DFA*70-200 Question


malvern_man

Link Posted 07/05/2021 - 22:57
Hi all,

My DFA*70-200 arrived today, when I put in onto my K3 III theres some very, very slight rotational movement (it's the same on my K3 II too) is this normal? Could it be because of the lenses size and weight that the movement is being exaggerated. I have taken a few test shots in the street and garden and all seems fine, well it's more than fine, the lens is amazing.

I don't notice any movement on my DA* 50-135.

Regards, Chris.
My Website

Chrism8

Link Posted 08/05/2021 - 07:47
Yes, mine is the same, don't worry about it
Chris

www.chrismillsphotography.co.uk

" A Hangover is something that occupies the Head you neglected to use the night before".

-------------------------------------------------------------
K1 - Sigma 85mm F1.4, Pentax DFA 150 -450 F4.5 / 5.6, Pentax DFA* 24 - 70 F2.8

Samyang 14mm F2.8, Pentax DFA* 70-200 F2.8

K3iii + K3ii + K5iis converted to IR, Sigma 17 - 70 F2.8, Pentax 55 - 300 F4.5 / F5.6 PLM

malvern_man

Link Posted 08/05/2021 - 12:54
Chrism8 wrote:
Yes, mine is the same, don't worry about it

Thank you Chris.

Regards, Chris.
My Website

davidwozhere

Link Posted 09/05/2021 - 01:16
Whilst perhaps not worrying about it I would be a bit disappointed having paid over a grand for the lens and 2 grand for a camera, one or both of which are not up to four figure standard and are most certainly not as weatherproof as the promotional guff claims them to be. Have you got the confidence to take it out in the rain? I would say it's worth a complaint on those grounds alone. Is the lens still in guarantee?
Both the *istDS and the K5 are incurably addicted to old glass

My page on Photocrowd - link

RobL

Link Posted 09/05/2021 - 08:18
Hang on David, no-one has said anything about the kit not being weather resistant! My copy of the lens has a very slight movement in the barrel itself, not at the mount, is that what we are discussing? It has been out in all conditions without any ill effects to lens or camera and the results from it are superb. I have toyed with buying the new f4 70-210 just for being lighter but I know I would look at the results and always question whether I should have taken the f2.8 70-200 instead.

Even the most cynical of reviewers so far have acknowledged the new camera is excellent.
Last Edited by RobL on 09/05/2021 - 08:24

malvern_man

Link Posted 09/05/2021 - 11:33
Hi all,

The very, very slight movement is in the mount, I've also tried it on my K3 II and that's the same too.

Regards, Chris.
My Website

johnriley

Link Posted 09/05/2021 - 12:34
If you are talking about a small rotational movement, I've observed this is several marques and their lenses. As long as the lens is in firm contact with the mount a miniscule rotation doesn't seem to have any effect. It should be miniscule though and probably would go unnoticed unless we start twisting lenses routinely to check.
Best regards, John

malvern_man

Link Posted 09/05/2021 - 13:45
johnriley wrote:
If you are talking about a small rotational movement, I've observed this is several marques and their lenses. As long as the lens is in firm contact with the mount a miniscule rotation doesn't seem to have any effect. It should be miniscule though and probably would go unnoticed unless we start twisting lenses routinely to check.

Thank you John,

The rotational movement is minuscule and the lens has worked fine on the couple of times I've tried it. I'm thinking that the movement could be exaggerated by the sheer size and weight of the lens.

Regards, Chris.
My Website

Lev

Link Posted 09/10/2021 - 09:46
I have K-3, K-1 and 7 lenses. I can confirm that no matter what lens I put on eather body, I can very slightly move the lens in rotational direction. This is more pronounced in case of say 70-200 because it's heavier.

I was so intrigued went to camera shop and picked up Fuji XT4 with a tiny lens attached on it. Despite the fact that it felt attached to the bayonet quite firmly, I could still feel a clutch/pin mechanism engaged every time I was rotating the lens left and right. I would put there 50-140 but they only had this one so I left this little coffee/camera shop with just an imaginations how heavier lens would feel on Fuji in this regard.

In general, most people or professional techie folks are saying yhat this is normal and could not be otherwise because the lens would have trouble locking or unlocking, or even worse, unlocking accidently, so there MUST be some space or how techie guys would say backlash.

Interesting point here already mentioned is whether or not it will affect weather resistance?? I think that it doesn't matter if the gasket moves a little bit rotationally unless it is properly sealed against the mounting surface. Anyway, would be great to see some proof.

doingthebobs

Link Posted 09/10/2021 - 15:13
Just had a check with my K3 (original) with the 43mm LTD. Yes there is a very small amount of play.
If you think about it, there must be a little.
When you put a lens on the camera, as the rotation gets to the point of the release pin snapping into lock position the lens can be moved a very slight bit more. It has to do this to ensure the lock pin has enough tolerance to operate properly to lock the lens on the camera but still be easy to release when you want to remove the lens. Moving parts need to have some space to allow movement, just enough but not too much!

As the water resistance gasket is circular, it will still work fine, being hard up against the camera mount during the attachment of the lens.
Bob

HarisF1

Link Posted 09/10/2021 - 19:16
Also with the DFA lens having a larger body diameter, a small rotation is more likely to be noticed.
All the gear with no idea
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