25mm f1.7 comparison shots...disappointed

Not sure that using ISO 1600 represents the best procedure & results for testing sharpness. Try it again in good light, at base ISO. I've found mine to be quite good. As good as the 20 1.7 to my eye, maybe not quite as sharp in the extreme corners.

Also, how do yoy shoot at f/1.7 with the kit lens & the Sigma in low light?

wrxpat wrote:

I find mine to be quite sharp, I compared it to my PL25 and it held up quite favorably. Perhaps theres some QC issues going on...?

Ummmmmm..........no. The only thing he/she has tested, is the NR effectiveness of whatever software he/she is using. I wouldn't even dream of testing lens sharpness at ISO 1600, on my full frame camera -let alone m4/3

speedync wrote:

wrxpat wrote:

I find mine to be quite sharp, I compared it to my PL25 and it held up quite favorably. Perhaps theres some QC issues going on...?

I think you may be right. As I mentioned, mine may be a poor example.

Ummmmmm..........no. The only thing he/she has tested, is the NR effectiveness of whatever software he/she is using. I wouldn't even dream of testing lens sharpness at ISO 1600, on my full frame camera -let alone m4/3

Ummmmmmm.......no, they were shot JPG so the processing was in-camera and identical for each. Does 1600 ISO make a good lens bad or a poor lens better? Or different?I shot several hundred shots before deciding to do an identical test. By that time the sun was dropping so ISO went up. But, the results didn't change.

The 25/1.7 is not as sharp as either of the other lenses tested.

However, to please you, I'll duplicate this for you tomorrow at base ISO. I'll venture the difference will be even more apparent.

Warren

My 25/1.7 is equally disappointing compared to my other lenses. It is not a bad lens, just very mediocre, whereas many MFT lenses are very good indeed.

In its favour, I find the resolution drops off very little towards the edges of the frame - the IQ is much more uniform across the frame than almost all the other lenses I have (except perhaps the Sigma 60/2.8, which was designed to cover APS-C format sensors and gives very uniform quality across the MFT frame).

Big D in SP wrote:

Ummmmmmm.......no, they were shot JPG so the processing was in-camera and identical for each.

That's part of the problem. Shooting in jpeg is not really a good indication. Better off to shoot raw, then convert with the same settings in the same raw converter to be able to see the real differences.

Does 1600 ISO make a good lens bad or a poor lens better? Or different?

ISO 1600 will be inherently noisy, knocking back the sharpness of any lens. Look at all the artifacts around the black text. No way you can make judgments with that as an example. Well, I couldn't anyway. If you're going to post examples to support your view, at least post some decent examples taken in good light at low ISO. We can't see all the shots you took earlier in the day. The whole point of an f/1.7 lens is to be able to open it up, & shoot 3 or 4 stops (roughly -I don't know exact apertures at all focal lengths) lower ISO than your kit lens. Which will make a huge difference as opposed to any tiny bit of sharpness you'll see pixel peeping anyway.

I shot several hundred shots before deciding to do an identical test. By that time the sun was dropping so ISO went up. But, the results didn't change.

The 25/1.7 is not as sharp as either of the other lenses tested.

However, to please you, I'll duplicate this for you tomorrow at base ISO. I'll venture the difference will be even more apparent.

Warren

No need to please me. I got my 25 for free, (part of a bonus promotion) & the only thing I'm disappointed with, is that I paid $360 odd for the 20 f/1.7. Actually, I'm not. I'm just happy with an absolute bargain. Even at full price though, I'd still be satisfied with it. I've either got a very very poor 20, or a really really good 25. Or perhaps I have realistic expectations?

There is far more to a lens than just plain sharpness. Like I wrote earlier, how do you shoot your kit lens at f/1.7 in low light? How do they render contrast & colour? Isolate your subject? No doubt there are sharper lenses out there, but that doesn't automatically make the 25 cheap rubbish.

I'm not picking on you, just giving a bit of perspective is all.

Yeah, it's terrible. Lol. Without looking at the exif (can't be bothered removing it) you tell me which is which. Both shots taken at f/1.7 in testing conditions, hard on contrast, which shows up a "poor" lens, converted from raw with the same settings in LR.

And again. With the subject on the border of the frame, where a "bad" lens will show differences

Time to stop shooting test charts boys, & get out into the real world

speedync wrote:

Big D in SP wrote:

Ummmmmmm.......no, they were shot JPG so the processing was in-camera and identical for each.

That's part of the problem. Shooting in jpeg is not really a good indication. Better off to shoot raw, then convert with the same settings in the same raw converter to be able to see the real differences.

I disagree, whenever I am testing lens-v-lens-sharpness I use in-camera Jpegs with a very low sharpness (varies with camera) so that there can be no inadvertant/hidden messing by a chosen RAW-converter depending on the lens. One less step to reduce error.

The camera willl produce Jpegs which are processed the same (plus auto lens correction, but that is known) and the sharpness differences will be apparent.

It is not a $99 lens except in very local situations. You can see why Panasonic pulled this pricing stunt if people talk about it as such and excuse problems against this price.

Even at £150 it is very affordable so you can excuse some things but to talk about it as a $99 lens is absurd.

Loga wrote:

However, it is a $99 lens as you mentioned, so I would not expect $5000 Leica lens sharpness.

It delivers f1.7 which my other lenses do not. I think the sharpness thing rather misses the point of a fast lens avoiding high ISO's which lead to smudging and worst of all colour contrast loss. Of course if you can afford a more expensive lens it may perform better but that hardly needs discussion.

MatsP wrote:

..now I know I don't need that lens. It's definitely cheap, but a cheap lens that doesn't deliver is just disappointing. Like the Sigma 19/2.8 was to me to take another example.

Lol. You're trying to tell me you can see a difference in sharpness on your phone, with images compressed to the size of a postage stamp? Pull the other one