Setting up a Nikon lens test

[shootme]

I recently acquired a Nikon 70-200mm f/2.8G ED-IF AF-S VR Zoom. I already have a Nikon 70-300mm f/4.5-5.6G ED-IF AF-S VR Zoom and an older Nikon 70-210mm f4-5.6 AF. I'd now like to put together and post a lens test between these 3 lenses, but I'm not sure the best way to go about doing this and would appreciate if someone can give me some advice on how I should set up such a test and how to present the results that might be useful for others when trying to choose lenses etc.? Any help would be grateful. Oh, the camera used will be a Nikon D300. Shootme...

[AgingEyes]

It's pretty much agreed that 70-200 f2.8 VR has very high resolution, i.e., very sharp. However, 70-300 f4.5-5.6 VR is also known to be sharp from 70mm to 135mm. Longer than that, you have to stop down more to achieve good results. I'm no expert in comparing lenses but if I have to, I probably would shoot some pics using focal lengths of 70mm, 135mm and 200mm at f4.5, f8 and f11 (the last two are especially for 70-300) The target I use will be something with details and colors. In the old days, some tested lenses by photographing newspaper, shooting brick walls, etc. After taking the photos, I will examine the shots at 100% magnification. Not any sophisticated tests by any means. But I guess they should tell you something about the sharpness, contrast, and color rendition of both lenses.

[shootme]

AgingEyes, thanks I will give that a try, hopefully this weekend if the weather holds up. Cheers...

[shootme]

It's pretty much agreed that 70-200 f2.8 VR has very high resolution, i.e., very sharp. However, 70-300 f4.5-5.6 VR is also known to be sharp from 70mm to 135mm. Longer than that, you have to stop down more to achieve good results. I'm no expert in comparing lenses but if I have to, I probably would shoot some pics using focal lengths of 70mm, 135mm and 200mm at f4.5, f8 and f11 (the last two are especially for 70-300) The target I use will be something with details and colors. In the old days, some tested lenses by photographing newspaper, shooting brick walls, etc. After taking the photos, I will examine the shots at 100% magnification. Not any sophisticated tests by any means. But I guess they should tell you something about the sharpness, contrast, and color rendition of both lenses.

AgingEyes, I've done the test, but had a few issues so I might need to do it again. With the 70-300mm I couldn't get the fstop to go to f4.5 at 135mm nor 200mm, instead only got to f4.8 and f5.3 respectively? I set the camera at ISO 200 and AP priority, so shutter speed would adjust automatically. With the 70-300 I only got to f5.6 at 300mm also. Had the same problem with the older 70-210 AF at 210mm, only got to f5.6? I wasn't expecting that...

[deckcadet]

Well, I guess you don't know about variable aperture zooms, then. The lenses as you described them are telling you that information. the aperture listed is the maximum aperture- as wide open as it will get. When it say f/4.5-5.6, it means at the widest focal length it will have a max aperture of f/4.5, and at the longest focal length f/5.6. It usually reaches the smaller one before the longest focal length.

[shootme]

Well, I guess you don't know about variable aperture zooms, then. The lenses as you described them are telling you that information. the aperture listed is the maximum aperture- as wide open as it will get. When it say f/4.5-5.6, it means at the widest focal length it will have a max aperture of f/4.5, and at the longest focal length f/5.6. It usually reaches the smaller one before the longest focal length.

Now that makes sense, thanks a bunch. By the way I saw some photo's of your's on this site. One in particular I liked; it was a shot at a Rodeo, can you tell me what lens you used? If I'm not mistaken I saw the photo on the forum where you were introducing yourself.

[AgingEyes]

AgingEyes, I've done the test, but had a few issues so I might need to do it again. With the 70-300mm I couldn't get the fstop to go to f4.5 at 135mm nor 200mm, instead only got to f4.8 and f5.3 respectively? I set the camera at ISO 200 and AP priority, so shutter speed would adjust automatically. With the 70-300 I only got to f5.6 at 300mm also. Had the same problem with the older 70-210 AF at 210mm, only got to f5.6? I wasn't expecting that...

Just like what deckcadet said.

Even some "fixed" aperture lens will also have the aperture changed somewhat. For example, when shooting real close with 105 f2.8 VR, you won't get f2.8. You'll get f3.something.

[deckcadet]

That's only a change of effective aperture and only really happens with Macro lenses. It is only reported with them anyways, and only Nikon and Tokina macros seem to report this.

shootme, that rodeo shot was taken with the D3 and Nikon AF-S 200mm f/2.0G SuperED-IF VR.

[Wild Wassa]

Shootme, this is a short info sheet on how 'Choice', a consumer group, tests lenses for image quality.

http://www.choice.com.au/viewArticle...igital+cameras.

Don't underestimate shooting a brick wall to tell you all about lenses ... AgingEyes has also mentioned this possible test pattern. I've shot brick walls and have been horrified at how ordinary some lenses are. When I was a student I spent a lot of time staring at walls ... and cursing bricklayers for their distorted lines that only my lenses could see.

Warren.

[Photo-John]

Don't underestimate shooting a brick wall to tell you all about lenses ...

I use the brick wall test all the time. In fact, I have a lens I'm testing and I did a brick wall test with it today. I haven't looked at the images yet. But the brick wall test is very, very good. Newspaper classifieds are good, too. That's why they're part of our digital camera studio testing setup.

[deckcadet]

Brick wall shooting can be useful, but it's important to draw the mental distinction between where it is useful and where it isn't.

Lenses that don't do that great on brick walls (e.g. those with greater than average field curvature at the given working distance to the wall, those that vignette or are softer in the corners, and many more) can still be superb lenses for their intended applications. Likewise, some lenses might do great for a brick wall test but fail to deliver in real world circumstances.

[photophorous]

I always like to take at least a few test shots when I get a new lens so I know it's strengths and weaknesses. Lenses are not always sharpest at f/8 and some are affected more than others by veering away from that optimal aperture. Field curvature drives me insane with wide angles, so that's reason for selling one in my book. Brick walls are great for testing curvature. Considering that we rarely stick our main subjects in the center of the frame, it's nice to understand corner sharpness at various apertures too. That's were newsprint is helpful. Real world results trump all, but a good test can give you the information you need to improve your real world results.

Paul

[Franglais]

1 Use a HEAVY tripod or your results will be meaningless.
2 Shoot at minimum ISO (200 ISO in your case)
3 Choose a subject which is representative of your normal usage. Most of the time I point the lens out of the window at the house across the way. There is brick, grass, leaves - lots of detail for the lenses to fall over
4 Choose a moment when the light is constant
5 Shoot at the maximum apertures and most useful apertures. In your case this would be f2.8, f4, f5.6 f8 and f11 (not for all the lenses obviously)
6. Shot at longest, shortest and intermediary focal lengths
7 View the results as full image to get the general look and at 200% to see the detail. Check out the center and all 4 corners

[shootme]

Thanks for all the input. There is something in each comment which should make for a great lens test.

[Wild Wassa]

Deckcadet's comment, "...in the real world," tanscends the flat field coverage that lens quality is judged on after (discounting) the 13 known aberrations that plague lenses of course.

I certainly look forward to seeing your results.

I've been looking at new Nikons all afternoon. One of the shop assistants that I talked to was amazing. She said, "I'm not into this technical stuff, I don't even like cameras." I then knew that I was talking to the right person. She then talked about lens qualities, monitor qualities, print qualities, RAW vrs Tiff vrs JPEG, then camera lens packages and suggested changes to the packages and assesed programs like Photoshop, ACDsee and Arcsoft (of which I use all three) and I could only agree with her ... I look forward to seeing your lens tests Shutterbug.

Be brutal, do your worst.

When Deckcadet wrote "the real world," the real world is about where is the focus ring, and you reach it while still correctly balancing the camera, what is the grip like, can your fingers reach the focus ring and quickly focus at all extensions of the zoom ... when the lens is retracted or fully extended.

Nowadays manually focussing a lens is generally a very complex task, not a task that is an instinctive action with digital lenses. The focus ring is not the slightest bit amenable to executing rapid focussing ... and I've endured auto focussing for a long time.

About a lens test, again, be brutal. Personally, I'd like "a real world" test ... not a rigid tripod test.

Warren.