Genie In A Lightbox
Senior Member
Fast zoom lens provides the user the opportunity to use a wide aperture throughout the zoom range. To a user who needs it, the lens with this feature is "top grade".
I've got a unhealthy mindset/mentality
- Thread starter NikonMI6
- Start date
night86mare
Deregistered
here is clear example where your mentality is clearly shown to be extremely unhealthy
sigma 10-20 f/3.5 (constant aperture) versus sigma 10-20 f/4-5.6
http://www.photozone.de/nikon--nikkor-aps-c-lens-tests/467-sigma_1020_35_nikon?start=1
http://www.photozone.de/nikon--nikk...-56-dc-ex-hsm-lab-test-report--review?start=1
please look at extreme border measurements (For 10mm) even when stopped down. centre/border are comparable.
sigma 10-20 f/3.5 (constant aperture) versus sigma 10-20 f/4-5.6
http://www.photozone.de/nikon--nikkor-aps-c-lens-tests/467-sigma_1020_35_nikon?start=1
http://www.photozone.de/nikon--nikk...-56-dc-ex-hsm-lab-test-report--review?start=1
please look at extreme border measurements (For 10mm) even when stopped down. centre/border are comparable.
allenleonhart
Senior Member
yep. ts hasnt seen my tamron. sent to servicing twice, and i still see dust IN the LENS.:bsmilie:
anyways, if i were to compare my tamron 17-50 vs my 55-250, i'll say the cheaper 55-250 wins and i'm more comfortable shooting with that lens.
that is ofcourse if i'm not doing pano landscapes.
f2.8 just means its faster than anything with a f number larger than it. Its not necessarily better or sharper.
One good example is the Jupiter 9 85/2 its f2, but its so soft at f2 as to be 'dreamy'. It does not mean its bad either, depending on the purpose and effect sought from the lens.
Usually lens reviews and sample shots would give a better idea than just f number.
One good example is the Jupiter 9 85/2 its f2, but its so soft at f2 as to be 'dreamy'. It does not mean its bad either, depending on the purpose and effect sought from the lens.
Usually lens reviews and sample shots would give a better idea than just f number.
@Wildcat
woooo.. that's quite an amount of info..
appreciate it.. and I understand
that stopping down will bring about sharper image.. however in this case,
I would like to find out if there are lenses with variable aperture out there
that surpass lenses with constant aperture.. so one would not end up buying
a lens because he thinks that "constant f2.8 must be a good lens".
@night86mare
hmmm.. I know of this somehow as I've seen more ppl recommend
the f4 version instead of the constant f3.5 version.. will read it once I'm
home tonight..
@allen,
hmmm.. comfortable with the focal length or the image quality produced by it?
woooo.. that's quite an amount of info..
appreciate it.. and I understandthat stopping down will bring about sharper image.. however in this case,
I would like to find out if there are lenses with variable aperture out there
that surpass lenses with constant aperture.. so one would not end up buying
a lens because he thinks that "constant f2.8 must be a good lens".
@night86mare
hmmm.. I know of this somehow as I've seen more ppl recommend
the f4 version instead of the constant f3.5 version.. will read it once I'm
home tonight..
@allen,
hmmm.. comfortable with the focal length or the image quality produced by it?
coolthought
Senior Member
hey guys, just started out photog this year feb.. as an amateur.. didn't really have much
time or resources to go deep into it.. however, as i visit forums and read reviews, i've built up
a thinking that whenever a lens has an constant aperture of f2.8, i will think that lens is of
top grade..
but sometimes i wonder that there are lenses of variable aperture which produces images that
will somehow be better than some of those lenses with constant aperture? or is it really true
that those lenses with constant aperture will always be better than lenses with variable
aperture of similar focal length?
please help me understand the photog world better..
EDIT: excluding prime lenses as none of them involves variable apertures! and this category totally slipped my mind..
you got it wrong... it is a good mindset that F2.8 lenses are good..... hehe... now I can sell my F2.8 lens at a better price.....
jokes aside.... I think everyone have already set this thought out right. Just an additional note. If you look at all lens review (mag or online site like dpreivew), value for money is a rating too. There is no other way to find out whether it is a better lens that is within your budget than due diligent in doing your research and homework reading the reviews.
@Wildcat
woooo.. that's quite an amount of info..
that stopping down will bring about sharper image.. however in this case,
I would like to find out if there are lenses with variable aperture out there
that surpass lenses with constant aperture.. so one would not end up buying
a lens because he thinks that "constant f2.8 must be a good lens".
@night86mare
hmmm.. I know of this somehow as I've seen more ppl recommend
the f4 version instead of the constant f3.5 version.. will read it once I'm
home tonight..
@allen,
hmmm.. comfortable with the focal length or the image quality produced by it?
Look for reviews and look at sample picts (Eg. on Flickr).
Eg.
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=404
http://www.photozone.de/reviews
Whether you get a f2.8 or f4 for example depends on needs/wants/budget. Yes, a f2.8 lens is faster, but some need to be stopped down to f4 to be sharp. Some f4 lens wide open at f4 can be sharper than a f2.8 lens stopped down to f4. But then in some situations, when lighting is not good, an f4 lens will never be a f2.8 lens.
There is also size and weight to consider.
So no straight answer. Maybe there is.
But buy the fastest, optically best lens than you can afford
... and pay a premium 
ovaltinemilo
Senior Member
Hi TS, it depends on lighting...if lighting is good..both are comparable...if light is poor, constant aperture outperforms...
*provided the lens with constant aperture is sharp at most focal length covered*
night86mare
Deregistered
it is not fair to compare a 55-250 to a 17-50 .
wildcat
Senior Member
@Wildcat
woooo.. that's quite an amount of info..
that stopping down will bring about sharper image.. however in this case,
I would like to find out if there are lenses with variable aperture out there
that surpass lenses with constant aperture.. so one would not end up buying
a lens because he thinks that "constant f2.8 must be a good lens".
I'm sure there are out there but I don't bother to research until I'm ready to buy the lens (which normally means I got budget approval from CEO). As mentioned, cannot just say one type of lens is better than another. I can tell you what I am looking at next though: the 14-24mm f/2.8 Nikkor lens but it definitely ain't for the f/2.8 that I would get it. As others have mentioned, many factor comes into play and even if this lens was a f/4-5.6 but produces the same result, then I will still get it (coz I am not looking to shoot this lens at f/2.8 but more from f/7.1 onwards).
Look at individual lens and their pros and cons rather than aperture type. Given the knowledge you now have as to what are the difference, you should be able to make an informed decision whether to plonk the moolah down
allenleonhart
Senior Member
well i'm no exactly an expert at lens comparision. just a feeling from my photos that i shoot seems to much better more to my 55-250 than my 17-50 thats all:bsmilie:
anyways, to ts: tamron is underperforming from what i expected especially with the tech defects. maybe i'll send for servicing one last time and see how. but i tend to find it... blurrish. something like CA? i cant seem to put my finger on it. i'm not an expert!:bsmilie:
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perhaps u got a bad copy?
the tamron 17-50 non vc right? it is one of the sharpest lens in the world.... acc to photozone.de...
what problem do u have ? AF?
allenleonhart
Senior Member
dirt inside lens... ca... i dunno. minei s certainly horrendous. i find the kit lens from my friend more useful actually. and yes its non vc. 2 years old;(
i see... then no choice lah... at least it is not technical fault lah.. cos i got a fren using it.. the iq is damn power ...
even the vc one gives great pics...
allenleonhart
Senior Member
dunno lar:angry: lets just say i shoot 10 photos, all of them got slight blur. already made a point to shoot within the cherry zone of f8.:angry:
its like san guang kind of blur
Hmm maybe you should re send it for repairs and show them the pictures to illustrate your problems.
Personally , the 17-50 Tammy Non VC copy I have is very sharp leh . Got it a month ago.
So in a way , some bro is right to put out , performance/price ratio is a key consideration as well.
Generally speaking F2.8 lens are meant to be fast lens that are meant to be more superior than slower lens. But i guess , its not true all the time. But at times when a F2.8 fails , they are normally the zooms.
Sometimes , good lens dont need large appertures , for example, the ultra wides and wide angle lens for landscape photography.
Let just say , its not an unhealthy mindset, maybe just misguided ?
err.. better in what sense? sharpness or.........?
If it's just a feeling, especially in portraits, it could be that the telezoom is producing better bokeh due to thinner DoF as the FL is longer for the same subject distance, hence the picture "feels" better.. just a guess..
ovaltinemilo
Senior Member
"san guang kind of blur" sounds like a fault of the filter?? checked that n see got ghost or not?ha...
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allenleonhart
Senior Member
more like soft soft. u know rabbit fur? that kind of blurry fuzz:think:
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