"U would be an idiot not to have such a lens", you got me. I bought it. Subscribed.

Finally an honest review, depitching the defect other then presenting it as the "perfect bargain"

Usually it's pretty pointless to watch reviews of stuff you just bought, but this time definitely with it! Thanks for the focus breathing tip! Can't wait to get mine tomorrow!

Great review - a brilliant combination of real world comments and technical info. Thank you!

Thank you very much for your review. I just bought this lens and use it on a Lumix G100. The focus shift is visible exactly according to your analysis at f 2.8, f 4 and f 5.6. But for me the recommendation to go into manual mode to avoid focus shift, seems a little bit complicated in practical use. I see two more simple solutions: (1) When taking the picture set the focus point a little bit behind the desired object, 1.5 to 2 % at f 2.8/5.6 an 3 - 4 % at f 4.0. (2) With Function Buttom Fn6 (can easily be moved to Fn4) you can set the camera in the "Preview Mode", which (for one single shot ) is used "to check the effects of aperture on the recording screen by physically closing the aperture blades of the lens to the value set for actual recording". This works in all modes and you don't have to switsch to manual mode. I tried it with the G100 and it it worked well.

wonderful review! thank you for the effort and the sharing. i understand the concept behind the problem of focus shifting. i am not quite sure how to alter my shooting technique to correct the situation. i will look at your other vid on focus shift and hopefully i will understand the proper technique. thumbs up.

Great video and commentary as always. Thank you for your honest, deeply appreciated.

Jump to chapters! Intro 0:00 Build quality/handling 0:43 Auto focus 2:20 Sharpness/focus shift 2:27 How to avoid focus shift 5:26 Focus breathing 6:59 Chromatic aberrations 7:10 Geometry 7:34 Coma 7:45 Vignetting 7:55 Flare 8:07 Bokeh 8:47 Macro 9:10 Starburst 9:30 Conclusion 9:40

Thanks for the details! Good review

Good video. Very detailed breakdown of this lens. Great information.

I just got this lens and I love your accent.

Hey what lens do you think that's good for videos. I want one that's better than the one that come with Panasonic G7. I want it to have good auto focus and stabilization. Thanks for your help

This is an awesome review, thanks!

If I could only keep one lens to use I would choose this one. Great review!

Very good test. Thank you.

Good review, thank you!

Excellent. Thank you.

Great job! I have and enjoy this lens.

Exellent review and goos sense of humor.

Great review - I've had this lens for a while but never knew about the focus shift issue. I shoot an Olympus E-M10 so now I need to find how to get it to close the aperture in preview and focus before firing the shutter. Thanks!

Nice review. I would love to see you do a comparison of this lens with the Olympus 1.2 (which is so much more expensive, not to mention significantly bigger and heavier. ) For that matter, you could throw the Olympus 25mm 1.8. That would be a very useful review.

Just got my copy and I’m using it on the GX85. Tested and seems mine doesn’t have the issue. It’s a great and sharp lens!

great video, thanks for information complete. my next lens it's this for G7

Subbed. Thanks for the review.

Thanks for this. I wondered why I got some soft results. Tried what you suggested and it sharpens up a treat. Very pleased with the results and it is not particularly difficult, just a matter of switching from for example Aperture priority to manual. What a difference. Shall have to experiement on my other lenses now!

I have these lens thank you for this

Спасибо!)) Хороший обзор, плюс получил удовольствие от родного акцента))

Now this is a review!

Great review. This will be my first lens with GH5 cam. I was looking for low light lens and cheap one and this will fit the bill i think?

I just picked mine up today for $150 USD. You can't really beat that price 😊! Thanks for the video sir.

How are you liking the G9? I am very pleased so far with it and it is my first micro four thirds camera. Your reviews are very good.

Great review! For what it's worth (in case there are any prospective buyers out there watching this video), I'm using this lens and not noticing near the amount of the focus problems as are shown in the video here (I'm using it on a GX85 body; perhaps some bodies have a mechanism for dealing with focus shift?). The example that really stuck out to me is the transit sign around 4:30, what's shown in the video is quite an egregious example of the focus shift problem, and all in all the poorly focused images documented here almost kept me from buying the lens. I bought the lens yesterday (yay Amazon same-day) after much deliberation, primarily because of the price/performance factor. I took it out today to do a little field testing of my own, taking some simple shots of street signs and construction notices, and I'm pleased to say that I wasn't able to reproduce a scenario where I ended up with poor focus on the text (using the tests documented here at f2.8, f4.0, f5.6). I am not discrediting your experimentation/research on focus shift; I believe every bit of it and it's entirely possible that my experience is not the same as the majority of people. It's a very well done explanation and demonstration, and I really appreciate the effort you put into reviewing the lens and your video explaining focus shift, it really helped me out when evaluating this lens. But as you mention in the video, it's absolutely a great lens and I'm very happy with my purchase!

Would love to hear what you think about the 20mmf1.7 lens and the 15mmf1.7 Always enjoy your reviews.

Damn what a difference!

After hearing I'm an idiot for not having this, I bought it right away. Phew

very good review. Thank you for that.

Thanks so much for the great review! I use a G85, primarily for video and usually indoors, so I often shoot around f1.7-2.8. It seems like the focus shift on this lens really shouldn't affect me at all, but I'm curious if the shift at f4 would be noticeable at all in videos that have been recorded at 4k, downsampled to 1080p. I could be thinking about this completely wrong, it's still very early in the morning for me hahahahaha! Edit: I'll have to give this a try as soon as the 25mm 1.7 makes it to my door, just waiting on delivery.

I had my eye on this camera for some time now. And now this video made me steer away from it. AF issue and focus breathing. *sigh. I really wanted the 4k60 on this. I guess I'll just go with a Canon. Thank you for this video! Very helpful!

great bang per buck lens ,as long your aware and take into account the focus shift at the problematic apertures.

Thanks for this review. How do you focus with closed aperture? I'm still new in photography.

No mention of the Olympus 25/1.8? Few would be deciding between the Panny 25/1.7 and the Oly 25/1.2 Pro, but plenty would be deciding between the 1.7 and the Oly 1.8. Especially important would be sharpness differences, flare differences, and the focus shift issues compared.

Hi , I don't know is better to buy Pana Leica 25mm f/1.4 Summilux for my GX80 or buy used fuji x100 ? thx

I'm very curious to know if the Yongnuo YN25 f/1.7 also suffers from the same focus shift issue. That's even cheaper than the Panasonic and looks like a great deal.

Do you know how to fix the focus shifting problem on an Olympus body?

I have this lens and never new about the focus shift problem until I found your review. I also have a lot of other Panasonic lenses like the 12-35mm f/2.8, 42.5mm f/1.7, 14-140mm f3.8-5.6, 100-300mm f/4.0-5.6 and the Sigma 30mm f/2.8 lenses. Do you know if these lenses also have focus shift problems? Thanks for bringing this problem to light.

Sirve para Gh5s?

Thank you for great explanation of focus shift! I was really disappointed with corner sharpness of my copy as I didn't know about this issue. However, suggested workaround of Constant Preview in M mode does not help with my G85. Corners are almost out of focus till f5.6 and the center sharpness improves rather than degrades with higher f numbers (as opposite to your experience) being the sharpest at f4 to f8 (center sharpness is really awful below f2.8 in comaprison with f4). This lens drives me crazy! :D I know I get what I pay for and the lens is superb at f5.6/f8 IMO. Although, your copy seems to be already perfect from the lowest apertures. Those apertures are the main reason I bought it. Do I just have a bad/decentered copy? Thank you! I love your reviews!

Question....When you take the steps to correct the issue from watching the other video, how far do you close the aperture to correct focus shift? Do you close it down as far as it will go or what?

I have two questions: 1. Do you hear focusing noise during filming? 2. Is the focus breath issue away after the G9 firmware update of May 2018?

hello. do you have any similar recommendation to help with focus shift solution for olympus EM1 mk2, which you demonstrate with the panasonic?

Can I just avoid using F2.8 to F4 to make the image sharper?

I ended up upgrading this lens for the 25mm f1.4 even if at first I wasn't considering doing it. Light wise it's not a big difference but color and contrast is better with the f1.4 and side by side shoot would reveal some nice improvement specially for someone that shoot wide open most of the time. I had some focusing inconsistency with the f1.7 and now I can see what was the real problem, focus shift.

sad,and it looks a very nice lens,but think I'll go with the 20mm lens for my G7 🤔

Do you know if this issue applies to the Leica 25mm f/1.4 lens?

I am not an idiot,I am going to get one to prove it. You would make a good salesman,

Did you update the firmware? Notice any difference?

I just tested my 5 Lumix lenses with my GX8 and it seems the only lens affected by focus shift among them is the 25/1.7. It's clearly visible! I had the camera on a tripod, first shot auto-focused at f/4 in A priority (hence lens aperture automatically fully opened) and second shot in M mode (constant preview on) at same f/4 (hence lens focused with aperture set at effective f/4). The other four lenses are: 14/2.5, 15/1.7, 42.5/1.7, 12-35/2.8, the latter tested at both ends of zoom range. I wonder if Panasonic could solve this absurd issue via firmware update...

what is the exact purpose of the 1.7 lense, for what exactly would you use it ? small distance shoots ? lowlight shoots ?

I tried my 25mm f1.7 at several apertures and on several different subjects, with constant preview on and off (in manual focus). I found no difference in sharpness.

Can focus shift problem be avoided if using Olympus camera? Pana 25mm is cheaper than Oly 25mm. Would like to consider this. But I already have manual 25mm lens. Maybe it would only be good for video.

I don't know why you would recommend a lens that you have to work around to use. Not sure if this was just a bad copy of your lens, but if this is what is to be expected, I will look elsewhere for a 25mm prime for my kit. Otherwise, I do enjoy your channel, keep up the good work!

Hmm. At f2.8 it has focus shifted from center focus to front focus. You said that it got better at f5.6 but it didnt. As you can see clearly that stopping up the aperture number it only made the word FOCUS sharper but the lens is actually even MORE front focus and still less in back focus. Meaning this particular lens you have has front fcous issues. When stopping up the aperture is should be even focus front and back and not just one way. Thats why the more you close the aperture the more sharper close and far objects are, but ofcoarse you already knew that. This lens along with the 42.5mm panasonic is one of the best panasonic primes out there. If it werent for the tiny dust and fiber lins that found itself into the lens element on my 25mm i might not try to sell it.

Do you think anything has changed firmware 1.1? I'm curious because Panasonic modified some of its focusing functions.

At first I regretted watching this video, I totally lost confidence in my lens and have spent a few weeks looking for a replacement and almost bought the Olympus f1.8. Then I came to my senses, this guy isn't a scientist and I am, check the damn lens out Vici. So I thought I am not aware of any problems using this lens, in fact I have loved it. So I looked through my last two years folders and pulled out the photos in question. One of the first taken when I got it was a photo in an atmospherically lit coffee bar taken at f1.7; almost the whole room is acceptably sharp. Its a 25mm lens of course its sharp, the depth of field is almost infinite, how can focusing effect that? I looked through , many at f4 or thereabouts and they were fine. So what have you done? I looked again. You have focus tested on a sheet of A4 which means extreme macro, the position where light waves are defracted the most and aberrations are maximum; at that distance the DoF is razor thin. All things and especially lenses have errors and aberrations and have a degree of accuracy associated with them so you have measured the extreme limit of accuracy of this lens. So will I ever see this effect, yes if i try focussing this close stopped down; so for that I thank you, something to bear in mind. Will I ever see it in practice? Well in two years I haven't so today I took it out and tested it to destruction on architecture and gardens. The results were spectacular with even a crisp photo taken at f2.8 with a x2 crop of a brilliantly coloured scarlet tiger moth. No sign of unsharpness. So now I am glad I watched this video because I am now sure that this is one of the best lenses I own (no feint praise as my serious kit is Leica); its spectacularly good and a bargain at this price. So guys don't be put off by this video, its a good example of a little knowledge being a dangerous thing; just dont expect to focus at less than a foot at f4. You get this problem with Leica lenses and fanboys are always complaining that Leica tailors the performance so you cant get these sub standard settings, so with this lens you are getting something extra for nothing ; dont complain about it just be thankful Panasonic isn't so perfectionist and lets you set these as they may be a life saver one day. If it bothers you then do what Leica does and dont focus less than 3ft ;-)

How can I shoot in closed aperture

I'd ordered one of these when I saw your video. I immediately performed extensive testing on mine when it arrived. It does not show ANY focus shift. I tested it up close at mid distance and distant. Perfect at every aperture. Now, maybe it's because I'm using OMD-EM1 mark 2. Have you tried another sample of the lens?

First