All Forum Comments
looks like you're focusing to the right of centre !? You have got focus select set to Centre ?? right !?
Comment by Cisco posted on OOF using DA*16-50 at 25/04/2011 - 12:32
AFIK you can't link to the image gallery ! You'll need to use Photobucket or similar to host the image
Comment by Cisco posted on Inserting photos at 20/04/2011 - 11:39
boudou701 wrote:
Guessing it's not af right?
You can see it's not ! pic of mount end !! Guessing it's not af right?
Comment by Cisco posted on FS: Pentax-A 35-105mm f3.5 at 19/04/2011 - 16:58
fatspider wrote:
Ah the age old question of filters, love em or hate em
I always used to have a UV filter on my lenses then I read a thread on this very forum and now have none at all, other than a couple of cheap CPLs for occasional use.
Your going to get lots of advice on this one but at the end of the day only you can decide which way to go.
Any filter is going to affect the quality of an image to some degree, how visible this is will depend on the filter and circumstances.
There is the argument why buy expensive lenses and then put a cheap filter in front of it, but ther is also the argument that a filter will protect the front element from knocks, this in itself has been debated as to how much protection a filter really offers.
My advice:
Ditch the filters and take more care with your lenses, always use the lens hood which will help to protect from knocks. if your going to sling the camera over you shoulder after every shot then get into the habit of replacing the lens cap.
Filters can have their uses in extreme conditions but for day to day photography you dont need them.
Exactly !! +1 ^^^Ah the age old question of filters, love em or hate em
I always used to have a UV filter on my lenses then I read a thread on this very forum and now have none at all, other than a couple of cheap CPLs for occasional use.
Your going to get lots of advice on this one but at the end of the day only you can decide which way to go.
Any filter is going to affect the quality of an image to some degree, how visible this is will depend on the filter and circumstances.
There is the argument why buy expensive lenses and then put a cheap filter in front of it, but ther is also the argument that a filter will protect the front element from knocks, this in itself has been debated as to how much protection a filter really offers.
My advice:
Ditch the filters and take more care with your lenses, always use the lens hood which will help to protect from knocks. if your going to sling the camera over you shoulder after every shot then get into the habit of replacing the lens cap.
Filters can have their uses in extreme conditions but for day to day photography you dont need them.
Comment by Cisco posted on Filters cheap or expensive? at 19/04/2011 - 11:50
what shot ? where ? :
Comment by Cisco posted on Focus stacking at 18/04/2011 - 19:11
I couldn't agree more ! NO free pics !
But then the same could be said of charities, the more we put our hands in our pockets the less the government provides !?
But we still end up paying either way
But then the same could be said of charities, the more we put our hands in our pockets the less the government provides !?
But we still end up paying either way
Comment by Cisco posted on copyright.. at 18/04/2011 - 19:00
No problems with mine ! must have got a good one !!
Beats my 18-250, which they seemed to like, except on edge CAs maybe.
I love it
Beats my 18-250, which they seemed to like, except on edge CAs maybe.
I love it
Comment by Cisco posted on 18-135 has been slaughtered by Photozone at 17/04/2011 - 15:27
CPLs are the worst ! You have to rotate them to use them ! then they won't let go when you try to take them off
Comment by Cisco posted on How to remove a stuck filter - 3 methods at 16/04/2011 - 17:17
johnriley wrote:
It's measuring a phase difference isn't it? When it finds the cancel-out point as received by the AF sensors it stops moving the lens. If the lens carries on a bit because of play in the mechanism then focus will be slightly out and could be corrected for.
However, this may vary depending upon how far the mechanism has travelled. Something whizzing from infinity to macro distances, for example, whould take more stopping than something whizzing from 1.2m to 1.0m
Then again, it may also vary depending on direction of travel. Going from macro to infinity will certainly be stopped pretty quickly when it hits the limit of travel.
Lots of variables and potential for error in an AF mechanism I suspect. However, focusing tests have shown that manual focus is also very unreliable, basically because the eye adapts and can be poor at judging the sharpest point. Try it. Focus on something, note the position of the lens. Focus again and note how different your second and subsequent choices are.
Fortunately despite all this getting normal, sharp images still seems to happen most of the time.
Thank you for your Polite answer John It's measuring a phase difference isn't it? When it finds the cancel-out point as received by the AF sensors it stops moving the lens. If the lens carries on a bit because of play in the mechanism then focus will be slightly out and could be corrected for.
However, this may vary depending upon how far the mechanism has travelled. Something whizzing from infinity to macro distances, for example, whould take more stopping than something whizzing from 1.2m to 1.0m
Then again, it may also vary depending on direction of travel. Going from macro to infinity will certainly be stopped pretty quickly when it hits the limit of travel.
Lots of variables and potential for error in an AF mechanism I suspect. However, focusing tests have shown that manual focus is also very unreliable, basically because the eye adapts and can be poor at judging the sharpest point. Try it. Focus on something, note the position of the lens. Focus again and note how different your second and subsequent choices are.
Fortunately despite all this getting normal, sharp images still seems to happen most of the time.
If it was a closed-loop servo system then then that would answer my question, but as I (and many others) suspect it isn't ! It simply moves to 'A' position ! (right or wrong)
Comment by Cisco posted on Why do some lenses have front/back focus issues? at 16/04/2011 - 16:29
I think you answered your own question !?
As for cumulative, the panel's still out on that
As for cumulative, the panel's still out on that
Comment by Cisco posted on Quick question - which 'type' of focus adjustment at 16/04/2011 - 16:25
