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Tamron SP 70-150mm f2.8 Soft Focus apperture Problem
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PostPosted: Tue Oct 27, 2020 9:26 pm    Post subject: Reply with quote
Arutemu wrote:
Darn, I just purchased the same lens and it has the same problem. The aperture gets closed as soon as an adapter is attached and I lose control of it - it stays closed and cannot be opened. I also noticed that the mount on mine looks different from the pics above. It is lacking the rectangular opening rear baffle. Is that a different version of the Adaptall mount I am not aware of, or am I screwed and the lens is missing its rear? I paid $20 for it, so no big loss, but I really wanted to make it work...


Adaptall-2 lenses can behave slightly differently depending on which adaptor is being fitted, also it can be important (possibly only with some adaptors) to ensure the aperture ring on the lens is set to wide open when fitting the adaptor, to enable the adaptor to align itself and couple correctly.
Set the lens aperture ring to "wide open", align the blue dots, then twist the two together until they lock. Ensure the little coupling lugs on the mount have engaged in the appropriate recesses on the lens, if not they can usually be "encouraged" to slip into place. Some mounts can/will develop an amount of stiffness, not allowing the coupling lugs to rotate freely, a drop or two of appropriate lubricant applied to the moving surfaces in the mount will usually free things up.Where applicable, as on the PKA mount, the lens can then be put into "auto" mode by depressing the extra control on the side of the adaptor and rotating the aperture ring to f/32, or whatever the smallest aperture is.

I've been using Adaptall lenses since the '70's, they really are ridiculously sturdy, but, inevitable, time will have taken it's toll on some of them Wink

YMMV - good luck Smile


PostPosted: Wed Oct 28, 2020 5:30 am    Post subject: Reply with quote
kypfer wrote:
MinniMe wrote:
I also looked up the prices which are asked for this lens.... ridicilous or it is one of the best ever made.


I think it's the soft-focus novelty factor which pushes the price up on this model, that and the fact that it's not common. I have a Fujinon 85mm soft focus and they can command very high prices these days as well ... I acquired mine when 42-screw was "old-fashioned" and stuff like that could be bought for little more than peanuts Wink

Just as well you managed to fix it yourself. When I enquired about getting my Tamron Adaptall-2 28-200mm serviced I was told by the Tamron Service Agents in the UK that it was "a service they could no longer provide" - neither were they prepared to release a copy of the disassembly instructions!


Probably the soft focus vintage atmosphere attracts hipsters with deep pockets. Unbelievable what these guys pay nowadays for an Olympus Mju-2 or a Yashica T5.


PostPosted: Wed Oct 28, 2020 1:45 pm    Post subject: Reply with quote
kypfer wrote:


Adaptall-2 lenses can behave slightly differently depending on which adaptor is being fitted, also it can be important (possibly only with some adaptors) to ensure the aperture ring on the lens is set to wide open when fitting the adaptor, to enable the adaptor to align itself and couple correctly.
Set the lens aperture ring to "wide open", align the blue dots, then twist the two together until they lock. Ensure the little coupling lugs on the mount have engaged in the appropriate recesses on the lens, if not they can usually be "encouraged" to slip into place. Some mounts can/will develop an amount of stiffness, not allowing the coupling lugs to rotate freely, a drop or two of appropriate lubricant applied to the moving surfaces in the mount will usually free things up.Where applicable, as on the PKA mount, the lens can then be put into "auto" mode by depressing the extra control on the side of the adaptor and rotating the aperture ring to f/32, or whatever the smallest aperture is.

I've been using Adaptall lenses since the '70's, they really are ridiculously sturdy, but, inevitable, time will have taken it's toll on some of them Wink

YMMV - good luck Smile


Yep. Did all that. The adapter is not the problem - it works like a charm with all my other Adaptall lenses. I think something is wrong with the 70-150mm here. The adapter fits just fine, just like intended. However, the moment I put the adapter on, it pushes the pin in the lens rear, which closes the aperture and I can no longer open or close it while the adapter is on. That is why I was suspecting the lens might be missing the rear baffle (visible on another model of the same lens in pics earlier in this thread). So my questions are:

1) Why is my lens behaving as described?
2) Why do the lens rear mounts look so different when both lenses are Adaptall 2?
3) Is mine ruined somehow because it is missing that rear piece (it does not look like something's been removed)?


PostPosted: Wed Oct 28, 2020 2:19 pm    Post subject: Reply with quote
It looks ok with me. Trying a different adaptall-2 adapter to exclude a problem with this particular lens would be my advice. Also the mount looks a bit bent to me, but that might be an optical illusion.


PostPosted: Fri Oct 30, 2020 3:58 pm    Post subject: Reply with quote
I can't think of a lens that is different to the standard mount assembly. This is a just acquired 04B 200mm with a loose mount end.



1 = end plate. The 3 screws that hold this are often tight: I use a starret with a removeable JIS 0 head, pair of pliers to get it started.
2 = leaf spring. Note this usually has small fine tune spacer washers under it.
3 = release lever ring.
4 = baffle

Then there is the metal barrel that is the part that rotates, has the f numbers and the ball bearing on the side (at the quarter to position in the pic- L side).

A previous ocasion that I had issues with the operation of the iris (on an 01B 24mm), the problem was the mount of the small wheel (arrowed) had become bent.



In any case it's worth doing the disassembly to check things out.


PostPosted: Wed Jul 14, 2021 2:37 pm    Post subject: Reply with quote
MinniMe wrote:
Yeeahh Smile I found the Mistake. Just screwed the lens open.

The spring ring (sorry for my bad english, I dont know the correct technical term) should be sitting on the disk which moves the pin to secure it from slipping away (seen in picture 2 and 3).
So iI was just moving the Pin, putting the disk back in place and securing it with the spring ring.
The hardest part was placing the spring, making sure the disk was still in place and putting the spring in the right place all at the same time.

I dont know if everything is 100% correct. in picture 4 you can see the aperture when its set to 2.8 and the pin is pressed. I guess the spring was not set correct, but at least the apperture is moving. Maybe someone owning one can confirm if the aperture with 2.8 open and adpter attached is correct this way (what I dont think) or if its not correct.

#3




Hey! I also just came into this lens (after many years of searching) for an alright price. Maybe not so great when you consider my lens also arrived with the aforementioned issue. And out of curiosity, the serial on mine is 900336. Maybe we're just passing around the same bum copy? Or perhaps there is an actual design flaw all of these lenses are experiencing.

So I purchased my copy from a well-known used camera retailer here in the states. It was claimed to be fully functional, but when it arrived, it was missing some parts or a ring on the end of the lens around the front element which retains the hood. So it has no way to attach a filter and the hood just falls off. More critical to the functionality however, is that the aperture was also not functional, it was just stopping down even at f/2.8 when attaching an adaptall mount. I'm very familiar with Adaptall lenses so I recognize this to be incorrect. In my cursory look over the lens, I discovered a "jingle" in the lens, some clanging metal, as well.

Just as you found, MinniMe, I found the spring retaining ring inside was completely loose and the aperture mechanism was dysfunctional. I was able to reassemble things and everything is fully functional as of now. I didn't take any photos at the time of opening things because I hadn't considered doing anything with them at the time. I already cleaned and reassembled the lens so rather than reopen anything, I made a little Photoshop edit to one of your photos MinniMe for further clarification on my understanding of the fix:



1. This pin rides in that irregularly-shaped channel. Make sure, when replacing the rotating ring, you pull this pin out from under the ring, and into this channel. It's tensioned by a spring so it will continually want to 'pop' back under the ring as you attempt to replace the spring retaining ring.
2. The spring retaining ring clicks in neatly just beneath the lip of the inner barrel.
3. There is a notch out of the lip of that inner barrel. Similarly, the spring retaining ring has a shallow notch opposite it's open side. I started by aligning this notch into that cutout of the barrel lip. Then I carefully, using narrow tweazers and my screwdriver, stabilized the ring, and worked my way around it, to get it set in that lip.

Once this was all set, I put the rear optical cell back in place, put the mount back together, and installed the Adaptall mount. So far everything is working. It did appear my lens had been opened before. I am curious if this retaining ring will come loose again and if there is indeed a flaw in the design. It strikes me that the notch in the retaining ring either gets worn down, or was never as prominent as it needs to be to stay in place. And perhaps with use, it rotates, and ends up colliding with that pin, and in turn gets unseated. This is just a guess though.


PostPosted: Thu Jul 15, 2021 10:33 am    Post subject: Reply with quote
I acquired one of these during lockdown, Aperture works as designed and no image shaped baffle at the back,


PostPosted: Thu Jul 15, 2021 2:23 pm    Post subject: Reply with quote
Yes, I meant to mention, the baffle that was being asked about earlier in the thread is simply part of the specific adaptall adapter. I know of at least some Konica and Canon FD adapters that have that square cutout light baffle. But I have never come across a Nikon adaptall mount with the rectangular light baffle. I'm not entirely certain why some have it and others do not. Either way, it isn't part of the lens itself.
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