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Olympus G.Zuiko Auto-W 25mm F/2.8 for Pen F or APS-C
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PostPosted: Thu Aug 18, 2011 5:13 pm    Post subject: Reply with quote

very impressive, beautiful samples!
Pen F lenses are a perfect match for the NEX

uhoh7 wrote:

In the lens tests done in contemporary magazines of the major Pen F lenses, this had the highest resolution of the bunch.

The 20/3.5 was also very good.

2 other famous Pen lenses are the 60/1.5 and 70/2, the latter usually regarded as sharper. However in the same tests the 60/1.5 actually outperformed the 70/2 at similar apertures.


are there any tests of Pen F lenses available online?


PostPosted: Thu Aug 18, 2011 5:23 pm    Post subject: Reply with quote

kuuan wrote:
very impressive, beautiful samples!
IMO the Pen F lenses are the perfect match for the NEX

uhoh7 wrote:

In the lens tests done in contemporary magazines of the major Pen F lenses, this had the highest resolution of the bunch.

The 20/3.5 was also very good.

2 other famous Pen lenses are the 60/1.5 and 70/2, the latter usually regarded as sharper. However in the same tests the 60/1.5 actually outperformed the 70/2 at similar apertures.


are there any tests of Pen F lenses available online?


http://www.skipwilliams.com/olympus/pen-lit/camera35-test-pen-lenses-0170.pdf

From Last nite:





In terms of pure center sharpness, this lens can play with the big boys--it has some really serious resoultion.

Corners are unpredictable--and to get an honest judgement, I'll have to wait for the Nex-7 which has the M9 style offset micro lenses to enhance the corners.

Then we can see what is spherical and what was just my sensor on the nex-5 Smile


PostPosted: Thu Aug 18, 2011 6:46 pm    Post subject: Reply with quote

thank you very much for the link, very interesting!
Unfortunate that the test of the f1.8/38mm is missing, also the one of the f4/25

I am also very curious of the corner sharpness on the NEX7 will be better, reports say and show that on the 3C it is much improved


PostPosted: Thu Aug 18, 2011 9:24 pm    Post subject: Reply with quote

kuuan wrote:
thank you very much for the link, very interesting!
Unfortunate that the test of the f1.8/38mm is missing, also the one of the f4/25

I am also very curious of the corner sharpness on the NEX7 will be better, reports say and show that on the 3C it is much improved


both the 4/25 and the 38/1.8 are supposed to be very good.

the 42/1.2 is a spectacular superspeed, which turns wicked sharp across the frame at f/8.

It is the lightest, smallest fully functioning superspeed that will go on a nex.

@1.2:

the 42 weighs 264 grams Smile


PostPosted: Fri Aug 19, 2011 7:58 am    Post subject: Reply with quote

uhoh7 wrote:
kuuan wrote:
thank you very much for the link, very interesting!
Unfortunate that the test of the f1.8/38mm is missing, also the one of the f4/25

I am also very curious of the corner sharpness on the NEX7 will be better, reports say and show that on the 3C it is much improved


both the 4/25 and the 38/1.8 are supposed to be very good.


thank you very much.
I am very curious how the 1.8/38 compares to the 1.4/40 at shared apertures. very similar then, i suppose

uhoh7 wrote:
the 42/1.2 is a spectacular superspeed, which turns wicked sharp across the frame at f/8.

It is the lightest, smallest fully functioning superspeed that will go on a nex.

@1.2:

the 42 weighs 264 grams Smile


obviously a great lens, quite amazing the wide open shot!
but just like the 1.5/65, 2/70 it is very dear, and so are the wide angel Pen Fs Sad
but you are lucky with great deals for special lenses, I remember you also got the f1.4/50 Nikkor rangefinder "Sonnar" for cheap too, another dream lens that usually sells for big bucks


PostPosted: Fri Aug 19, 2011 6:13 pm    Post subject: Reply with quote

kuuan wrote:

thank you very much.
I am very curious how the 1.8/38 compares to the 1.4/40 at shared apertures. very similar then, i suppose


obviously a great lens, quite amazing the wide open shot!
but just like the 1.5/65, 2/70 it is very dear, and so are the wide angel Pen Fs Sad
but you are lucky with great deals for special lenses, I remember you also got the f1.4/50 Nikkor rangefinder "Sonnar" for cheap too, another dream lens that usually sells for big bucks


As you can see in those tests the 40 is sharper sooner than the 42, but at f/8 the 42 actually beats it!

I have heard the 38 is at least the equal of the 40, but have not had a chance to try.

They are they cheapest, as you know, going for around 130USD Smile

I have a new shot from the nikkor S 50/1.4 I will put up in that thread, which I think gives a good idea of it's unique character Smile


PostPosted: Tue Apr 14, 2015 2:48 am    Post subject: Reply with quote

This thread's been dormant for a while but has been really helpful to me, so I thought I'd share my experience with Pen F lenses. I have several and use them regularly on the Fuji XE2 and Pen FT film bodies. Most of mine have been serviced by John Hermanson at www.zuiko.com, who does fantastic work. Some thoughts:

20mm 3.5: Unfortunately, my copy has a defect with one of inner elements which is quite common, and it flares easily in the presence of any bright light source. However, sharpness and color are excellent, and flare is less noticeable stopped down. I'm still looking for a copy with better glass, which I expect would be a great performer.

25mm 2.8: My most recent find. Slightly prone to flare and bit of glow wide open, nice stopped down. My copy is sharp across the frame by F11, and this focal length is great on APSC cameras.

38mm 3.5 Macro: A remarkable lens. Super sharp and incredibly compact for a macro. Said to be one the sharpest of the Pen F lenses and I can confirm this to be true with my copy.

38mm 1.8: The commonly encountered standard lens. I have 3 of these that came with Pen F and FT bodies that I've purchased. A great lens, especially for the budget-conscious, and this is probably the most affordable Pen F lens. However, I rarely use it because of the next lens on the list...

40mm 1.4: Remarkable. This lens is on my camera 90% of the time, and always in my bag. Incredibly sharp, and I really like the character of this lens. It's often said that the 38mm is the sharper of the two, but I don't find this to be true based on comparing my 2 copies of the 40mm and 3 copies of the 38mm. It's as sharp wide open as my SMC Takumar 50mm 1.4, which is saying a lot. By 2.8, I consider it to be more than acceptably sharp across the entire frame. Out of focus areas have great character. Going rate for a good copy is about $175USD -- based on price to performance, I think this lens is a great value.

42mm 1.2: These lenses often have issues with haze caused by separation in the front element, and clean copies are hard to find. I've read that only about 16,000 copies were made, and I'm lucky to have 2 of them. Remarkable for it's character wide open and sharpness / color stopped down as pervious posters have mentioned. Expensive but worth it. No other 1.2 can do what this lens does in terms of close focus ability and rendering character.

60mm 1.5: I don't own this lens. Good copies turn up infrequently and always seem to be in the $700+USD range. I have number of fast non-Pen 50mm lenses, and haven't been able to justify purchasing this one. I got a Jupiter 3 50mm 1.5 for 1/3rd the price, which is super compact and fabulous to use on the XE2. I hope to own the 60mm lens someday if I can find one cheap, but for now it's strictly wish list material.

100mm 3.5: My copy has perfect glass but flares like crazy, even with a nice deep lens hood. I find this lens to be physically longish, and I have other lenses in the 100-105mm range of the same vintage that I use more. A great lens to be sure, but there's a number of excellent and compact 2.8 T-mount lenses in the same focal length range with 10+ aperture blades that I prefer over this lens.

Pen F lenses are excellent, but I think it's difficult to find good copies. The variability of user reports on the web seems to confirm this. Without carefully inspecting the glass, especially internal elements, it's hard to know if you have a clean copy that will perform well. Lens hoods are also an absolute must to get good performance from Pen F lenses. I'll try to post some images soon from each lens.


PostPosted: Tue Apr 14, 2015 3:58 am    Post subject: Reply with quote

great write up John and I agree with everything you say, some minor points though:

-the 20mm is prone to have a certain fault, me too I had to get a second copy to get a good one, and it was worth it!
- me too I have been using the 1.4/40 most, but I recommend to not discard the 38 for it. The 1.8/38 has lively bokeh that is very particular which makes it a more unusual and very fun, imo for some situation the better lens.
- Chance to get a faulty copy sure is higher than when buying a Takumar, but I do not find it all that difficult to find good copies neither. I have bought 20 to 25 Pen-F lenses ( resold quite a number ) and it was only one copy of the 20mm that had it's typical fault ( which I was able to repair to 'almost' bring it back to normal ) and a copy of the 2.8/25 that had faulty rear lens that made it bloom. All others were optically quite ok, a few had minor coating defect but to an extent that didn't impact performance in any noticeable way. Having said that I recommend to also look for mechanical condition, build quality is not all that strong. Aperture ring could be clunky, fixable but it's assembly is quite delicate, one had a stuck focus ring that was repairable but it wasn't easy, really.
- your 3.5/100 seems to be faulty, I haven't noticed strong flare on 5+ copies that I have had

- you are in luck about the f1.5/60mm! see this offer here in this very forum:
http://forum.mflenses.com/olympus-g-zuiko-auto-t-11-5-60mm-lens-for-pen-ft-camera-t70659.html
great price ( I paid more for mine by now a few years back in Japan ) and that from a very reputable member and seller here!


Last edited by kuuan on Tue Apr 14, 2015 4:50 am; edited 2 times in total


PostPosted: Tue Apr 14, 2015 4:10 am    Post subject: Reply with quote

Interesting list and comments John + Andreas. I haven't had issues so far with my set. I basically have the same list;
I don't have the f1.2/42mm, but the f2/70mm and the f1.5/60mm, the latter being a fantastic lens.

Here my Albums using a few of those lenses:

- f1.5/60mm: https://www.flickr.com/photos/kds315/sets/72157636354848163/
- f2/70mm: https://www.flickr.com/photos/kds315/sets/72157636244625685/
- f3.5/38mm: https://www.flickr.com/photos/kds315/sets/72157635275921147/
- f3.5/20mm: https://www.flickr.com/photos/kds315/sets/72157628444467231/


PostPosted: Tue Apr 14, 2015 4:48 am    Post subject: Reply with quote

the 38mm Macro, the 1.2/42 and 70mm I don't have, so I can offer links to pics taken with:

- the 'faulty', later repaired 3.5/20: https://www.flickr.com/photos/kuuan/sets/72157628125919493/ ( the photos taken after repair appearing first )
- good copy 3.5/20: https://www.flickr.com/photos/kuuan/sets/72157647002683101/
- faulty 2.8/25: https://www.flickr.com/photos/kuuan/sets/72157629419646160/ ( for sale, see my sig )
- 2.8/25: https://www.flickr.com/photos/kuuan/sets/72157647206708242/
- 4/25: https://www.flickr.com/photos/kuuan/sets/72157629897212327/
- 1.8/38: https://www.flickr.com/photos/kuuan/sets/72157627988053181/
- 1.4/40: https://www.flickr.com/photos/kuuan/sets/72157629315399105/
- 1.5/60: https://www.flickr.com/photos/kuuan/sets/72157631525848244/
- 3.5/100: https://www.flickr.com/photos/kuuan/sets/72157628364071135/


PostPosted: Sat Apr 18, 2015 5:03 pm    Post subject: Reply with quote

Great to see some activity on this thread again! I really love using my Pen F lenses and appreciate this conversation and the sample images.

Question about the experience others have had with the 25 2.8: how is the performance wide open? I just got one and I'm trying to figure out if the slight glow I'm getting wide open is true to what others have experienced. The glass has a very slight haze in the rear element, however, it is very slight, indeed -- not at all like my 20mm 3.5, which is downright cloudy and blooms excessively in any bright light. I'll try to post some example pix later today.


PostPosted: Sun Apr 19, 2015 4:19 am    Post subject: Reply with quote

johnnyjr wrote:
Great to see some activity on this thread again! I really love using my Pen F lenses and appreciate this conversation and the sample images.

Question about the experience others have had with the 25 2.8: how is the performance wide open? I just got one and I'm trying to figure out if the slight glow I'm getting wide open is true to what others have experienced. The glass has a very slight haze in the rear element, however, it is very slight, indeed -- not at all like my 20mm 3.5, which is downright cloudy and blooms excessively in any bright light. I'll try to post some example pix later today.


as mentioned I have two copies of this lens. the first one has coating damage to the rear glass over about a third of it's surface, otherwise it is very clean. As I described in my signature 'lenses for sale' it exhibits 'light bleeding' from an area of strong light into adjoining, very dark area, specially if separated by a distinctive line, and possible blooming at wide apertures. As one can see in the link provided, and I may add some samples below, it still takes great pictures. Great sharpness until corners, lovely colors and tones.
In fact I like them that much that when I found a clean copy for an acceptable price I got it too. This clean copy seems to exhibits similar 'faults' or rather characteristics but to a lesser degree: Contrast loss along a line between strong light and a dark area, possibly some blooming wide open. If and how blooming there is wide open I can't say for sure now, I do not have the lenses with me but I plan to do some wide open test shots when I do.

the 'faulty' copy, mostly it's fine, very fine, two wide open pics




here contrast loss along very bright to darker areas left top corner


wide open in worst case scenario, powerful floodlights


the clean copy with which I may not have taken any wide open shot yet:


I am quite sure that on this last one I did 'contrast repair' in post along the line to the strong sunlight, it was just about noon on a very bright, sunny day in a tropical land:



referring to your 3.5/20: when you look at the lens from the front, it the outer rim, almost half of the glass pitch black? It should be, it's a black paint right on the outer ring of an optical element. This paint can kind of 'evaporate' and manifest itself as many small bubbles covering the whole element. The disappeared paint from where it should be will lead to inner reflections which make it 'bloom', the small bubbles 'might' be the cloudiness that you describe. In that case there is big chance that your lens can be quite effectively be repaired. ( as I did to one copy that exhibited this very problem, I have seen a few for sale that seemed to have exactly the same problem.)


PostPosted: Mon Apr 20, 2015 2:52 am    Post subject: Reply with quote

Thank you for the additional details and sample images, kuuan. My 3.5/20mm has bubbles in the black paint and also internal haze on one of the center elements, so exhibits light blooming very similar to your 2.8/25mm with bright light in the frame. I'm still looking for a 'clean' copy but every lens I come across seems to have the same internal haze. John Hermanson at zuiko.com serviced my 3.5/20mm, and said that both faults were common and non-repairable.

I'm very pleased so far with results from my 2.8/25mm. It does not seem to be exhibiting very much flare/light blooming, but I'm wondering if my copy is quite as sharp as your wide open. There seems to be a big jump in sharpness between f/2.8 and f/4, and I'd be interested in your opinion of the performance of this lens.

Here's some samples:

f/2.8


f/2.8 100% crop


f/4


f/4 100% crop


f/2.8


f/2.8 100% crop


f/2.8


f/8


f/2.8


f/2.8 100% crop


f/11


f/8


f/2.8


f/8


f/2.8


f/2.8 100% crop


f/5.6


f/5.6 100% crop


PostPosted: Mon Apr 20, 2015 4:37 am    Post subject: Reply with quote

Hi John,

your samples look perfect to me. I don't really perceive the jump in sharpness from f2.8 to f4, just more dof, naturally, it looks sharp from wide open to me. Again I am very impressed by the colors, lovely!
I was surprised how big of an area of the full frame your 100% crops are showing. Which camera are you using?
( btw. sorry that my samples cannot be seen in full resolution directly here. I have had troubles to upload here, also to use the BBCode which would link directly to flickr from where one could go to see full res. To see full res. please visit the album linked earlier and choose to photo from there )

Surprising also that your Zuiko repair man says that it is impossible to repair the 20mm. At least the bubbles most likely are just a matter of wiping them off, at least that was the case with my copy
Do you own a lens spanner? Once I had given detailed instructions with photos on how to open to repair the common faults on the 20mm via personal email. Opening it is very easy, if you wanted, or anybody, I shall add those here or send them to you privately, whichever.


PostPosted: Mon Apr 20, 2015 6:03 am    Post subject: Reply with quote

kuuan wrote:
Surprising also that your Zuiko repair man says that it is impossible to repair the 20mm. At least the bubbles most likely are just a matter of wiping them off, at least that was the case with my copy
Do you own a lens spanner? Once I had given detailed instructions with photos on how to open to repair the common faults on the 20mm via personal email. Opening it is very easy, if you wanted, or anybody, I shall add those here or send them to you privately, whichever.


I am with Andreas on this. It may not be repairable to the same standard as new factory-made lens, but I also had one of these lenses, and "repaired" it myself so that it was almost indistinguishable from the other copy of the same lens that does not have this issue.


PostPosted: Mon Apr 20, 2015 11:38 pm    Post subject: Reply with quote

Thanks for your assessment of the lens, kuuan and Alex H. This 25mm definitely falls into the “sharp wide open” book for me, as do all of the other Pen F lenses I have. Even the 1.2/42mm has quite acceptable center sharpness wide open. It’s subjective of course, but I’m happy with the results with the 25mm.

I do see quite a jump in center sharpness with the 25mm from 2.8 - 4, but as you’ve said the biggest difference is increased depth of field. I don’t find this lens to be truly sharp across the entire frame till about f/11, but soft edges and vignetting are plusses as far as I’m concerned. I love these lenses for their character and I’m not seeking clinical sharpness and perfection, just looking for peace of mind that they are solid copies and performing well.

All photos I posted are from the Fuji XE2. I resized the full frames to 1600px wide, then zoomed in to 100% magnification to make the crops — hopefully I did that right. Uploading was a bit wonky.

Kuuan, I have a lens spanner and would be grateful for directions to re-black the front element — please share!


PostPosted: Tue Apr 21, 2015 2:44 am    Post subject: Reply with quote

Hi John,

yes, I also consider my Pen-F lenses to be sharp from wide open. Actually I also find their corner sharpness very impressive, though more of the longer lenses of the 2.8/25 too.

for 100% crops don't resize first but make a crop from the full, original resolution

ok, here you go for the 20mm.
( don't be irritated by the different looking mount of mine, with the bronze part. I had converted all my Pen-F lenses to Leica M mount, so that I can use them on my Ricoh GXR M.
As nice side effect I get even closer focus when used with my Leica M to Sony E helicoid adapter. Conversion is easily fully reversible )

first 2 photos are self explanatory, unscrew the name plate:




once the name plate becomes loose a total of 4 rings will come off.
The last one has the small ball that makes the aperture clicks sitting on a spring.
Be careful not to loose it, best work on top of a tray.



next screw off the full front lens group using the notches circled red ( the yellow ones would unscrew the single front element )





the full front group taken off will look like this, from top / side



from behind



take apart that group. again use the notches circled in red, not the yellow ones




leaving the two groups seen below. most likely only the rear lens of the bigger part seen to the left will be effected ( possibly both )
The paint around the outer rim of the lens element(s) might be partly gone and bubbles covering the inner part of the lens(es).
( not here, the lens seen doesn't have the faults )

The bubbles most likely simply can be wiped of, best use lens cleaning materials.
The outer rims of both lens elements, pointed out in green, must be painted black! Because remnants of the original paint might still 'evaporate' best to first remove the old paint completely
If not confident with the new paint leave what's left of the old and be prepared to possibly, at some point later, having to clean off 'bubbles' and to repaint again



which paint to use was discussed here: http://forum.mflenses.com/which-black-paint-to-use-on-lens-element-t51079.html
( oh, there already I had shown some of the photos how to open this lens but all disappeared. Should try to recover them )

assembly is simply reversing all the steps.
putting the front rings on should be self explanatory, each ring has a notch that puts it into place on the ring below.
The first ring with the ball fits as seen below ( in the photo the ball had fallen off it's spring, of course it must be put on top it first )



If you put on the first ring with the ball in correct position turning it already should open / close the aperture.
Either close it completely or open it completely to f3.5, this will help to put the next ring on in correct position, the ball going in a 'first' hole of this ring.
once the first 3 rings are in place pressure them lightly for the ball to stay in place and screw on the name ring.

that might be helpful too, see the lens scheme here: http://olypedia.de/G_Zuiko_Auto-W_3%2C5/20

cheers, andreas


PostPosted: Wed Apr 22, 2015 3:36 am    Post subject: Reply with quote

Kuuan, thank you for the service guide for the 20/3.5, this is incredibly helpful. Very interested in giving this repair a shot to see if my copy improves. Just looking again at copies of this lens available on ebay and it seems that +80% have foggy glass. The few that don't are over $350USD. Perhaps just as well, I'm happily getting my super wide fix with the tiny and wonderful Voigtlander 15/4.5 these days... still, the colors are so nice out of the 20/3.5 and I'd love to have a top performing copy.


PostPosted: Wed Apr 22, 2015 7:10 am    Post subject: Reply with quote

Very good samples!!


PostPosted: Thu Apr 23, 2015 4:33 am    Post subject: Reply with quote

I have this pen-zuiko 20/3.5, but there is a lot of fog inside the lens - do you think it´s possible to clean?


PostPosted: Thu Apr 23, 2015 6:26 am    Post subject: Reply with quote

donald dump wrote:
I have this pen-zuiko 20/3.5, but there is a lot of fog inside the lens - do you think it´s possible to clean?


Andreas (kuuan) has just described that.... Wink


PostPosted: Thu Apr 23, 2015 6:55 am    Post subject: Reply with quote

kds315* wrote:
donald dump wrote:
I have this pen-zuiko 20/3.5, but there is a lot of fog inside the lens - do you think it´s possible to clean?


Andreas (kuuan) has just described that.... Wink


yes, but I liked to know if you have experience that you get the fog normally cleaned out or are the foggy lenses spoiled nonuseable...


PostPosted: Thu Apr 23, 2015 7:27 am    Post subject: Reply with quote

welcome Johnny. I wish you much success to improve the performance of the lens. It's colors and looks definitely are lovely, different than that of e.g. the rather modern CV 4/21 which is a great lens in it's own right too. As you can see it's not difficult to open, go for it Wink

Donald there is no way to know for sure, but in the case of the Pen-F 20mm I'd say that the probability that it can be cleaned very easily is very high ( unlike the 'etching' on an inner element of typically some Canon LTM lenses, namely black 1.8/50 and 3.5/100, or also the M-Rokkor 2.8/28 )