[pacerr]

On the 04B, when you look down into the lens from the front you can see a small line about 3mm long on what looks like the second element in from the top.

Its not on the outer edge of the lens near the barrel. Its not directly in the center either.

---------- Post added 03-10-15 at 09:25 AM ----------
the element

I can't imagine a "crack" that doesn't originate at the edge of an optical element.

[vonBaloney]

---------- Post added 03-10-15 at 09:25 AM ----------
the element

I can't imagine a "crack" that doesn't originate at the edge of an optical element.

Yeah, don't think that can be a crack, not internally. I'm not sure I've ever seen any lens "crack". Much more likely fungus or even a reflection (they can fool you with looking through multiple elements)...

[tim60]

I have an Adaptall2 28-50 with 58mm filter mount. I bought it new in November 1980. I could not find a review of it in PF. I search on eBay a couple of times for it but got no hits.


Does anyone know anything about it?

[vonBaloney]

I have an Adaptall2 28-50 with 58mm filter mount. I bought it new in November 1980. I could not find a review of it in PF. I search on eBay a couple of times for it but got no hits.


Does anyone know anything about it?

The 07A?

Tamron Adaptall-2 28-50mm f/3.5-4.5 (07A) Lens Reviews - Tamron Adaptall Lenses - Pentax Lens Review Database

Tamron Adaptall-2 28-50mm F/3.5-4.5 Model 07A

[tim60]

The 07A?

Tamron Adaptall-2 28-50mm f/3.5-4.5 (07A) Lens Reviews - Tamron Adaptall Lenses - Pentax Lens Review Database

Tamron Adaptall-2 28-50mm F/3.5-4.5 Model 07A

Thanks. That looks like it. Must have searched the reviews badly.


I felt disappointed by the lens although I did also get some good frames with it in both B&W and Kodachrome. It is a while since I have gotten it out. Also, I took it to the race track at Maree for a car event just before Christmas 1980 and it got dust into the zoom ring which spoiled the feel and made it impossible to get zoom to either extreme. That is damage, not the manufacturer's fault.

[vonBaloney]

Thanks. That looks like it. Must have searched the reviews badly.


I felt disappointed by the lens although I did also get some good frames with it in both B&W and Kodachrome. It is a while since I have gotten it out. Also, I took it to the race track at Maree for a car event just before Christmas 1980 and it got dust into the zoom ring which spoiled the feel and made it impossible to get zoom to either extreme. That is damage, not the manufacturer's fault.

I wouldn't expect too much of the non-SP Adaptalls, but they probably vary, and I haven't tried any of the pre-AD2 models at all. The whole line is prone to purple fringing and green/magenta bokeh, but the the SP lenses are sharp as hell when you nail focus, and the aberrations are mostly correctable in processing.

[52b]

Yeah, don't think that can be a crack, not internally. I'm not sure I've ever seen any lens "crack". Much more likely fungus or even a reflection (they can fool you with looking through multiple elements)...

Interesting so maybe its the start of fungus or some other material that's stuck to the lens?

I'll tried to take a picture of it with my phone didn't show the crack. I'll have to try again to get a better picture.

[vonBaloney]

Interesting so maybe its the start of fungus or some other material that's stuck to the lens?

Sometimes fungus grows as whitish dots -- those are pretty obvious. Other times it is a VERY fine spider web type thing and can be pretty hard to see. That could look like a crack. You want to clean that if possible...

[52b]

Ok so I was wrong about the 02B. Turns out was some type of debris that was stuck to the third element from the rear. I removed the elements from the rear, cleaned them and now it seems cleared up. I hadn't used the lens in about a year because of the dot that kept showing up in all my shots. Seems to be good now.

The 04B there is still an issue. Maybe its just a fiber? Seems to have a yellowish color. See the line thats circled in red.

[pacerr]

Removing the rear element group may be easy in many cases but it can cause focusing problems it isn't re-assembled properly. A little tweaking can fix it but it can be time consuming if you don't have test bench tools and charts.

It pays to scribe an index (witness) mark near any threads to aid in re-assembly. Especially when you remember to do so BEFORE you initially remove an element!

I've acquired a few problematic lenses that only needed properly seating or adjusting the rear element to recover from a lack of focus / sharpness.

[marcusBMG]

Maybe its just a fiber? Seems to have a yellowish color. See the line thats circled in red.

mmm something like that, always a bit of a mystery as to how it might get in but I have had lenses with similar things, and even dead dust mites though they can move and grow. If its bugging you then its not difficult to remove the front element with a lens spanner and brush/blow it away, however since this will not affect your pics I suggest just ignoring it.. (some perspective here ).

[vonBaloney]

I had an old Takumar that had an embedded mosquito in it. I swear it was IN the glass. Looked like the sap sample they got the dinosaur DNA from in Jurassic Park...

[52b]

Removing the rear element group may be easy in many cases but it can cause focusing problems it isn't re-assembled properly. A little tweaking can fix it but it can be time consuming if you don't have test bench tools and charts.

It pays to scribe an index (witness) mark near any threads to aid in re-assembly. Especially when you remember to do so BEFORE you initially remove an element!

I've acquired a few problematic lenses that only needed properly seating or adjusting the rear element to recover from a lack of focus / sharpness.

Pacerr,

It seems the 02B and 04B's rear elements can be easily removed / reinstalled. Can you explain what exactly you mean by index (witness marks). After I removed the elements and re-installed them the lens seems to focus and be just as sharp as before.

I made sure all the elements where securely in place and the spacer rings were properly in place.

---------- Post added 03-13-15 at 11:55 AM ----------

mmm something like that, always a bit of a mystery as to how it might get in but I have had lenses with similar things, and even dead dust mites though they can move and grow. If its bugging you then its not difficult to remove the front element with a lens spanner and brush/blow it away, however since this will not affect your pics I suggest just ignoring it.. (some perspective here ).

So it turned out to be some sort of debris stuck to the back side of the third inner front element on the 04B. I removed the two rear elements from my 04B and used my rocket blower to blow air into the barrel from the rear. That seem cleared it up.

Now my 04B and 02B are back in business!

[marcusBMG]

So it turned out to be some sort of debris stuck to the back side of the third inner front element on the 04B. I removed the two rear elements from my 04B and used my rocket blower to blow air into the barrel from the rear. That seem cleared it up.

Good effort! So looking at my 04B I take it the rear elements unscrewed as a unit?

[52b]

Good effort! So looking at my 04B I take it the rear elements unscrewed as a unit?

Doesn't unscrew as a unit. There is a end piece that holder the rear element in place that screws into the focusing barrel. The second rear element is held in in place with another space. Once the spacer and second element was removed I could get the blower in to blow out the rear side of the front elements