# A test of those screw-on lens adapters



## 480sparky (Aug 10, 2015)

So, you just got your first 'real' camera with a spiffy kit lens........ and you find you really like to get out and use it.  Naturally, the first thing many newbies think of is getting a few more lenses in order to extend their imaging horizons.

And one set of lenses always seems to come up of every shoppers radar is those screw-on 'wide-angle and telephoto adapters' that clog up ebay and Amazon.  My, my... what you can do with those!  Amazing wide-angle vistas of sweeping landscapes, stunning interior architectural shots.  And you can count the hairs on the leg of a bug at half a mile with that telephoto lens!












And all for less than $40!  Why bother buying more high-priced lenses when you can get an über-wide and super-telephoto for less than the cost of dinner and a movie?


I'll be the first to admit it...  whenever I think of someone dropping their hard-earned money on these I cringe.  I make no bones about it.... I think they're garbage.  But a while back, I thought, "Ya know, my experience is based on my buying into them back in the 70s.  Maybe they're better today than I expect." 

So, it's time to put my money where my mouth is.  Yes, I ponied up and bought a pair.  And here's what I got:






Each adapter came in a 3" cube box, with a little fake leather pouch, front (push-on) and rear (screw-on) caps, as well as the obligatory instruction manual.  Hey!  Now I'm all set.  Sweeping vistas.... stunning wildlife shots.... fantastic interiors...... killer sports images.


Whoa.... let's not get ahead of ourselves.  Like any lens, I wanna do a bit of testing before I commit any real shooting.  So this morning I stopped by the state capital and took a few test shots.  But first, let's start with a 'benchmark' image... one taken with the same lens I'm going to be tossing this adapters onto; my Nikkor AF-D 50mm/1.8.  It's one of the three sharpest lenses in my stable.  And like any nifty fifty, you can't beat the image quality.







OK, now for a bit of math.  What I got was both a 0.43x and 2.2x converters.  Now, when I was in school 50x0.43 ciphers out to 21.5.  And 50x2.2, according to my pencil, is 110.  Well, I don't have a 21.5mm nor a 110mm lens to compare these to, but I _do_ have a Nikkor 20mm wide and 105mm Micro.  Close enough, wouldn't you say?



So let's compare the 50mm AF Nikkor with the 0.43x converter mounted on it to the 20mm Nikkor.












What?!?!?!?  Wait just one dog-gone minute!  Those images aren't even anywhere *close* to being the same field of view!  Did I screw up somewhere?  Is my math off?  Did I get ripped off?  Where's my 'sweeping vista'?!?!?


OK, check my math.  50x0.43.  Yep. Still 21.5.  My phone's calculator says so.  So does my old-fashioned long-hand math with paper and pen.  I should be seeing two images that are relatively close in terms of field of view.


Sigh.  But no.  I'm not.  Well, let's not dwell on this any more. Let's move on to the 2.2x converter.  Now, it's pretty hard to screw up a telephoto lens because by design, they're very simple optics.  So I should be getting something close to my 105mm Nikkor Micro lens.











Well, geez Louise!  This is just about as far apart!  50x2.2 is still 110 in this universe, isn't it?  Yea, I know they're teaching 'new math' to kids these days, but is this 'new math' _that_ far off!?!?

OK, what gives?

Well, truth be told, what gives is these lenses don't even come _close_ to their advertised magnification figures.  So what 'focal lengths' do I really have?  Well, good thing I brought along my own, custom-made side-by-side lens/camera comparitor.






With this little $15 home-made rig, I can set two cameras side-by-side and compare two cameras and/or lenses with just one tripod.  Pretty handle little gadget, huh?

If you wanna make your own, just saunter down to the local hardware store and buy a mending strap and a couple of ¼x20 knobs.  Trust me, it's worth the time.

Anyhoo, with two identical cameras mounted side-by-side, aimed at the same scene, I can easily click the LiveView on and adjust one camera with my 24-120 Nikkor to match the field of view shown on the other camera with the 50mm and adapter.

And what 'focal lengths' do I end up with?











An anemic 38mm and 66mm.  If you don't want to do the math, that works out to the wide-angle adapter being more like 0.76x and the telephoto adpater as 1.32x.

OK, so let's say we're willing to accept such measly changes in our field of view.  Now for the real test..... how _sharp_ are they?  With my comparitor device, that's easy to do.

First, the 50mm Nikkor with the 0.43.....er..... 0.76x adapter v. the Nikkor 24-120 at 38mm.  As with all lenses, the corners will be the tell.  If the corners are sharp, you've got a good lens.











Would YOU accept this?


Now let's take off  the wide-angle adapter and put on the 2.2x..... er..... 1.32x telephoto adapter and race it against the Nikkor 24-120 set to 66mm.











If you had just this last image to view, you'd have absolutely _no idea_ what you're even looking at.  I don't know about you, but this image would go straight to the trash bin.


So what's the  take-away today?  Save your dinner-and-movie money and apply it towards REAL lenses.  Yes, those lenses will cost more, and be larger and heavier than the adapters.  But the whole idea is to get decent images, isn't it?  And as far I this little test demonstrates, those screw-on adapters are quite useless.


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## Derrel (Aug 10, 2015)

Great job you did of comparing these two awful accessories! I feel so bad for people who buy those things!


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## robbins.photo (Aug 10, 2015)

Ok, so read through this whole thing and my takeaway was...

Wait, you can do math with a pencil and paper?


Lol...  Seriously though, some great info here that we can refer people too when they ask about these cheap adaptors.

Two thumbs up.

Sent from my 306SH using Tapatalk


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## 480sparky (Aug 10, 2015)

robbins.photo said:


> .......Wait, you can do math with a pencil and paper?.......



Um, like,..... yeah.  It's all we had when I was a kid.


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## robbins.photo (Aug 10, 2015)

480sparky said:


> robbins.photo said:
> 
> 
> > .......Wait, you can do math with a pencil and paper?.......
> ...



Wait, you were a kid?

Holy crud.  Why am I always the last to hear about stuff like this?

Lol


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## 480sparky (Aug 10, 2015)

robbins.photo said:


> .........Wait, you were a kid?........



Yep.  And here's proof.  Dec 24, 1968 (right after listening to Apollo 8 make their now-famous Christmas Eve radio transmission):


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## robbins.photo (Aug 10, 2015)

480sparky said:


> robbins.photo said:
> 
> 
> > .........Wait, you were a kid?........
> ...



Ok.. forgive my suspicious nature here.. but you are willing to sign an affidavit stating this is not a mini-me sort of situation right?  Lol


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## 480sparky (Aug 10, 2015)

robbins.photo said:


> Ok.. forgive my suspicious nature here.. but you are willing to sign an affidavit stating this is not a mini-me sort of situation right?  Lol



As long as you're willing to sign a notarized statement that you're not really a gorilla.


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## robbins.photo (Aug 10, 2015)

480sparky said:


> robbins.photo said:
> 
> 
> > Ok.. forgive my suspicious nature here.. but you are willing to sign an affidavit stating this is not a mini-me sort of situation right?  Lol
> ...




Hmm.. that might be difficult since I am really a gorilla.  However I might get a pass on that one since my notary is too.  I'll call and check.


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## JustJazzie (Aug 10, 2015)

I got some of those with my first camera kit! Thanks goodness I had no idea what they were. Unfortunately I DID know what the free uv filter was for......

Great job on the comparison! Thanks for taking your time and money to get this done!


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