[repaap]

tcbubbleleo, hope you found that lens...

Here is some shots, to wake this thread up





Xposted( i'll put some other shots up too later...

[uttam.hathi]

budget usd300 any seller 28-70/ or 20 35

[uttam.hathi]

i have never used a hsm or equivalent lens, am looking for a tokina 28-70 atx pro 1st version , my question is how slow is the auto focus say compared to kit lens 18 55

[repaap]

I have AT-X 270 II vers, and focus speed is maybe little faster than with kit-lens.

Here is some shots from my AT-X 235





just to wake this thread up

[uttam.hathi]

tokina 20-35/2.8 pro is what was really wanted, but could not get one so i settled for at-x pro 28-70 ver I Supposed to be angenieux design but a older lens on electronics. is being shipped from japan thus hope its the japanese mkt version (research on google) and have brought a promaster 19-35/3.5 cheap cosina cousin, basically need it to shoot landscapes , lets see
thanks for the info on focus speed

[repaap]

Nice,

I think that your 28-70 won't let you down. Need to get used to it and be prepaired for buying bigger hood to it. It makes a differense.

So, post some shots when you get it

[Peter Zack]

I just picked up the Tokina AT-X Pro 28-70mm f2.6-2.8 (Japanese version that just shows f2.8 on the front) 77mm Filter thread. This is the one that does not take the bayonet hood but the screw on hood.

Before I email the Ebay seller, I want to check and make sure I'm not doing something wrong with the odd focus clutch this lens has. It sounds a bit noisy (almost a grinding noise sometimes but not always) and if the camera is in single shot AF and the clutch is in the AF position, the lens won't always focus. For example, it will focus somewhat close (maybe a meter) and then if I leave the focal range alone (say leaving it at 70mm) and just focus on something distant, the focus ring turns to infinity but the actual focus does not, it's still at the 1 meter focus.

So from the reading I've done on this lens, it seems that to go to manual focus, you turn the camera to MF, then turn the focus ring to the point where the clutch will allow the focus ring to be put in the MF position. That seems to work as all the research I read.

To go back to AF, the lens focus ring will move back into the AF spot (pushing it forward) at any spot. So unlike going to MF, you don't have to find the exact spot where you were last in AF. Is that correct?

What I'm guessing is wrong with this lens is, the clutch is defective (not properly locking the lens in AF mode) or the part that actually moves the glass to focus is worn out and even though the camera motor spins the focus ring, the inner barrel that moves the lens elements isn't engaging any more. So the lens elements are not focusing.

Also, my understanding is that if the MF/AF ring on the lens is in the MF position but the camera switch is in the AF position, the lens AF is still supposed to work. The same thing happens when it's set up like this. The focus ring will turn and the lens may or may not get the correct focus. Also if both are in the MF position, I can't always get it to focus using the lens focus ring. It spins fine but particularly from about 20 feet to infinity, it may or may not focus sharply or at all.

Finally, with the lens off the body, the AF screw turns through the full range from infinity to close focus. So that works but just may not be engaging the inner focus barrel?

Last, the zoom ring is a bit tight from 35mm to 28mm. It may be that the lens was dropped even though it does not look like it.

Thoughts? Am I doing something wrong in setting the clutch?

---

Last edited by Peter Zack; 09-20-2012 at 08:41 AM.

[repaap]

Hi, way that I see it, you are doing it right. All that you say match my experience in using the lens...exept focusing part. Mine focuses just fine allthe way. Hunting sometimes, yes. But it still finds on target. And zoom ring moves fluently allthe way too. There is something wrong with your lens...IHMO.

[Konstantinos]

Hello everyone. I'm a regular reader of the forum even though this is my first post.

Peter Zack and everyone else, I'm also having problems with my Tokina AT-X Pro 28-70mm f2.6-2.8 which I won recently at a very good price on ebay. From what I've read and seen, it's the II version because it has a bayonet mount for a lens hood. The seller didn't know much about the condition of the lens so I just bid based on luck.

The switch from AF to MF and back is done as Peter Zack describes using the clutch colar at certain positions. My lens shows focus problems similar to the those that Peter Zack describes. I've shot some test photos and came to similar conclusions, although I want to shoot more at the weekend to verify the problem and describe it thoroughly. So I'll update on the focus issue sometime next week. (By the way the photos I managed to take in focus look great!)

Apart from that, the lens seems to have a split personality:

1) Although it's maximum aperture is claimed f2.6, the lowest f number I've seen on the K-5's LCD is 2.8...
2) This f2.8 can stay for a focal range from 28 mm to about 37 mm. From about 37 mm to the tele end of 70 mm, the lowest f number indicated on the LCD is f5.6... So if I have the aperture wide open at 28 mm, the LCD indication switches from 2.8 to 5.6 the moment I pass the 37 mm while I'm zooming in...
3) And the funny part is that from the moment I pass the 37 mm and upwards, the lens thinks it's a prime tele lens. As I reviewed the photos both in camera and in Lightroom, it registers a focal length of 400 mm...
4) It also owns a fake ID, as it presents itself to Lightroom as a Pentax F 28-80 mm F3.5-4.5... Go figure...

Like I said, I'll report more thoroughly about the focusing issue next week.
In the mean time, has anyone else had a similar experience with a bad behaving aged Tokina lens? Is there any chance of making it a good boy again?

[repaap]

Mine AT-X also identyfies it self as pentax-lens but other than that it works just fine I have vers. II, althought mine says at front 2.6-2.8. And I can use F2.6 only by rotating aperture ring manually(@exif it says F - )you can see difference at shots...

Have to check mine version too. But I haven't had any big problems with mine...

[Peter Zack]

I think from the reading I've done, no manufacturer has programmed the f2.6 setting into their cameras. Probably since this might be the only lens ever built that can be set to 2.6. So they all see it as a 2.8. That's not much of a variance to matter in exposure terms.

Further testing with the lens I have, has me convinced the inner lens barrel/cam is worn out or damaged. If you take the lens off the camera and shake it, you can hear and feel a fair amount of movement. Not some little click of a loose screw but you can feel the weight of something heavy moving. I'd guess it's the lens groups moving back and forth as a unit.

After taking a 150 test shots or so, it seems the lens will focus sometimes (sort of). I'd guess if I shake the lens the right way, the lens group is almost in the correct position to allow the AF to at least move the lens groups. So AF appears to work and the camera thinks it's locked on.

When I do that, it front focuses like crazy. IE if the subject is "focused" 15 feet away at 70mm, the focus is actually about 20 feet. That front focused part of the image is very sharp. Looking at that tells me the entire lens group inside has shifted from where it should be.

The seller wrote me back and offered $40 for my trouble. Ah no, I'll be going to Paypal for a full refund please. I wish it was possible to fix this for that price but I highly doubt it. It's a solid lens and I will find another one for sure.

[repaap]

Yea, I think it is better for you, just return it.

It is broken, and I don't know what it would cost to repair it...I have none of similar things. It should be really solid lens all a round. Hope it will go well.

I think from the reading I've done, no manufacturer has programmed the f2.6 setting into their cameras. Probably since this might be the only lens ever built that can be set to 2.6. So they all see it as a 2.8. That's not much of a variance to matter in exposure terms.

Further testing with the lens I have, has me convinced the inner lens barrel/cam is worn out or damaged. If you take the lens off the camera and shake it, you can hear and feel a fair amount of movement. Not some little click of a loose screw but you can feel the weight of something heavy moving. I'd guess it's the lens groups moving back and forth as a unit.

After taking a 150 test shots or so, it seems the lens will focus sometimes (sort of). I'd guess if I shake the lens the right way, the lens group is almost in the correct position to allow the AF to at least move the lens groups. So AF appears to work and the camera thinks it's locked on.

When I do that, it front focuses like crazy. IE if the subject is "focused" 15 feet away at 70mm, the focus is actually about 20 feet. That front focused part of the image is very sharp. Looking at that tells me the entire lens group inside has shifted from where it should be.

The seller wrote me back and offered $40 for my trouble. Ah no, I'll be going to Paypal for a full refund please. I wish it was possible to fix this for that price but I highly doubt it. It's a solid lens and I will find another one for sure.

[repaap]

I took my AT-X 270 out, and it was solid, as one should be...

Here is some shots, with it.

[repaap]

Bump!

[cbope]

More nice shots repaap! I haven't shot much with my AT-X 280 recently, mostly I have been using the kit lens and my F 50mm macro. But with ruska now starting, I should get out the Tokina.