Photoclubalpha

I tried making some usefull samples for the new Sigma 19mm f/2.8 EX DN lens as well.

Testconditions: Sony NEX 3 (FW 0.4), tripod, JPEG Fine, ISO 200, center AF area, DRO-Off. Import and export in LR4, no PP applied, no sharpening on export.

I've made center, corner and CA samples on 100% crop. See below.

Centers




As you can see, centers are pretty soft at f/2.8.

Corners




Extreme corners get exeptable from f/5.6-f/11.

CA




CA in these extreme conditions is pretty bad, no matter what aperture.

Flare (clickable)

As with the Sigma 30mm f/2.8 EX DN, flare was difficult to produce.

Sun in frame (the white stripe just under the sun, above the trees are clouds)



Sun just outside frame



Links to full size images: f/2.8, f/4, f/5.6, f/8, f/11, f/16

Apart from the CA and sharpness wide open, it seems to be a capable lens for the money (€189).

Mark

EDIT: I've seem to have made a focussing error on the f2.8 sample.

Here's a correctly focussed one. Center and corner sharpness seems acceptable.

Center f/2.8


Corner f/2.8


Click for full size.

Has anyone evaluated the performance of this lens on the NEX 7 as compared to the 16mm with & without the ECU-1 which is known to improve the latter's performance? I recognize that there is a difference in field of coverage but they are both UWA lenses and short in length making them ideal to stick in a jacket pocket.

A nice comparison also posted on the dpr forum - http://forums.dpreview.com/forums/read. ... e=41144521.

Kenneth - I can evaluate this for you if you can be a bit more specific. Firstly the physical data:

I am not sure that I would even class the NEX-7 and the 16mm as 'ideal' for a jacket pocket. The combination will fit in most jacket pockets though. The 19 mm (with lens cap) projects 24 mm (0.95 inches) further from the mount than the 16 mm. The 16 mm + ECU-1 projects 33 mm (1.3 inches) further from the mount than the 16 mm.

NEX-7 + 16 mm = 432 g (0.95 lb)
NEX-7 + 19 mm = 510 g (1.12 lb)
NEX-7 + 16 mm + ECU-1 = 553 g (1.22 lb)

I don't think the lens cap on the ECU-1 is secure enough for carrying in a pocket.

Regarding performance you don't give any indication of what is important to you, e.g. performance at infinity, middle distance, close up etc. Is it just general photography, are you a walker/climber etc. If you can provide some more information and I will try a few relevant comparisons.

The ECU-1 is good for difficult situations where you need more width and it performs well in my opinion, but suggesting that it improves (depending on what you mean by this) the 16 mm is probably going a bit far. I can imagine comparing a 24 mm equivalent with a 28 mm equivalent (although even these are very different), but with an 18 mm equavalent seems a bit pointless.

Anthony
Thanks for the data & advice. As for my suggestion that the ECU improves IQ, I'm sure I'm over the top but let's for arguments' sake say it doesn't make it worse. Most of my use of the 16 has been on the 5. It's been stuck on a belt pouch for walking around and shooting middle distance to infinity. I just got the 7 and want to get a belt pouch for it with a UWA to grab shots on the run. (Many times when we're travelling my wife doesn't want to stop while I'm fiddling to compose a shot, so I figure with 24 mpx I can crop later.) To throw more into the mix, I understand Rokinon/Samyang are releasing an 8mm f/2.8 soon. Obviously, there is no one solution but I was hoping someone had some experience to share that might make my choice easier.
Ken

Kenneth Sky wrote:Anthony
............. so I figure with 24 mpx I can crop later.) To throw more into the mix, I understand Rokinon/Samyang are releasing an 8mm f/2.8 soon. Obviously, there is no one solution but I was hoping someone had some experience to share that might make my choice easier.
Ken

Ok, I understand and am thinking of much the same, except in my case it will probably be one of the 30mm's, with the tiny 16mm in a pocket for occasional use.

If you can cope with the size and weight the Samyang has an excellent reputation and if you use it with the Fisheye Hemi plugin or similar I have been told that you can straighten the verticals without losing much width.

I used the Sigma 19mm with the NEX-7 today and like it. It may be a little better than the 16mm, but I would expect that and don't like comparing lenses of different focal length. Only looked at raw, forgot jpeg. I also noticed the CA that Mark mentioned, but I can remove it in my raw converter (Silkypix 5). I focused on a building about 25m away, but will try infinity tomorrow.

Tony

Edit: Hunting around the web for examples of the 8mm, you might have problems with the distortion, even after cropping:
http://www.photozone.de/sony-alpha-aps- ... ex?start=2
http://pentaxslr.eu/Forums/viewtopic/t=544/