Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!

SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

Tokina 800mm F8 adapter question
View previous topic :: View next topic  


PostPosted: Sun Jul 22, 2018 4:19 pm    Post subject: Tokina 800mm F8 adapter question Reply with quote

Hello,

My name is Marcel Bressers and I'm a photographer who loves to play with vintage lenses ever since I started to use Sony mirrorless A7 cameras.
Before that I was perfectly happy with my Nikon gear, but with age comes trouble and for me this meant that I am rapidly loosing my 20/20 vision especially in my right eye.
The Sony gave me new possibilities which I will explain a bit further.

After lurking around here for information before I started buying vintage lenses, I now am in a position where I have to ask for help.
I recently bought this very nice Tokina 800mm F8 lens which , according to the seller, had a Minolta MD mount.
Since I intend to use this beauty on my Sony A7III (because of my diminished eye sight) which had a magnifier and focus peaking I ordered a MD to Sony NEX adapter.
After mounting the adapter I soon realized that it was impossible to focus to infinity which came as a bit of a disappointment, because I have never dealt with such a problem before.
So I started to look around online and found out that the lens in fact has a T mount (M42x0,75mm) on which the MD adapter was mounted.
And I mounted my MD/NEX adapter on top of that.....not so good for the correct flange focal distance I guess.
I have now removed the MD adapter and am planning on getting a T mount/NEX adapter (or a T2mount/NEX adapter) to solve my infinity focus problem.

My question is: Is this the way to go or am I missing something obvious here to solve this another way?

Greetings from The Netherlands!

EDIT: And the pics are back up again....Wink









Last edited by Marcel B on Mon Jul 23, 2018 6:19 am; edited 5 times in total


PostPosted: Sun Jul 22, 2018 4:30 pm    Post subject: Re: Tokina 800mm F8 adapter question Reply with quote

Marcel B wrote:
Hello,

My name is Marcel Bressers and I'm a photographer who loves to play with vintage lenses ever since I started to use Sony mirrorless A7 cameras.
Before that I was perfectly happy with my Nikon gear, but with age comes trouble and for me this meant that I am rapidly loosing my 20/20 vision especially in my right eye.
The Sony gave me new possibilities which I will explain a bit further.

After lurking around here for information before I started buying vintage lenses, I now am in a position where I have to ask for help.
I recently bought this very nice Tokina 800mm F8 lens which , according to the seller, had a Minolta MD mount.
Since I intend to use this beauty on my Sony A7III (because of my diminished eye sight) which had a magnifier and focus peaking I ordered a MD to Sony NEX adapter.
After mounting the adapter I soon realized that it was impossible to focus to infinity which came as a bit of a disappointment, because I have never dealt with such a problem before.
So I started to look around online and found out that the lens in fact has a T mount (M42x0,75mm) on which the MD adapter was mounted.
And I mounted my MD/NEX adapter on top of that.....not so good for the correct flange focal distance I guess.
I have now removed the MD adapter and am planning on getting a T mount/NEX adapter (or a T2mount/NEX adapter) to solve my infinity focus problem.

My question is: Is this the way to go or am I missing something obvious here to solve this another way?

Greetings from The Netherlands!

PS: Here are some photos of my 'beast'









PostPosted: Sun Jul 22, 2018 6:55 pm    Post subject: Re: Tokina 800mm F8 adapter question Reply with quote

Marcel B wrote:

[...]
My question is: Is this the way to go or am I missing something obvious here to solve this another way?


I find it strange that you don't get infinity focus. If the lens is indeed a T2 mount (and I bet it is, I have one too) your putting a MD to NEX adapter on top of the Minolta T2 mount is exactly the way to proceed. When you get the T2 to NEX adapter, you will see that it has exactly the same film/sensor to flange distance (register) as the T2/MD/NEX combo.
Check the lens itself, as it is actually assembled from two parts held together by a breech lock connection. The lens has only two optical elements far at the front and if the two halves of the barrel are mated properly that could affect your infinity focus.
That's the only thing that comes to mind.


PostPosted: Sun Jul 22, 2018 7:40 pm    Post subject: Re: Tokina 800mm F8 adapter question Reply with quote

konicamera wrote:
Marcel B wrote:

[...]
My question is: Is this the way to go or am I missing something obvious here to solve this another way?


I find it strange that you don't get infinity focus. If the lens is indeed a T2 mount (and I bet it is, I have one too) your putting a MD to NEX adapter on top of the Minolta T2 mount is exactly the way to proceed. When you get the T2 to NEX adapter, you will see that it has exactly the same film/sensor to flange distance (register) as the T2/MD/NEX combo.
Check the lens itself, as it is actually assembled from two parts held together by a breech lock connection. The lens has only two optical elements far at the front and if the two halves of the barrel are mated properly that could affect your infinity focus.
That's the only thing that comes to mind.


Probably not 'exactly' the same, but certainly should be more than close enough for a 800mm lens. Typically long lenses are designed to have focus travel beyond infinity to allow for thermal expansion. They tend to be quite tolerant of adapter issues.

Are you SURE it's not capable of focusing to infinity?
If the adapter is as fault then with the lens focused as far out as it will go subjects closer than infinity will be sharp, a sign the adapter is too long)
It's possible you've been caught out by the focusing going beyond infinity. Have you actually tested it by turning the focusing ring & checking it doesn't get sharper then come into focus...
Personally I think it more likely that the lens is faulty, than the adapter combination is far enough out to affect such a long lens.


PostPosted: Sun Jul 22, 2018 8:40 pm    Post subject: Reply with quote

Welcome Marcel B

First post images don't show. For spam prevention. You can edit your links to images or upload new if you want.

I agree with all answers so far - lens not close enough to camera, focus ring turned beyond infinity, or also maybe flipped element.


PostPosted: Mon Jul 23, 2018 6:51 am    Post subject: Reply with quote

visualopsins wrote:
Welcome Marcel B

First post images don't show. For spam prevention. You can edit your links to images or upload new if you want.



Wow, even the forum rules are vintage...... Cool

Editing and uploading the pics again makes no difference.....they still won't work.
Which is a pity, because now I can not show any example shots I made with the lens focused to infinity.
But to get the idea: The moon is fully blurred at F8 and the sun (setting) is almost focused at F22 (or maybe higher I don't recall exactly)
It doesn't need that much to be able to focus correctly, I would like to be able to turn the lens just that little bit further.
On a positive note: I am able to focus up until approximately 100 meters, everything after that is blurred.
I took some gorgeous shots of sunflowers yesterday which were about 40 meters away from me.

EDIT After waking up properly.....I can put in a link to the location of the photos:

The sun at sunset with a temperature of about 24 Degrees Celsius.
http://www.marcelbressersfotografie.nl/images/DSC06915.jpg

Sunflowers taken at 11.45 AM with temperatures reaching 28 Degr. Celsius.
http://www.marcelbressersfotografie.nl/images/DSC07030.jpg

Regarding the measurements of the MD/NEX adapter....it is 25.5 mm thick and if I add the 18mm Sony FFD that amounts to the 43.5 mm Minolta MD FFD.
I have another MD/NEX adapter coming in later this week and maybe it will make a difference.
The two parts of the lens are correctly assembled (only one way possible) and it doesn't look as if there has been work done on the lens.
No signs of using tools to disassemble the lens that is.

I own a number of M42 Meyer Görlitz (300mm F4) and CZJ lenses and a nice Mamiya-Sekor 400mm F6.3 but I have never had any problems whatsoever adapting them to my Sony.
So yes, I'm a bit dissapointed now because I can not find a solution to fix this.
Unfortunately my eyesight prevents me from doing any attempts of disassembling the lens, otherwise I probably would have done that already. Wink

Thanks for the welcome and input so far, I really appreciate it!


PostPosted: Mon Jul 23, 2018 6:30 pm    Post subject: Reply with quote

Quote:


That adapter is not screwed on fully. The extra length is enough to prevent infinity focus.


Last edited by visualopsins on Mon Jul 23, 2018 10:43 pm; edited 1 time in total


PostPosted: Mon Jul 23, 2018 8:02 pm    Post subject: Reply with quote

I suspect the fault is with the adapter. Next to the letters T-Min, on the inner ring there is what seems to me like "1MM". I assume this refers to the step of the threads. If so, your adapter has the wrong threads on it. Their step should be 0.75mm. This would explain why your adapter will only screw on about a turn and a half (that's what it looks like on the photo). I would get my hands on another Minolta T2 adapter and try again. This is what comes to mind as I look at your photos.


PostPosted: Mon Jul 23, 2018 10:05 pm    Post subject: Reply with quote

Hello I'm back again and I need to apologize.
The photo with the adapter screwed on half way was to show the thread on the lens (0.75 and not 1mm) which is T mount and not M42. (can not screw any M42 adapter on the lens, I tried and it would not go on completely)
So my bad for bringing you on a false track. Cool

Secondly I have some good news to report:
- I have disassembled and assembled the lens again this morning (thanks for the tip Konicamera!) and after having done that and putting it on the camera, I noticed that the markings were 35 degrees off to the left. It can be assembled in the wrong way I guess because the first time I did this it was all right, or so I thought.
So, I loosened the three screws in the T mount and turned the lens into the correct position at 12 o clock.
- The lens will now focus to very near infinity....it is only missing it by a few more millimeters of a turn.
Photos taken at F32 are now 95% sharp and at F22 this drops to about 90% which is already a whole lot better than what I had so far. (really, really blurred!)

I'm now seriously thinking about buying a T2 mount/NEX adapter and see if that will do any better.
As far as I can see the adapter is exactly as long as it should be, but the results I'm getting still point in the direction of a adapter that is a little too long.
I can definitely say that I am not able to go beyond infinity....it stops just a little before I reach infinity so the adapter is definitely not too short.

Photos taken at 280 meters and F16 look kind of soft, but at a 100 meters they are sharp as a tack.
I am also able to focus correctly on the shortest focal range of about 16.50 meters. Shorter is not possible but that is how the specs say it should be.

I took a photo of the moon about an hour ago and it was acceptable at best.
Here it is:

The 400mm Mamiya -Sekor did a better job:


On a shorter range (40 meters) the lens performs well:


Little falcon resting and putting his feet up at 35 to 40 meter:



Test shot (F16) at 16.5 meters:



Test shots at 280 meters:





So there you have it.....tomorrow I'm out working and Wednesday it is time to get me that T mount/NEX adapter. Wink
Thanks for the input again guys!


PostPosted: Thu Jul 26, 2018 2:44 pm    Post subject: Reply with quote

Time for the final update..... Cool

After receiving the T mount/NEX adapter which made no difference, I decided to take the plunge and look at the lens a bit closer.
Since this is a 2 element in one group lens with a fixed element at the front, I took a closer look at the rear half of the lens.
After carefully removing the end piece which contains a piece of glass that is there to protect the lens from getting dirty on the inside, I turned the focus ring to the infinity position to be able to inspect the rear glass element.
That element was in pretty good shape, there was only a little bit of accumulated dirt on it which I wanted to remove.
As soon as I started to try and get the lens element out I noticed that it was not firmly tightened, but was actually loose and could be removed by simply using my finger to turn it all the way out. Shocked
And when it got out, I noticed that the element was also loosely in it's holding frame (hope you understand what I'm talking about)
So I cleaned the element carefully and put it in it's frame again securely tightening it this time.
Then I proceeded by putting the frame back in the lens and tighten that firmly as well.
I put the end piece with the protective glass back in place and that was it.
The lens now focuses perfectly to infinity and all of my troubles are over and I'm ready to photograph the Lunar Eclipse tomorrow night..... Whoo Turtle


PostPosted: Thu Jul 26, 2018 3:15 pm    Post subject: Reply with quote

Yay! Happy Dog


PostPosted: Thu Jul 26, 2018 3:43 pm    Post subject: Reply with quote

Congrats looking forward to seeing results


PostPosted: Thu Jul 26, 2018 4:00 pm    Post subject: Reply with quote

Marcel B wrote:
Time for the final update..... Cool

After receiving the T mount/NEX adapter which made no difference, I decided to take the plunge and look at the lens a bit closer.
Since this is a 2 element in one group lens with a fixed element at the front, I took a closer look at the rear half of the lens.
After carefully removing the end piece which contains a piece of glass that is there to protect the lens from getting dirty on the inside, I turned the focus ring to the infinity position to be able to inspect the rear glass element.
That element was in pretty good shape, there was only a little bit of accumulated dirt on it which I wanted to remove.
As soon as I started to try and get the lens element out I noticed that it was not firmly tightened, but was actually loose and could be removed by simply using my finger to turn it all the way out. Shocked
And when it got out, I noticed that the element was also loosely in it's holding frame (hope you understand what I'm talking about)
So I cleaned the element carefully and put it in it's frame again securely tightening it this time.
Then I proceeded by putting the frame back in the lens and tighten that firmly as well.
I put the end piece with the protective glass back in place and that was it.
The lens now focuses perfectly to infinity and all of my troubles are over and I'm ready to photograph the Lunar Eclipse tomorrow night..... Whoo Turtle

Congratulations!
Optically this lens is quite good for the time. My only regret about it is the absolutely tiny tripod footing. Even a slight gust of wind is often enough to make it wobble about. I used an old paint roller extensible handle to make an adjustable support with a Y-shaped end, like those used once upon a time to hold up muskets. Works wonders for sharpness. Smile


PostPosted: Fri Jul 27, 2018 9:17 am    Post subject: Reply with quote

Glad you sorted it in time Happy Dog
You'd have been kicking yourself if you'd not found out till tomorrow!


PostPosted: Fri Jul 27, 2018 11:51 pm    Post subject: Reply with quote

Well, it worked like a charm! Whoo Turtle



Last edited by Marcel B on Sat Jul 28, 2018 12:11 pm; edited 1 time in total


PostPosted: Sat Jul 28, 2018 6:30 am    Post subject: Reply with quote

Nice shot well done.
Like Dog
The whole event was eclipsed by clouds here, after weeks of clear skies we had a thunderstorm throughout totality. Rolling Eyes


PostPosted: Sat Jul 28, 2018 3:07 pm    Post subject: Reply with quote

Excellent eclipse image!

Like 1 Like 1


PostPosted: Thu Aug 05, 2021 9:43 pm    Post subject: Reply with quote

My apologies for resurrecting this ancient thread.

I recently bought a copy of this lens, also with the Minolta MD mount, and I seem to have a massive focus issue. I can only focus from around 15 to 30m when i hit the infinity mark on the focuser. The lens seems to have been cleaned and then reassembled incorrectly as i can just screw the focuser all the way off, but it does not go as deep as the one in the first post. I have tried to reattach it a few different ways, but can not get it any better than it was. I please need someones assistance.


PostPosted: Thu Aug 05, 2021 10:26 pm    Post subject: Reply with quote

Welcome neildlr@gmail.com

Can you post photos showing the problem? Thanks!


PostPosted: Fri Aug 06, 2021 4:29 pm    Post subject: Reply with quote

I can un-screw the focus all the way to the point where it comes off. The best that I can get it can be seen below. I move the back end to the shortest focus, then screw the focuser on, and then align the back with the top of the lens. This is the only way that I can get the infinite focus point to be as short as possible but it still feels too long. If I compare the distance between the focuser and the tripod mount with that of the lens in the first post of this thread I can see that mine should be way shorter.

I also think the rear element should be closer to the mount but I just can't get it closer.




I know the rear element is quite dirty, that seems to be on the inside, and I don't have the tools to remove it.


PostPosted: Fri Aug 06, 2021 5:41 pm    Post subject: Reply with quote

Focusing helical threads have multiple starting points. Unscrew focus helical then try another starting position. You may have to try several starting positions before finding the correct one.

I notice this lens has two tripod mounts...anybody know what's up with that?


PostPosted: Fri Aug 06, 2021 6:06 pm    Post subject: Reply with quote

This is where the frustration comes in. I sat for nearly two hours last night trying different starting points and different focus distances for the mount end. The best I managed was to start the mount end at minimum distance and have the 100m marker at the top. Any other starting point has the focus scale start in a non vertical position (which is how I received the lens and knew something wasn't right)

Is it possible that the grip and helical thread are misaligned ?


PostPosted: Fri Aug 06, 2021 6:39 pm    Post subject: Reply with quote

...

Last edited by Blazer0ne on Tue Feb 22, 2022 6:33 pm; edited 1 time in total


PostPosted: Sun Aug 08, 2021 1:19 am    Post subject: Reply with quote

neildlr@gmail.com wrote:
. . .
I please need someones assistance.


Hi, neildlr. I also have a copy of this 800. How can I help?


PostPosted: Sun Aug 08, 2021 4:36 am    Post subject: Reply with quote

visualopsins wrote:
. . .
I notice this lens has two tripod mounts...anybody know what's up with that?

This lens separates into two pieces. The nearest to the camera half has a black tripod mount. There are also three silver receptacles:
One below the depth of field scale is for an "external gunsight". And there are two on the focus ring for a "vernier focusing lever".
The gunsight and focusing lever can be stored in the base of the tripod mount.


#1






Marcel B wrote:
. . .
Since this is a 2 element in one group lens with a fixed element at the front, I took a closer look at the rear half of the lens. . .

Perhaps Marcel B has a different version from my lens? (I don't think so.) But according to literature, my (Vivitar) copy has four elements in two groups.
Either way, what matters is Marcel B has shown us this lens can capture sharp, beautiful images. Bravo!


#2