Brian Lavoie
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Is the pan 25 a lot better than new sigma 30 for image quality?
- Thread starter Brian Lavoie
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bluelemmy
Senior Member
The shop that lent me the lens has them on sale for £86 now!
Alumna Gorp
Senior Member
Which is why the LX3 was such a failure: no one ever zoomed the lens beyond 50mm equiv :-D
zenit_b
Well-known member
I don't have the sigma ... it looks a good value lens .... I DID buy the Panasonic 25mm lens though.
I know the question was about "image quality" but I am going to interpret the image quality of a photo as being more than just the maximum sharpness it shows somewhere in the frame....
.. for what it is worth here are MY reasons for buying the lens
- Reason 1 - for reasonably close subjects you can get some nice looking background blur if shooting wide open
- Reason 2 - f/1.4 is called "fast" for a reason - the clue is in the name!! - I like to do fleeting snapshots outdoors - capturing the moment as it happens - and even if the subject is moving the f/1.4 aperture pushes the shutter speed up really high. its a nice lens for this - particularly if its on an EVF equipped camera (like my G2) where you can focus on a specific point pretty instantly.... Frozen subject, blurred background ...thats the RIGHT way round for me and more what I personally am thinking of when I think of a quality image
- Reason 3... err.... price !!! I got mine in the Panasonic cashback mania in the UK last year - so it was £379 after £50 cashback... alright ... I agree it was still expensive ...but given I am in u43 for the long haul, and given I knew the lens would probably never be cheaper, I bought it.
Your mileage may vary on this and if you are shooting static, distant subjects it probably isn't worth paying the extra over the Sigma. Also with no current Panasonic cashbacks on the 25mm lens there is no real driver to buy it immediately... take longer to decide or just go with the Sigma for now....
I know the question was about "image quality" but I am going to interpret the image quality of a photo as being more than just the maximum sharpness it shows somewhere in the frame....
.. for what it is worth here are MY reasons for buying the lens
- Reason 1 - for reasonably close subjects you can get some nice looking background blur if shooting wide open
- Reason 2 - f/1.4 is called "fast" for a reason - the clue is in the name!! - I like to do fleeting snapshots outdoors - capturing the moment as it happens - and even if the subject is moving the f/1.4 aperture pushes the shutter speed up really high. its a nice lens for this - particularly if its on an EVF equipped camera (like my G2) where you can focus on a specific point pretty instantly.... Frozen subject, blurred background ...thats the RIGHT way round for me and more what I personally am thinking of when I think of a quality image
- Reason 3... err.... price !!! I got mine in the Panasonic cashback mania in the UK last year - so it was £379 after £50 cashback... alright ... I agree it was still expensive ...but given I am in u43 for the long haul, and given I knew the lens would probably never be cheaper, I bought it.
Your mileage may vary on this and if you are shooting static, distant subjects it probably isn't worth paying the extra over the Sigma. Also with no current Panasonic cashbacks on the 25mm lens there is no real driver to buy it immediately... take longer to decide or just go with the Sigma for now....
JosephScha
Veteran Member
I'm sure that's true but I bought the 25mm f/1.4 anyway, and I'm very glad I did.
Aleo Veuliah
Forum Pro
I love cats like you already know. Lovely pictures of them. Liked much. Wonderful creatures.
- About the Panasonic Leica I think one thing it has better, like all PL lenses, is the depth of color. Like you said sharpness is not all.
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bluelemmy
Senior Member
mfj197
Leading Member
The PL25 is a very different lens to the Sigma 30. At all comparable apertures it is a bit sharper, on the cusp of being noticable. The results, according to the oft-repeated LensRentals tests, are as follows (first number is centre sharpness measured by MTF50, second is average across the frame:
. PL25 Sigma 30mm
F1.4 690 590 -
F2.8 960 820 825 690
F4 980 850 910 740
The huge difference though is that the PL25 will go to F1.4 whereas the Sigma's fastest aperture is F2.8. Thus the PL25 is letting four times as much light hit the sensor, allowing use of a much lower ISO or much faster shutter speed. F1.4 on the 25 also gives a much shallower depth of field, which is the reason a lot of people like this lens. Compare the following for a typical portrait:
. PL25 Sigma 30mm
Subject distance
(for same framing) 5 feet 6 feet
Depth of field 0.51 feet 1.02 feet
Not only is the depth of what is in focus much shallower, but the background is much more blurred. Only you can decide whether this difference is worth the considerable extra expense.
Some examples of PL25 at maximum aperture:
Michael
. PL25 Sigma 30mm
F1.4 690 590 -
F2.8 960 820 825 690
F4 980 850 910 740
The huge difference though is that the PL25 will go to F1.4 whereas the Sigma's fastest aperture is F2.8. Thus the PL25 is letting four times as much light hit the sensor, allowing use of a much lower ISO or much faster shutter speed. F1.4 on the 25 also gives a much shallower depth of field, which is the reason a lot of people like this lens. Compare the following for a typical portrait:
. PL25 Sigma 30mm
Subject distance
(for same framing) 5 feet 6 feet
Depth of field 0.51 feet 1.02 feet
Not only is the depth of what is in focus much shallower, but the background is much more blurred. Only you can decide whether this difference is worth the considerable extra expense.
Some examples of PL25 at maximum aperture:
Michael
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All these photos you've posted do not to support your statement. They could be taken with ANY lens - 1.7/20, 2.8/30, 1.8/45 and even my zoom 14-45.mfj197 wrote:
The PL25 is a very different lens to the Sigma 30. At all comparable apertures it is a bit sharper, on the cusp of being noticable. The results, according to the oft-repeated LensRentals tests, are as follows (first number is centre sharpness measured by MTF50, second is average across the frame:
. PL25 Sigma 30mm
F1.4 690 590 -
F2.8 960 820 825 690
F4 980 850 910 740
The huge difference though is that the PL25 will go to F1.4 whereas the Sigma's fastest aperture is F2.8. Thus the PL25 is letting four times as much light hit the sensor, allowing use of a much lower ISO or much faster shutter speed. F1.4 on the 25 also gives a much shallower depth of field, which is the reason a lot of people like this lens. Compare the following for a typical portrait:
. PL25 Sigma 30mm
Subject distance
(for same framing) 5 feet 6 feet
Depth of field 0.51 feet 1.02 feet
Not only is the depth of what is in focus much shallower, but the background is much more blurred. Only you can decide whether this difference is worth the considerable extra expense.
Some examples of PL25 at maximum aperture:
Michael
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mfj197
Leading Member
texinwien
Senior Member
Your statement is flat-out wrong.s_grins wrote:
All these photos you've posted do not to support your statement. They could be taken with ANY lens - 1.7/20, 2.8/30, 1.8/45 and even my zoom 14-45.mfj197 wrote:
Michael
Do you know that what you're saying is wrong, and say it anyway to make yourself feel better? Or do you sincerely not understand that it's wrong, and why? If the latter, you'd be well advised to refrain from making such ill-informed statements about subjects you don't understand in the future.
I'll just take this last photo, for example, and we'll consider the Sigma 30mm, f/2.8. Since you said all of the pictures "could be taken with ANY lens", I can pick any lens and any of Michael's pictures.
This particular photo was taken at f/1.4, ISO 200, S=1/160. If Michael had used the Sigma, he would have been at f/2.8, two stops slower. he would have had to either quadruple his ISO or quarter his shutter speed.
Had he quadrupled his ISO, the image would have significantly more noise. Had he quartered his shutter speed, the image would, almost certainly, be less sharp, due to the effect of subject motion.
And that's not even mentioning the 2-stop difference in DOF/bokeh.
So no, these photos could not have been "taken with ANY lens", as you claim. Your statement is flat-out wrong.
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texinwien
Senior Member
Here's the deal, the 25mm f/1.4 can do all of the things both FFS and sbszine listed. It can do detailed subjects by daylight or flash. It can do handycam style deep DOF video.
Now if those things are all you'll ever need to do, you'll probably be fine with the Sigma.
But if you need (or just want) a lens that can do all of those things AND also handle available light photography, shallow DOF (stills and video) and freezing motion, and you don't mind the higher price, get the 25mm f/1.4.
In short, the 25mm f/1.4 can do everything the Sigma can do (and can do it better than the Sigma, to boot), plus it can do a number of things that the Sigma can't do.
It's up to each photographer to decide whether the extra things the 25mm f/1.4 can do is worth the price premium.
I mean, this approaches a tautology, people. There's really nothing to argue about, assuming Cicala's numbers are accurate...
tex
He could have taken that with any lens, just the results might be different ;-) Anyway with the OMD the IBIS would soak up some of the slower shutter and iso400 is no biggie either, even iso800 would be totally fine with this subject, 1/160 is a good speed if she's not too active, but below 1/60 would probably be OK if you took a 3 shot burst. DOF calculator says 1m subject ie 3ft only( this could be such) will only yield a few cm difference so if the background is far enough away then this is actually very doable with the 30mm f2.8, I think the 20mm f1.7 is pushing it due to FL, I never get much blur with that one for such a subject. The zoom though I would say would be impossible with! far too slow for the object distance.texinwien wrote:
Your statement is flat-out wrong.s_grins wrote:
All these photos you've posted do not to support your statement. They could be taken with ANY lens - 1.7/20, 2.8/30, 1.8/45 and even my zoom 14-45.mfj197 wrote:
Michael
Do you know that what you're saying is wrong, and say it anyway to make yourself feel better? Or do you sincerely not understand that it's wrong, and why? If the latter, you'd be well advised to refrain from making such ill-informed statements about subjects you don't understand in the future.
I'll just take this last photo, for example, and we'll consider the Sigma 30mm, f/2.8. Since you said all of the pictures "could be taken with ANY lens", I can pick any lens and any of Michael's pictures.
This particular photo was taken at f/1.4, ISO 200, S=1/160. If Michael had used the Sigma, he would have been at f/2.8, two stops slower. he would have had to either quadruple his ISO or quarter his shutter speed.
Had he quadrupled his ISO, the image would have significantly more noise. Had he quartered his shutter speed, the image would, almost certainly, be less sharp, due to the effect of subject motion.
And that's not even mentioning the 2-stop difference in DOF/bokeh.
So no, these photos could not have been "taken with ANY lens", as you claim. Your statement is flat-out wrong.
texinwien
Senior Member
Well, that's the point. He couldn't have taken that picture, because the results would have been different. Nothing to argue about here.A2T2 wrote:
He could have taken that with any lens, just the results might be different ;-)texinwien wrote:
Your statement is flat-out wrong.s_grins wrote:
All these photos you've posted do not to support your statement. They could be taken with ANY lens - 1.7/20, 2.8/30, 1.8/45 and even my zoom 14-45.mfj197 wrote:
Michael
Do you know that what you're saying is wrong, and say it anyway to make yourself feel better? Or do you sincerely not understand that it's wrong, and why? If the latter, you'd be well advised to refrain from making such ill-informed statements about subjects you don't understand in the future.
I'll just take this last photo, for example, and we'll consider the Sigma 30mm, f/2.8. Since you said all of the pictures "could be taken with ANY lens", I can pick any lens and any of Michael's pictures.
This particular photo was taken at f/1.4, ISO 200, S=1/160. If Michael had used the Sigma, he would have been at f/2.8, two stops slower. he would have had to either quadruple his ISO or quarter his shutter speed.
Had he quadrupled his ISO, the image would have significantly more noise. Had he quartered his shutter speed, the image would, almost certainly, be less sharp, due to the effect of subject motion.
And that's not even mentioning the 2-stop difference in DOF/bokeh.
So no, these photos could not have been "taken with ANY lens", as you claim. Your statement is flat-out wrong.
It might be fine, but it would have more noise than that picture, which was shot at ISO 200.
Again, if only one of the shots in the 3-shot burst was OK, it might not be exactly this one, with exactly this look, and there's no guarantee that any of the individual photos from the burst would have frozen the movement exactly as well as using 1/160 did.
I mean, you can talk around it all you want, and it's great that the E-M5 has IBIS and excellent high ISO capabilities. Those are some of the things I love about my E-M5.
But those things are neither here nor there in this discussion. The Sigma 30mm f/2.8 could not have taken that picture. It simply couldn't have.
The few cm difference, again, makes the resulting image different than that image with which we're comparing. It may not be a huge difference, but it's a difference nonetheless.
As you've admitted in each of these points, it would have been impossible to replicate that image under those exact conditions with the Sigma 30mm f/2.8. A similar image, perhaps, but not the exact image, and it's up to each photographer to decide whether the difference is worth the price premium.
Again, there is nothing to argue here. These are the facts.
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BTW the 30mm is perfectly able of doing bokeh at moderate speeds as shown in Lenstip samples. See here:
Loading…
www.dpreview.com
I knew that in the end the argument would be about bokeh, but since I couldn't care less I had a good laugh
Lenstip is always helpful even when grumpy
Am.
amalric wrote:
BTW the 30mm is perfectly able of doing bokeh at moderate speeds as shown in Lenstip samples. See here:
http://www.dpreview.com/forums/post/51593273
I knew that in the end the argument would be about bokeh, but since I couldn't care less I had a good laugh
Lenstip is always helpful even when grumpy
Loading…
www.lenstip.com
As you see there are two fine portraits with good bokeh, both shot at 200 ISO and 1/320 sec.
So again no great limitations in using the Sigma 30mm.
Am.
Photostream: http://www.flickr.com/photos/amalric
texinwien
Senior Member
I don't need to. Here's what you said:
All these photos you've posted do not to support your statement. They could be taken with ANY lens - 1.7/20, 2.8/30, 1.8/45 and even my zoom 14-45.
Since you said "all these photos ... could be taken with any lens", I can select any photo and any lens to prove you wrong, which is exactly what I did.
Perhaps you weren't selective enough?
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So what you're saying is that you could leave the camera and subject in the same spot and the 25mm @ f/1.4 and 30mm f/2.8 will give you the same shot?
Nope!
For kicks, let's also throw in the 20mm f/1.7 as you say you don't get enough blur with that, in order to see if you would be happy with the 30mm's performance.
What you're neglecting to account for is the magnification provided by the lenses, which is M=f/(f-d). For the image to be framed the same, the magnifications mush be equal. So assuming a 1m subject distance for the 25mm we solve 25/(25-1000) = 30/(30-x) and find that to get the same framing we need the subject to be 1.2m away with the 30mm.
Plug that into your DoF calculator and you get:
20mm, f/1.7, 0.8m => 0.08m
25mm, f/1.4, 1.0m => 0.07m
30mm, f/2.8, 1.2m => 0.13m
Would you like to hazard a guess what the DoF for 25mm is if we stop it down?
25mm, f/2.8, 1.0m => 0.13m
Yes, at close focus, the DoF is closely approximated by magnification (i.e. framing) and is independent of focal length. (This is also, BTW, where the near and far limits are approximately the same so a simple "DoF" figure is meaningful.) For focal lengths this close, it can stretch really quite far.
If we push the subject out to 5m for the 25m:
20mm, f/1.7, 4.0m => 2.14m
25mm, f/1.4, 5.0m => 1.74m
25mm, f/2.8, 5.0m => 3.81m
30mm, f/2.8, 6.0m => 3.67m
Now, this doesn't account for amount of background blur (arguably more important than DoF, actually!), which depends on the actual aperture size (i.e. focal length / f number) and magnification exactly. So for equivalently framed shots we see that background blur is proportional to:
20mm @ f/1.7 : 11.8
25mm @ f/1.4 : 17.8
30mm @ f/2.8 : 10.7
So you can see that the 24mm wide open will provide a significantly more blur, while the 30mm will perform slightly worse than the 20mm. As a final thought on this, mind that these figures apply to the absolute blur so they describe how large a point at infinity will blur to. Relative blur, which is how blurred together together two points at infinity are, depends on magnification and f number and not focal length at all. So either way, background blur is handily won by the 25mm and even the 20mm beats the 30mm, even if only by a small margin.
So no, those two stops really do matter a lot when you actually look at it correctly. They matter really about two stops worth
.
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