RE Auto Topcor 20mm f4

Macca · Joined: 20 Mar 2012 Posts: 248 Location: Glasgow, Scotland.

A few from this old rarity.Processing may be iffy as I`m working of an old laptop for the past few months due to house renovations and it`s not ideal, so minimal pp mostly.
First shot on a dull day

Some indoor museum type shots,highish iso.
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High contrast day- beach type.
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refelction in bottom right corner caused by lens hood/polariser.
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A couple of Topcor "blue sky" shots.
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Both shot with series 9 linear polariser. All on A7 mk 2.

scsambrook · Expire: 2011-11-18

Well, they look nice on my screen - quite an uncommon lens.

cyrano · Expire: 2016-12-30

That looks to do the job! Is it that rare a lens?

Macca · Joined: 20 Mar 2012 Posts: 248 Location: Glasgow, Scotland.

According to Antonetto and known existing serial numbers no more than 1800-2000 were ever made.

calvin83 · Joined: 12 Apr 2009 Posts: 7553 Location: Hong Kong

I have this lens and it perform pretty good on my 5N. It is good to see it perform pretty well on an A72 too.

vroger · Expire: 2016-10-21

Thanks for sharing.

Lightshow · Joined: 04 Nov 2011 Posts: 3669 Location: Calgary

Very nice.

Macca · Joined: 20 Mar 2012 Posts: 248 Location: Glasgow, Scotland.

Thanks folks, these first ones were in more challenging conditions I guess and I`m still getting used to the A7mk2 and lens combo as it`s wider than I usually shoot! Here`s some more recent shots, it really is a fine little lens, not as soft in the corners as as I`ve read.

Topcor wides usually tolerate being stopped down to f13-16 without any great loss through diffraction, not a huge amount of distortion either so looking forward to using it more over the coming months.

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IAZA · Joined: 16 Apr 2010 Posts: 2587 Location: Indonesia

nice samples.
I have this lens too. Many people said, it has better sharpness compared to Flektogon 20/4. I agree with it. specially wide open.

Macca · Joined: 20 Mar 2012 Posts: 248 Location: Glasgow, Scotland.

Thanks IAZA, nice to know.Strangely enough apart from the couple of days I`ve had out with it I haven`t really used it wide open or close up yet so will when I get the chance!

stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

I recently found one of these little rare RE 4/20 mm beasts, together with the classical RE 1.8/5.8 cm and the RE 2.8/10 cm. Since i don't have an adapter yet, i didn't use it on the A7II. Together with the RE 1.4/5.8cm and the RE 3.5/135mm and two (slightly different) Topcon RE super SLRs they make a small but nice collection.

Which adapter do you use on the Sony A7II?

Stephan

Lightshow · Joined: 04 Nov 2011 Posts: 3669 Location: Calgary

I'm using a Big_is adapter, it's ok, my only nitpick is the release lever doesn't stick out very far, it's almost flush with the body of the lens, that may be a good thing depending on how you look at it.

stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

Here are a few images taken today here in my hometown Luzern (Lucerne in English). The light was peculiar - some very slight fog / mist, and very dim sunlight "shining" through the overcast. All pictures taken with Topcor RE 4/20mm and Sony A7II in "autumn mode" (to enhance colors, especially the yellows & reds).

PLEASE CLICK ON THE IMAGES TO GET ORIGINAL COLORS - FOR REASONS UNKNOWN TO ME SOME OF THE "THUMBNAILS" SHOWN BELOW HAVE PRETTY DULL COLORS ... !

Kasernenplatz in Lucerne, with the Science Museum on the left and the Historical Museum in the middle.
Topcor RE 4/20mm @ f11. JPG out of Sony A7II, "autumn mode".

Small venue near the Kasernenplatz, with parts of the building of the "Luzerner Staatsarchiv" (state archives) on the right.
Topcor RE 4/20mm @ f11. JPG out of Sony A7II, "autumn mode".

Display window of the "Alte Suidtersche Apotheke", the oldest pharmacy in Lucerne.
Topcor RE 4/20mm @ f11. JPG out of Sony A7II

Ancient houses near the Pilatusplatz. Some building in this street date back to the 15th century.
Topcor RE 4/20mm @ f4 (wide open). JPG out of Sony A7II, "autumn mode".

View from the Jesuitenkirche over the Reuss river. Large renaissance style building with tower on the left side is the Rathaus (city hall), built 1602-1606 partly in Italian style (facade) and partly in local style (roof). On the right side the Wasserturm ("water tower") which probably dates back to 1300.
Topcor RE 4/20mm @ f11. JPG out of Sony A7II, "autumn mode".

Back side of the main building of the "Luzerner Kantonalbank" (state bank of Lucerne), built around 1973.
Topcor RE 4/20mm @ f11. JPG out of Sony A7II, "autumn mode".

Detail of a zebra crossing and pavement just behind the "Kantonalbank".
Topcor RE 4/20mm @ f11. JPG out of Sony A7II, "autumn mode".

Ancient buildings adjacent to the Reuss river, partly dating back to the 16th century.
Topcor RE 4/20mm @ f11. JPG out of Sony A7II, "autumn mode".

Picture taken at the same location as above, but in the other direction: The Reuss river and the regulation system for adjusting its flow and for regulating the level of Lake Lucerne ("Vierwaldstättersee").
Topcor RE 4/20mm @ f11. JPG out of Sony A7II, "autumn mode".

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stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

Compared to other well respected "slow" and small superides, the Topcor RE perfoms very well, especially at f11. I am pretty impressed by the lacking CAs and the very good corners. Actually this lens, at f11, might be nearly as good as the Loxia 21mm!

First the overview and the crop area (yellow):

Now the 100% crops from JPGs out of the 24 MP Sony A7II.
CLICK TWICE ON THE IMAGE TO GET FULL RESOLUTION!

I have tested also the Konica AR 4/21mm (with 77mm filter diameter certainly not a small lens), and it is not as good as the Topcor, but better than the Olympus.

Maybe that's useful for those who look for a smallish 20mm "landscape" lens with a very good performance at f8 or f11.

S

cbass · Joined: 27 Jul 2019 Posts: 441

These old top whores can really surprise you.

kds315* · Expire: 2021-03-09

I have it, too

Lightshow · Joined: 04 Nov 2011 Posts: 3669 Location: Calgary

stevemark · Joined: 29 Apr 2011 Posts: 3754 Location: Switzerland

The achilles heel of the Topcor RE 4/20mm is its strong and complex distortion:

Those lines at the border should be straight. They are not.

Image taken at the Rittersaâl of the episcopal castle of Chur / Switzerland.

S

D1N0 · Joined: 07 Aug 2012 Posts: 2491

Much like the Pentax-m 20/4. I looked up the diagrams to see if they might be the same. Not really
left Pentax, right topcor

Well at least no change of separation problems with the Pentax

John Shriver · Joined: 24 Dec 2009 Posts: 192

I've never had element separation on any Topcor lens, and I have all the R. Topcor and RE. Auto-Topcor lenses.

I have had element separation in the Pentax 100/4 short-mount K-mount macro lens, and on a Leica Summar 50/2.0. Former was fixed by Eric Hendrickson, and I baked the Summar doublet in the oven (it also had a cracked element).

BrianSVP · Joined: 09 Jun 2023 Posts: 294 Location: Philadelphia

I've recemented an RE 58mm f/1.4 that had yellow edge separation in both doublets. Original cement was Canada balsam, which I replaced with Norland UV cure lens adhesive.

The Pentax 100 macro uses an early form of UV cure epoxy and almost always ends up with hazy separation. The SMC-K 50mm f/1.4 also tends to this problem. Whereas the topcor only required an acetone bath to separate, the Pentaxes require Methylene Chloride, or if you can't find it, you can place the doublet on top of a cold 100w bulb, then turn it on, which heats it gently enough to separate the crown and flint without cracking them. Just make sure you monitor it carefully and turn the bulb off as soon as the cement has separated, so it doesn't get too soft, allowing the top element to slide off onto the floor.

ZuikosHexanonsandVivitars · Joined: 03 Nov 2021 Posts: 223 Location: Austria