Lens Quality

[Braineack]

I found my old N60 with a Quantaray 28-80mm f/3.5-5.6 attached.

I was curious how it would work on my D600 so I gave it a try.

Here's a comparison against my Tamron 24-70mm 2.8 VC both at 50mm, 1/125, f/5.6, iso 500.


The Tamron:

Cats 038-1 by The Braineack, on Flickr

The Quantaray:

Cats 040-2 by The Braineack, on Flickr

Hard to see it here.

But look at it 2:1:


pookie_eye_test_tamron by The Braineack, on Flickr


pookie_eye_test_quant by The Braineack, on Flickr



Just shooting things around the house provided really abysmal results. Nothing ever looks "in focus" everything is soft, even the colors are soft, there's awful chromatic aberration, and if there's any direct light in the shot it flares and clouds up the blacks.

But, had I never zoomed in, it's hard to tell

 

[manaheim]

Interesting.

As a side note... my god what a beautiful cat. What kind is it?

 

[Braineack]

and just because:


The Yawn. by The Braineack, on Flickr


He's mostly Persian but without such a flattened snout. He was a rescue from a kill shelter, so it was hard to say if he was pure bred or not, but he looks exactly like his Mother and all his siblings.

 

[Braineack]

Here's what I was talking about when I said it clouded up in light:

Tamron:

Cats 050-2 by The Braineack, on Flickr

Quantaray:

Cats 049-1 by The Braineack, on Flickr

Most of the images I took with it had that glazed look to it.

This is the lens in question: Quantaray 28 80mm Zoom Lens for Nikon D1 D2 D3 D50 D70 D80 D90 D100 D200 D300 | eBay

It's just really interesting to see the difference in a $1.2K lens of 2012 vs. the lens Ritz Camera used to sell with the N60 back in circa 1999. I'm not sure the softness has anything to do with the lens-to-sensor distance, I thought on FX bodies it was the same as film. And I know this wasn't scientific at all, just sharing my findings. I don't always buy into the whole you need the buy new lenses cause your current ones are crap, but I'd never find myself shooting on this Quantaray either, so much for trying to save $1000

 

[Overread20]

I was surprised to see the softness as the first two shots the Quantaray looks to have a touch more contrast so I was expecting it to be fairly sharp. There are a few sources for the softness;


1) Resolution - higher MP sensors require higher grade glass to perform well; especially when comparing 100% crops.

2) Lens Fungus - have you checked inside - you might have fungus which could also be causing the clouding effect. Similarly you might have a film on your lens rear or front optics (clean them) or internally they might have a dust film (fairly thick). It could also be worn off coatings.

 

[Braineack]

Having a 24MP sensor is probably more than the lens can resolve, so that's probably why it's showing up soft. But yeah, I've never quite understood the lens:sensor rendering ratio and reading about the Nyquist frequency and all the technical stuff just hurts my head.

I just cleaned the front glass element with microfiber cloth. The lens itself had never been removed from the body since day one and the rear element still looked good so I left it alone. I couldn't see fungus if there was and the coating still looked good to me; I was actually impressed that as a teenager I kept it in such good shape

 

[sm4him]

Interesting.

As a side note... my god what a beautiful cat. What kind is it?

Yeah, I'm having trouble concentrating on your actual point, which is the lens comparison, for looking at that beautiful cat. Next time, try using something less gorgeous as your test shot...

 

[Braineack]

I was going to take a picture of a circuit board, but I like excuses to take more pictures of my cats.

 

[amolitor]

I think that the Quantary is actually pretty sharp, for some definition of the word sharp. It resolves the same things, but without as much contrast, so the MTF certainly doesn't look as good. For low contrast features, it's going to go to mud a lot faster, but for high contrast stuff like fur it's not so bad. It's also pretty flarey, which is related.

Before:



After a mild curves adjustment to push the blacks down some and the highlights up slightly, and then a mild/moderate unsharp mask:



The Quantary has difference rendering characteristics, and in some ways it's not so good, but mainly the pictures it makes just need to have handled a bit differently.

 

[Derrel]

It could be as simple as a slight focusing error on the Quantaray shot. At such close range, being "off" by 3/8 of an inch would be enough to make the individual hairs around the eye not be sharp.

As to the haze...that looks like what is often called "veiling glare", and that is an optical defect that MANY zoom lenses suffer from, especially when shot in darker environments and toward brighter light sources. My older 1999-era Tokina ATX 28-80 f/2.8 AT-X Pro (lol...what a name) suffered terribly from the same issue...I called it "Der Flaremeister".