Paranoid about my lens :)

mom2mny · 05-09-2011, 04:20 PM

I have a tamron af 70-300mm. How delicate is this lens. If I want to turn the rings do I need to be in manual? I'm afraid to turn something at the wrong time or turn something that's not even supposed to be turned! I don't want to ruin it. Will it hurt it if something pushes on the front of the hood?

Thanks!

gp1806 · 05-09-2011, 04:36 PM

If you turn the focus ring while the camera is in AF mode you will be turning the K-X gears and motor. This is not a good thing. The motor is designed to turn the gears and focus the lens not the other way around. Feel free to try the focus manually, just switch to MF on your K-X first. You can turn the zoom control any time. Your lens is not fragile, as lenses go, but all lenses should be treated carefully, it is not a baseball bat.

MPrince · 05-09-2011, 04:40 PM

I'm not familiar with that lens, but I can tell you that if you attempt to manually focus a screw drive lens while the camera is in AF mode, you risk damaging the camera's screw drive mechanism. (Not applicable to Pentax lenses with Quick Shift Focus). That's not to say that a little inadvertent nudge to the focus ring from time to time will cause damage, but you shouldn't attempt to manually focus the lens without first setting the camera switch to MF.

tibbitts · 05-09-2011, 04:53 PM

My Sigma 10-20mm won't autofocus on the short end, but I often forget to switch the camera to MF before manually focusing. I can tell right away that it's still in AF, and switch to MF, but hopefully the drive is robust enough to deal with me doing that. Also occasionally I'll have one of my longer lenses in AF and have the focusing ring rubbing up against a tree or something, and wonder why the lens won't focus, so again I'm hoping that the lens and camera was designed with possibility of that happening sometimes. So far my equipment has held up so hopefully yours will too.

Paul

epqwerty · 05-09-2011, 04:58 PM

Most of the tamron and sigma lenses function the same way. The ring at the front part of the lens is the focus ring. It should only be able to turn when in manual focus mode. If in autofocus mode when you turn it you will be turning the motor inside the camera which is a no no. The next ring that can turn is the zoom section the markings go from 70-300. That can be turn if on mf or af. However if you are focusing motor is active you should not rotate the zoom. They are independent but more moving parts means more tension. The last movable ring is the aperture for the most part it will be on A. This is movable anytime. However your camera must permit for aperture ring for the camera to work as mentioned in your other post.

KxBlaze · 05-09-2011, 10:06 PM

As others have said the only thing you have to worry about is turning the focus ring while the camera is in AF mode. Beyond that the lens is a pretty well built one and you will not damage it from normal use or by turning any of the rings. I have used this lens quite often for about a year and have had zero problems with it.

**NaClH2O** · 05-10-2011, 08:39 AM

What everyone above has said is true. Just one point. You will know immediately if you try to manually focus with the lens in AF mode. There is a major difference in the energy required to focus the lens when it is in manual focus and when it is in AF. The lens will definitely be quite stiff if you try to manually focus it when it is in AF. To get an idea of the difference, put your camera in MF and focus the lens, then put it in AF and try to focus, you will feel a big difference. An inadvertent bit of a turn won't hurt the camera, but obviously you don't want to force it around.
As for hood bumps I wouldn't worry about them. I use hoods on all my lenses. I occasionally bump them against this and that and have never had a problem. You lens isn't a baseball bat but it also isn't a delicate piece of filigree jewelry either.

NaCl(a modicum of care is all you really need)H2O

mom2mny · 05-10-2011, 08:56 AM

Thanks everyone.

timh · 05-10-2011, 09:02 AM

It's not as delicate as it looks, I dropped mine about 70cm onto a steel deck (rather loudly, causing much head-turning) and it survived entirely intact.

If you use the macro mode a lot you'll become very used to quickly switching between MF and AF - you can't zoom out until you've rolled around to a non-macro focal length.

**TER-OR** · 05-10-2011, 10:13 AM

I have this lens and find it should be in MF before trying to remove/place the hood - it's a tight fit and often cranks the screw. It's something I'm sure we should all do anyway, but this lens hood seems the tightest for me.

It's served me pretty well, but I'll warn you about purple fringing hell above 180mm. Snap a shot or two below that before zooming all the way out. I tend to protect the lens as well, but I know this one has been banged around while walking dogs and lugging the camera along.

cardinal43 · 05-10-2011, 03:12 PM

Originally posted by timh

- you can't zoom out until you've rolled around to a non-macro focal length.

I also have this lens, but I have to admit I haven't used it very much. Can you explain a little more about what you said above?

timh · 05-10-2011, 11:40 PM

Originally posted by cardinal43

I also have this lens, but I have to admit I haven't used it very much. Can you explain a little more about what you said above?

Oh, just that it's only possible to turn on 'macro' mode with the switch when the focal length is at 200-300mm (or thereabouts) so the lens is fully extended. Macro mode allows the focus ring to turn into the gold-marked area, which is where it'll be if you're shooting very close.

However, when the focus ring is in that area, macro can't be disengaged and the focal length is locked at 200-300mm - so anytime I change lenses after using it my usual routine of "retract lens, reverse hood, remove lens" is interrupted by "argh!, manual focus mode, focus to infinity, macro off, auto-focus mode" before I can retract/collapse it.

I guess it's so jarring because my other lenses are quick-shift or MF or don't extend much when zooming/focusing. I've seen other people go through the same process with that lens though, with the same "wtf" expression.

cardinal43 · 05-11-2011, 06:42 PM

Thanks for the explanation. I've never tried it in macro, so now I need to spend some time with it.

05-09-2011, 04:20 PM	#1
mom2mny Forum Member Join Date: Apr 2011 Posts: 50	Paranoid about my lens :) I have a tamron af 70-300mm. How delicate is this lens. If I want to turn the rings do I need to be in manual? I'm afraid to turn something at the wrong time or turn something that's not even supposed to be turned! I don't want to ruin it. Will it hurt it if something pushes on the front of the hood? Thanks!

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05-09-2011, 04:36 PM	#2
gp1806 Veteran Member Join Date: Mar 2009 Location: Chicago suburbs Photos: Albums Posts: 848	If you turn the focus ring while the camera is in AF mode you will be turning the K-X gears and motor. This is not a good thing. The motor is designed to turn the gears and focus the lens not the other way around. Feel free to try the focus manually, just switch to MF on your K-X first. You can turn the zoom control any time. Your lens is not fragile, as lenses go, but all lenses should be treated carefully, it is not a baseball bat.

05-09-2011, 04:40 PM	#3
MPrince Veteran Member Join Date: Sep 2006 Location: WV Posts: 1,495	I'm not familiar with that lens, but I can tell you that if you attempt to manually focus a screw drive lens while the camera is in AF mode, you risk damaging the camera's screw drive mechanism. (Not applicable to Pentax lenses with Quick Shift Focus). That's not to say that a little inadvertent nudge to the focus ring from time to time will cause damage, but you shouldn't attempt to manually focus the lens without first setting the camera switch to MF.

05-09-2011, 04:53 PM	#4
tibbitts Pentaxian Join Date: Apr 2007 Location: Oklahoma USA Posts: 2,193	My Sigma 10-20mm won't autofocus on the short end, but I often forget to switch the camera to MF before manually focusing. I can tell right away that it's still in AF, and switch to MF, but hopefully the drive is robust enough to deal with me doing that. Also occasionally I'll have one of my longer lenses in AF and have the focusing ring rubbing up against a tree or something, and wonder why the lens won't focus, so again I'm hoping that the lens and camera was designed with possibility of that happening sometimes. So far my equipment has held up so hopefully yours will too. Paul

05-09-2011, 04:58 PM	#5
epqwerty Veteran Member Join Date: Dec 2009 Location: Ontario Posts: 550	Most of the tamron and sigma lenses function the same way. The ring at the front part of the lens is the focus ring. It should only be able to turn when in manual focus mode. If in autofocus mode when you turn it you will be turning the motor inside the camera which is a no no. The next ring that can turn is the zoom section the markings go from 70-300. That can be turn if on mf or af. However if you are focusing motor is active you should not rotate the zoom. They are independent but more moving parts means more tension. The last movable ring is the aperture for the most part it will be on A. This is movable anytime. However your camera must permit for aperture ring for the camera to work as mentioned in your other post.

05-09-2011, 10:06 PM	#6
KxBlaze Veteran Member Join Date: Feb 2010 Location: California Photos: Gallery Posts: 1,602	As others have said the only thing you have to worry about is turning the focus ring while the camera is in AF mode. Beyond that the lens is a pretty well built one and you will not damage it from normal use or by turning any of the rings. I have used this lens quite often for about a year and have had zero problems with it.

05-10-2011, 08:39 AM	#7
NaClH2O Site Supporter Join Date: Sep 2006 Location: Bronx NY Photos: Gallery \| Albums Posts: 5,631	What everyone above has said is true. Just one point. You will know immediately if you try to manually focus with the lens in AF mode. There is a major difference in the energy required to focus the lens when it is in manual focus and when it is in AF. The lens will definitely be quite stiff if you try to manually focus it when it is in AF. To get an idea of the difference, put your camera in MF and focus the lens, then put it in AF and try to focus, you will feel a big difference. An inadvertent bit of a turn won't hurt the camera, but obviously you don't want to force it around. As for hood bumps I wouldn't worry about them. I use hoods on all my lenses. I occasionally bump them against this and that and have never had a problem. You lens isn't a baseball bat but it also isn't a delicate piece of filigree jewelry either. NaCl(a modicum of care is all you really need)H2O

05-10-2011, 08:56 AM	#8
mom2mny Forum Member Join Date: Apr 2011 Posts: 50 Original Poster	Thanks everyone.

05-10-2011, 09:02 AM	#9
timh Veteran Member Join Date: May 2010 Location: Wales Photos: Gallery \| Albums Posts: 445	It's not as delicate as it looks, I dropped mine about 70cm onto a steel deck (rather loudly, causing much head-turning) and it survived entirely intact. If you use the macro mode a lot you'll become very used to quickly switching between MF and AF - you can't zoom out until you've rolled around to a non-macro focal length.

05-10-2011, 10:13 AM	#10
TER-OR Site Supporter Join Date: Apr 2009 Location: Dundee, IL Photos: Gallery \| Albums Posts: 6,699	I have this lens and find it should be in MF before trying to remove/place the hood - it's a tight fit and often cranks the screw. It's something I'm sure we should all do anyway, but this lens hood seems the tightest for me. It's served me pretty well, but I'll warn you about purple fringing hell above 180mm. Snap a shot or two below that before zooming all the way out. I tend to protect the lens as well, but I know this one has been banged around while walking dogs and lugging the camera along.

05-10-2011, 03:12 PM	#11
cardinal43 Veteran Member Join Date: Oct 2007 Location: Virginia Photos: Gallery Posts: 2,412	Originally posted by timh - you can't zoom out until you've rolled around to a non-macro focal length. I also have this lens, but I have to admit I haven't used it very much. Can you explain a little more about what you said above?

05-10-2011, 11:40 PM	#12
timh Veteran Member Join Date: May 2010 Location: Wales Photos: Gallery \| Albums Posts: 445	Originally posted by cardinal43 I also have this lens, but I have to admit I haven't used it very much. Can you explain a little more about what you said above? Oh, just that it's only possible to turn on 'macro' mode with the switch when the focal length is at 200-300mm (or thereabouts) so the lens is fully extended. Macro mode allows the focus ring to turn into the gold-marked area, which is where it'll be if you're shooting very close. However, when the focus ring is in that area, macro can't be disengaged and the focal length is locked at 200-300mm - so anytime I change lenses after using it my usual routine of "retract lens, reverse hood, remove lens" is interrupted by "argh!, manual focus mode, focus to infinity, macro off, auto-focus mode" before I can retract/collapse it. I guess it's so jarring because my other lenses are quick-shift or MF or don't extend much when zooming/focusing. I've seen other people go through the same process with that lens though, with the same "wtf" expression.

05-11-2011, 06:42 PM	#13
cardinal43 Veteran Member Join Date: Oct 2007 Location: Virginia Photos: Gallery Posts: 2,412	Thanks for the explanation. I've never tried it in macro, so now I need to spend some time with it.