my own tests on a very expensive pro lens for my Sonly DSLRs showed Hoya digital HD clear filters DID degrade IQ so it can happen - this was on a tele lens at the long end, in outdoor conditions.

I've also done a filter comparison outdoors but found that it was impossible to control changes in atmospheric conditions (such as humidity/haze), which are a significant factor affecting image quality.

S

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"When words become unclear, I shall focus with photographs. When images become inadequate, I shall be content with silence." Ansell Adams.