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Isco Gottingen Westrocolor 1.9/50 - aperture fixed - Samples
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PostPosted: Fri Mar 27, 2015 7:56 am    Post subject: Isco Gottingen Westrocolor 1.9/50 - aperture fixed - Samples Reply with quote

Is there some trick to getting the aperture blades to engage on this lens. It is in Exakta mount with the large silver button on the top side.
The aperture ring rotates nicely and makes lovely smooth clicks - but alas no closing of aperture takes place.
Your thoughts are welcome.
So currently it only shoots wide open.
Here is the lens followed by some samples at f1.9
Cheers
OH









Last edited by Oldhand on Wed Apr 01, 2015 8:57 pm; edited 1 time in total


PostPosted: Fri Mar 27, 2015 8:37 am    Post subject: Reply with quote

The aperture closes when you push the button on the lens. If it doesn't close down, you need to open it up to see what's wrong.


PostPosted: Fri Mar 27, 2015 8:52 am    Post subject: Reply with quote

Rawit wrote:
The aperture closes when you push the button on the lens. If it doesn't close down, you need to open it up to see what's wrong.


Thank you Rawit - yes that is what I thought happens - but pressing the button has no effect at any aperture.
How difficult is this lens to repair?
OH


PostPosted: Fri Mar 27, 2015 8:57 am    Post subject: Reply with quote

It's hard to say... I fixed a couple of Domiplans a few years back, only to find out I had 3 different versions with 2 different button configurations. I would start with looking up some guides if available or try to remove the button from the lens to see if what's up with the spring/mechanism. A smooth clicking aperture ring makes me think the problem is with the button.


PostPosted: Fri Mar 27, 2015 9:40 am    Post subject: Reply with quote

A nice clicking ring is very well possible when rhe aperture blades are sticking in WO position as they have become smeared by oil from the mechanism. Probably you have te clean the blades. In most Exakta lenses (not the Domiplan) the outside button construction is rather solid; space enough for that!
Your nice pictures proof IMHO rhat the lens is worth the effort


PostPosted: Fri Mar 27, 2015 10:16 am    Post subject: Reply with quote

Does the large silver button turn like a screw to open and screw to close, then it opens and closes the aperture?


PostPosted: Fri Mar 27, 2015 10:59 am    Post subject: Reply with quote

You are right Mo, I forgot that the release and aperture can be blocked by turning the knob of most of these lenses Embarassed
That would be the easiest solution, just by turning that button.


PostPosted: Fri Mar 27, 2015 11:45 am    Post subject: Reply with quote

Thank you both for your replies.
Yes, the knob when depressed acts like a cam which activates a lever which should close the aperture.
If the knob is rotated when depressed, it closes the aperture and keeps it closed at whatever f stop is chosen in the aperture ring.
Sadly on mine - nothing happens within the lens even though the knob and lever are working.
Perhaps there is a missing linkage inside the lens or the aperture blades are stuck.
Cheers
OH


PostPosted: Fri Mar 27, 2015 6:48 pm    Post subject: Reply with quote

Likely needs to be cleaned, good luck.


PostPosted: Sun Mar 29, 2015 9:04 am    Post subject: Reply with quote

Lightshow wrote:
Likely needs to be cleaned, good luck.


Yep, either that or a linkage is unattached.
Here are a couple of quickies from this afternoon - wide open of course.
OH




PostPosted: Sun Mar 29, 2015 4:18 pm    Post subject: Reply with quote

Very nice Tom, that is a good lens. Another little job for your son. He needs the practice anyway. Certainly worth the effort.

Regards,

Gavin


PostPosted: Mon Mar 30, 2015 10:26 am    Post subject: Reply with quote

If he lets me in there after my failure with a certain 57mm 1.4 of mine. Hmmmmm...??
A learning experience, none the less.
Very nice shots oldmate by the way Smile


PostPosted: Wed Apr 01, 2015 1:09 am    Post subject: Reply with quote

My amazing son - BeardsAreBest - has taken my Isco Gottingen Westrocolor and repaired the aperture mechanism for me.
It not only shoots wide open, but now has a usable set of aperture stops.



I immediately took it outside to give it a burl.
Here are some quick images from f/1.9 through to f/16.
There is an increase in acuity from f/1.9 through to f/8, with diffraction kicking in at f/16
Again - no PP except change from RAW to .jpeg
So - here we go:

@f/1.9




@ f/4




@f/8



@f/16 and diffraction is starting to soften the image a little



I can't help thinking of the often repeated statement that Isco were second quality Schneiders.
I see nothing but quality here.
Cheers
OH


PostPosted: Wed Apr 01, 2015 3:19 am    Post subject: Reply with quote

And here is the lens sporting its newly activated and cleaned aperture blades.
OH



PostPosted: Wed Apr 01, 2015 4:04 pm    Post subject: Reply with quote

Congrats with the working lens and with a son that handy!


PostPosted: Wed Apr 01, 2015 8:48 pm    Post subject: Reply with quote

The definition in images continues to surprise me with this wonderful lens.
OH

taken at f/4



Crop of above:



PostPosted: Wed Apr 01, 2015 9:12 pm    Post subject: Reply with quote

Image quality is above average, I wish more lenses were this good.


PostPosted: Wed Apr 01, 2015 10:22 pm    Post subject: Reply with quote

Nice results indeed. I have this lens to, but different visual design. I would still guess that the lens design is equal.



PostPosted: Wed Apr 01, 2015 10:35 pm    Post subject: Reply with quote

Thank you both.
I think that your lens looks prettier than mine Nordentro Very Happy
I hope that your results are as good as I am getting (not boasting - just enormously happy with them)
OH