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Sigma Mini-Wide II 28mm 2.8 test
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PostPosted: Sat Feb 03, 2024 4:58 pm    Post subject: Sigma Mini-Wide II 28mm 2.8 test Reply with quote
Here is a small test of the Sigma. I know that the 24mm version is quite good so can the 28mm live up to it?

The close focus ability makes it stand out.

Test shots taken with a Sony A7.


#1

#2


#3


#4


#5


#6


PostPosted: Sat Feb 03, 2024 5:06 pm    Post subject: Reply with quote
Compared to other lenses.


#1


Test scene at f/5.6



Center


Right edge


Left edge



Less contrast on the Sigma.

Overall I like the Canon the most.


PostPosted: Sun Feb 04, 2024 10:12 am    Post subject: Reply with quote
Good thing you compared them at f5,6. This is how most wide angles are used and I would gladly choose a lens that is better than others at 5,6 even though relatively underperforming at f2,8.

You must have a good copy of the nFD. Mine is not up to the level of the Minolta and that is interesting.

I found that the Canon FD 28 2,8 breechlock trounces the nFD, but that might be related to owning an average copy of the nFD. Note that my nFD is consistent through the frame without decentering so I did not envision it was a bad copy. I found tha the Canon sometimes lacks sharpness because it is uneasy to focus. The image sometimes "jump" in the viewfinder when reversing focus and I thought this lens was subject with slide bearings degradation as some Canon zooms but it seems it is not the case.(Same thing sometimes occurs with the nFD 50 1,8 but to a lesser degree).

I recognize the hint of lateral chromatic aberration of the Minolta 5/5 but that is easily fixed in post.


PostPosted: Sun Feb 04, 2024 1:09 pm    Post subject: Reply with quote
The differences are not dramatic, but I agree the Canon looks best on these images. Are the images refocused for the right edge images? The Canon looks best here, but is the focus @ infinity?

Last edited by caspert79 on Sun Feb 04, 2024 1:38 pm; edited 1 time in total


PostPosted: Sun Feb 04, 2024 1:35 pm    Post subject: Reply with quote
The close focussing makes it interesting but I find it's bokeh boring and mushy. Also it is missing some sharpness and micro-contrast the really good 28mm's have.

Last edited by D1N0 on Sun Feb 04, 2024 3:34 pm; edited 1 time in total


PostPosted: Sun Feb 04, 2024 2:29 pm    Post subject: Reply with quote
lumens pixel wrote:
Good thing you compared them at f5,6. This is how most wide angles are used and I would gladly choose a lens that is better than others at 5,6 even though relatively underperforming at f2,8.

You must have a good copy of the nFD. Mine is not up to the level of the Minolta and that is interesting.

I found that the Canon FD 28 2,8 breechlock trounces the nFD, but that might be related to owning an average copy of the nFD. Note that my nFD is consistent through the frame without decentering so I did not envision it was a bad copy. I found tha the Canon sometimes lacks sharpness because it is uneasy to focus. The image sometimes "jump" in the viewfinder when reversing focus and I thought this lens was subject with slide bearings degradation as some Canon zooms but it seems it is not the case.(Same thing sometimes occurs with the nFD 50 1,8 but to a lesser degree).

I recognize the hint of lateral chromatic aberration of the Minolta 5/5 but that is easily fixed in post.


My copy of the nFD still has smooth focusing with no issues. I hadn't used it in years and had forgot how good it was.

It could also be the adapters that impact performance when pixelpeeping like this.
I remember when I tested my Samyang 14mm f2.8 on a high end adapter and the edges got a boost in sharpness.

Maybe if someone has higher end 28mm lenses and want to compare it to the Canon we can see how it holds up.


caspert79 wrote:
The differences are not dramatic, but I agree the Canon looks best on these images. Are the images refocused for the right edge images? The Canon looks best here, but is the focus @ infinity?


The images are just focused on the center background, hand held with a possibility of errors on my part.

I took a second set and can look at the results on those.

D1N0 wrote:
The close focussing makes it interesting but I find it's bokeh boring and mushy. Also it is missing come sharpness and micro-contrast the really good 28mm's have.


I kind of agree. My go to wide angle close focus lens is a Cosina vivitar 24mm 2.8.


PostPosted: Sun Feb 04, 2024 4:00 pm    Post subject: Reply with quote
That would be Sigma Super-Wide II for me. I think it performs better than the Mini-wide. Also Vivitar 28/2 Close Focussing by Komine, and the underrated Tamron Adaptall-2 28mm 1:2.5 02B. It doesn't focus as close as the other ones .25m but it is sharp and contrasty and has nice bokeh.


PostPosted: Sun Feb 04, 2024 4:17 pm    Post subject: Reply with quote
lumens pixel wrote:

You must have a good copy of the nFD. Mine is not up to the level of the Minolta and that is interesting.


The Minolta MD-III 2.8/28mm tested here is the later [5/5] version; there is also an MD-III [7/7] version which has better corner performance. See here on my webpage for exterior differences:

http://www.artaphot.ch/minolta-sr/objektive/147-minolta-28mm-f28

S


PostPosted: Sun Feb 04, 2024 4:54 pm    Post subject: Reply with quote
I tested, not simultaneously, the Tamron 02B and the MiniWide. The MiniWide was slightly tilted so my findings are not so relevant. The 02B was well centered but had a little fungus spot and was also returned. However my souvenir is that the 02B could get really crisp by f6,7 and I did not had the same feeling about the Sigma. I would agree that the SuperWide is an excellent lens of a completely different level than the MiniWide.

I considered that the 02B was not so interesting since stopped down it was not superior to the 27A zoom which provided as a bonus all focal lenghth up to 80mm.


PostPosted: Sun Feb 04, 2024 6:17 pm    Post subject: Reply with quote
lumens pixel wrote:


I found that the Canon FD 28 2,8 breechlock trounces the nFD, but that might be related to owning an average copy of the nFD. Note that my nFD is consistent through the frame without decentering so I did not envision it was a bad copy. I found that the Canon sometimes lacks sharpness because it is uneasy to focus. The image sometimes "jump" in the viewfinder when reversing focus and I thought this lens was subject with slide bearings degradation as some Canon zooms but it seems it is not the case.(Same thing sometimes occurs with the nFD 50 1,8 but to a lesser degree).



My samples of the Canon FD 28 mm f/2.8 SC and nFD 28 mm f/2.8 are very similar in terms of resolution and contrast but the older breechlock version has a much smoother focusing ring. Nethertheless, the helicoids of your nFD 28 mm f/2.8 and nFD 50 mm f/1.8 samples might benefit from a regreasing, my samples are perfectly smooth.


PostPosted: Sun Feb 04, 2024 6:28 pm    Post subject: Reply with quote
lumens pixel wrote:
I tested, not simultaneously, the Tamron 02B and the MiniWide. The MiniWide was slightly tilted so my findings are not so relevant. The 02B was well centered but had a little fungus spot and was also returned. However my souvenir is that the 02B could get really crisp by f6,7 and I did not had the same feeling about the Sigma. I would agree that the SuperWide is an excellent lens of a completely different level than the MiniWide.

I considered that the 02B was not so interesting since stopped down it was not superior to the 27A zoom which provided as a bonus all focal lenghth up to 80mm.


The Sigmas of that time show some sample variation. Up to now, i've tested three samples of the "original" Mini -Wide 28 mm f/2.8 and all were inferior to similar lenses from other brands (Tokina, Tamron, Vivitar, Panagor). A good sample of the Mini - Wide II might turn out as being a good or slightly better as the best independant lens manufacturer's lenses but still slightly inferior to major camera brand lenses, the multi coating of Sigma lenses being less effective. BTW, I've got a very good sample of the Super-Wide II 24 mm f/2.8 in Canon EF mount and a mediocre (decentered) sample in Nikon MF mount.


PostPosted: Mon Feb 05, 2024 3:14 pm    Post subject: Reply with quote
Test scene #2 At f/5.6


#1



#2 Right


#3 Left


#4 Center


PostPosted: Mon Feb 05, 2024 5:35 pm    Post subject: Reply with quote
Seems more even to my eyes.


PostPosted: Wed Feb 07, 2024 2:14 pm    Post subject: Reply with quote
lumens pixel wrote:

I found that the Canon FD 28 2,8 breech-lock trounces the nFD, but that might be related to owning an average copy of the nFD. Note that my nFD is consistent through the frame without decentering so I did not envision it was a bad copy. I found that the Canon sometimes lacks sharpness because it is uneasy to focus. The image sometimes "jump" in the viewfinder (...).


I have to correct this statement. I explained in this thread that there was a kind of longitudinal slack in this lens that is quite common in the nFD line to various extents: http://forum.mflenses.com/canon-fdn-2-8-28mm-t82121.html

I was therefore unhappy with my copy on the nFD 28 2,8.

I just bought another copy of this lens and it seems the problem is absent. So I could state no more that the FD is superior to the nFD, except the fact that build quality is probably better.


PostPosted: Wed Feb 07, 2024 3:40 pm    Post subject: Reply with quote
lumens pixel wrote:
lumens pixel wrote:

I found that the Canon FD 28 2,8 breech-lock trounces the nFD, but that might be related to owning an average copy of the nFD. Note that my nFD is consistent through the frame without decentering so I did not envision it was a bad copy. I found that the Canon sometimes lacks sharpness because it is uneasy to focus. The image sometimes "jump" in the viewfinder (...).


I have to correct this statement. I explained in this thread that there was a kind of longitudinal slack in this lens that is quite common in the nFD line to various extents: http://forum.mflenses.com/canon-fdn-2-8-28mm-t82121.html

I was therefore unhappy with my copy on the nFD 28 2,8.

I just bought another copy of this lens and it seems the problem is absent. So I could state no more that the FD is superior to the nFD, except the fact that build quality is probably better.


This type of longitudinal slack is typical of a helicoid-focusing lens where the original helicoid lubricant grease has failed. Very likely the helicoid is now operating "dry" with only the thickener and dry lubricant components of the original grease remaining, but with little to no base oil left.

This is why I have mentioned on various threads in this forum that a helicoid lubricant also has a stabilising function in terms of the helicoid slack. Helicoids have to be manufactured with some free slack to accommodate for manufacturing tolerances as well as differential thermal expansion of the different components. Based on the lenses I have serviced I estimate this slack to be typically up to 50 micrometers or so, depending on materials used and size of the helicoid. That doesn't sound like much but if you consider that at f/2 the single-sided depth of focus is only 60 microns or so, focus slack does become noticeable and the image and focus can indeed "jump" in the viewfinder when changing focus direction on a lens with a "dry" helicoid.

This is also the reason that applying the bare minimum of fresh helicoid grease when lubricating a lens is often not a good idea; a good grease fill between the two mating helicoid threads is required to eliminate the slack (and yes, unfortunately on some lenses that may mean oily aperture blades after a few decades, even with the best modern greases).


PostPosted: Wed Feb 07, 2024 3:43 pm    Post subject: Reply with quote
Like 1 Helpful info. Thanks.


PostPosted: Fri Feb 09, 2024 4:06 am    Post subject: Reply with quote
While I agree with the overall premise that dried out lubricants certainly -can cause- such behavior, I find in my experience and that in general it is much more often caused by loose focus ring screws introducing backlash into the focus action, and in the NFD lenses in particular, other factors are more likely to cause this. Now I have plenty to complain about regarding the design and construction of the NFD lenses, the stability of their lubricants is one area where I think they actually tend to do pretty well.
Early (pre-Series E) Nikkors, as a counter-example, certainly do have a major problem with drying lubricant, but while the NFD lubes sometimes exhibit some separation, they tend to stay much "wetter" than those of many other brands. Asahi/Pentax is the gold standard among the Japanese OEMs in this department, as their lubricants almost never separate or dry out, but Canons are really not that far behind.
With the NFD lenses in particular, I find that backlash and "jumping" focus is much more likely to be caused by a) loose screws, b) wear to plastic helical surfaces used in lower end models as a cost-cutting measure, or c) damage to nylon bushings on cam-style helicals, which are used in some of the floating element models such as the 35/2.




RokkorDoctor wrote:
lumens pixel wrote:
lumens pixel wrote:

I found that the Canon FD 28 2,8 breech-lock trounces the nFD, but that might be related to owning an average copy of the nFD. Note that my nFD is consistent through the frame without decentering so I did not envision it was a bad copy. I found that the Canon sometimes lacks sharpness because it is uneasy to focus. The image sometimes "jump" in the viewfinder (...).


I have to correct this statement. I explained in this thread that there was a kind of longitudinal slack in this lens that is quite common in the nFD line to various extents: http://forum.mflenses.com/canon-fdn-2-8-28mm-t82121.html

I was therefore unhappy with my copy on the nFD 28 2,8.

I just bought another copy of this lens and it seems the problem is absent. So I could state no more that the FD is superior to the nFD, except the fact that build quality is probably better.


This type of longitudinal slack is typical of a helicoid-focusing lens where the original helicoid lubricant grease has failed. Very likely the helicoid is now operating "dry" with only the thickener and dry lubricant components of the original grease remaining, but with little to no base oil left.

This is why I have mentioned on various threads in this forum that a helicoid lubricant also has a stabilising function in terms of the helicoid slack. Helicoids have to be manufactured with some free slack to accommodate for manufacturing tolerances as well as differential thermal expansion of the different components. Based on the lenses I have serviced I estimate this slack to be typically up to 50 micrometers or so, depending on materials used and size of the helicoid. That doesn't sound like much but if you consider that at f/2 the single-sided depth of focus is only 60 microns or so, focus slack does become noticeable and the image and focus can indeed "jump" in the viewfinder when changing focus direction on a lens with a "dry" helicoid.

This is also the reason that applying the bare minimum of fresh helicoid grease when lubricating a lens is often not a good idea; a good grease fill between the two mating helicoid threads is required to eliminate the slack (and yes, unfortunately on some lenses that may mean oily aperture blades after a few decades, even with the best modern greases).


PostPosted: Fri Feb 09, 2024 8:13 am    Post subject: Reply with quote
Brian which focus ring screws would be involved and are they easily accessible?
If the problem lies there it would result in a regression compared to old FD lenses that do not behave the same.


PostPosted: Fri Feb 09, 2024 4:34 pm    Post subject: Reply with quote
lumens pixel wrote:
Brian which focus ring screws would be involved and are they easily accessible?
If the problem lies there it would result in a regression compared to old FD lenses that do not behave the same.


That is just a genreal observation on most vintage japanese lenses, which have either washered screws attaching from the front or the set screws from the side, rather than the NFD vis a vis the original breech mounts.

They're the part that that receives the most consistent torquing/strain of any in the lens, and it only stands to reason that they'll develop play over time. Some manufacturers use glue/threadlocker to keep them in place, and others do not, which can make a difference between brands or newer and older series within a brand. IIRC, Canon does use glue on most (all?) off the NFD lenses, so I think the culprit there tends more to be their less robust overall construction, i.e., the plastic helicals and bushing wear I mentioned in my previous message.

I have a breech mount 1973 FD S.C. 50/1.8 in my hand right now, and even it has some fairly noticeable backlash in the focus action, despite next to no handling wear that would indicate exceptionally heavy use and still feeling pretty well damped. The Canon FD lenses got steadily lighter in construction over the years, and even an early FD like this is noticeably less tight than it's equivalent FL lens, which was built like a tank. I'll crack it open at some point and take a look, but if memory serves, this FD has an all-aluminum helical, whereas the FL had a bimetal one, which is subject to less wear and maintains its feel better over time.
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