Four at 5X: A pixel peep show!

dmillard · Post by **dmillard** » Sun Jan 23, 2011 2:51 pm

I just tested four objective/lens combinations at 5X (4.72mm horizontal image field on my 23.6mm sensor): Nikon 4/0.20 Plan Apo (WD=15mm), Nikon 4/0.13 Plan Achromat (WD=16.22mm), and a Mitutoyo 5X/0.14 M Plan Apo (WD=34mm), with a 180mm Fujinon A and 172mm Surplus Shed achromat as tube lenses (thanks for the tip John

).

The Mitutoyo objective shoulder was approximately 55mm from the physical centers of each tube lens.

I used a Vivitar 283 flash through three fiber optic light guides, with the light slightly diffused through a cylinder of Lee 251 1/4 White Diffusion gel. Images were taken at 25μm increments for the Nikon 4/0.13 and Mitutoyo objectives, and at 12μm increments for the Nikon Plan Apo. They were then stacked in ZS PMax, and processed minimally but equally in Photoshop (slight Levels adjustment and USM sharpening).

Wing of unidentified lycaenid, Mitutoyo M Plan Apo with 180m Fujinon A

Center crops (800x300 pixels):

Mitutoyo + Fujinon

Mitutoyo + Surplus Shed

Nikon Plan Apo

Nikon Plan Achromat

Corner crops:

Mitutoyo + Fujinon

Mitutoyo + Surplus Shed

Nikon Plan Apo

Nikon Plan Achromat

Although all of the lenses performed very closely, I'm especially impressed with the image resulting from the combination of the Mitutoyo plus Fujinon A. It's sharp and contrasty across the entire frame. The Nikon Plan Apo image has the best center quality, but deteriorates slightly in the corners. The one from the Mitutoyo/Surplus Shed achromat is a little softer - I'll retest this combination after making a baffle in the adapter to cut any potential flare. It's also worth pointing out that this tube lens is a sample size of one; at $9, I may also test one of its siblings!

David

Charles Krebs · Post by **Charles Krebs** » Sun Jan 23, 2011 2:56 pm

David,

Thanks again for another meticulously done comparison!

dmillard · Post by **dmillard** » Sun Jan 23, 2011 3:23 pm

Thanks Charles!

David

Craig Gerard · Post by **Craig Gerard** » Sun Jan 23, 2011 3:25 pm

David,

Thanks again. It provides good insight for readers.

Is the 'Fujinon A' the Fujinon A 180mm f/9 ?

Craig

dmillard · Post by **dmillard** » Sun Jan 23, 2011 3:33 pm

Craig Gerard wrote:David,

Thanks again. It provides good insight for readers.

Is the 'Fujinon A' the Fujinon A 180mm f/9 ?

Craig

Thanks Craig -

It also provides good insights for me

. The lens is a Fujinon A 180mm f/9 - I really liked using this lens with a medium format view camera, but don't seem to use that system much any more

. I'm happy it does such an outstanding job in its new role (and I didn't even take it off its lensboard!).

David

RogelioMoreno · Post by **RogelioMoreno** » Sun Jan 23, 2011 4:26 pm

David,

Very good comparison, thank you for sharing.

Rogelio

Craig Gerard · Post by **Craig Gerard** » Sun Jan 23, 2011 6:51 pm

David,

For these comparisons was the Fujinon 180/9 focussed at infinity from the sensor?

Craig

rjlittlefield · Post by **rjlittlefield** » Sun Jan 23, 2011 7:14 pm

David, another excellent comparison!

Since this is 5X on a 1.6 crop sensor, I'm interested to know how these combinations would compare against the Nikon CFI60 10X NA 0.25 Plan Achromat pushed down to ~5X on a ~100 mm tube lens. I was surprised at how well the corners held up when I tried that (HERE).

Is this a comparison you're able to do?

--Rik

dmillard · Post by **dmillard** » Sun Jan 23, 2011 7:15 pm

Craig Gerard wrote:David,

For these comparisons was the Fujinon 180/9 focussed at infinity from the sensor?

Craig

No. The Fujinon 180/9 only provides a magnification of 4.5X with the Mitutoyo objective when it is extended to infinity. Both it and the 172mm Surplus Shed lens (maybe I should just call it the Morfanon

) were extended beyond infinity to reach 5X. I'm making a more rigid setup so that I can test it at even greater extensions, to contrast the image quality obtained with that derived from longer focal length tube lenses or teleconverters. Hopefully next weekend!

David

dmillard · Post by **dmillard** » Sun Jan 23, 2011 7:20 pm

rjlittlefield wrote:David, another excellent comparison!

Since this is 5X on a 1.6 crop sensor, I'm interested to know how these combinations would compare against the Nikon CFI60 10X NA 0.25 Plan Achromat pushed down to ~5X on a ~100 mm tube lens. I was surprised at how well the corners held up when I tried that (HERE).

Is this a comparison you're able to do?

--Rik

Thanks Rik,

Our messages must have just crossed! Testing the CFI60 10X against the Mitutoyo was actually already on my curiosity list.

I may test it with a 105mm enlarger lens and see how that works, unless someone else tests it first.

David

Craig Gerard · Post by **Craig Gerard** » Sun Jan 23, 2011 8:18 pm

David wrote:I may test it with a 105mm enlarger lens and see how that works, unless someone else tests it first

I'm set up to do this now (CFI60 10X > EL-Nikkor 5.6/105mm > bellows > Canon 50D).....what extension from sensor to objective shoulder would you recommend/suggest? (@160 FOV = 3.9mm)

*later note. Image obtained using the above configeration = Very good!

Craig

dmillard · Post by **dmillard** » Mon Jan 24, 2011 2:16 am

Craig Gerard wrote:
David wrote:I may test it with a 105mm enlarger lens and see how that works, unless someone else tests it first
I'm set up to do this now (CFI60 10X > EL-Nikkor 5.6/105mm > bellows > Canon 50D).....what extension from sensor to objective shoulder would you recommend/suggest? (@160 FOV = 3.9mm)

*later note. Image obtained using the above configeration = Very good!

Craig

Good morning Craig,

Looking forward to seeing your results!

David

Craig Gerard · Post by **Craig Gerard** » Mon Jan 24, 2011 4:10 am

David wrote:Looking forward to seeing your results!

It's just a boring shot of a micrometre slide (for now). I use this method as the first stage when examining lense combinations. It is quite unforgiving of any setup alignment issues (this is a good thing). When my 5X Mitutoyo arrives I will then be able to compare results (also still waiting to receive a 'flat' M26 adapter). In the meantime, I'll see what happens when a 80mm or 63mm EL-Nikkor is used as the tubelense

Craig

morfa · Post by **morfa** » Mon Jan 24, 2011 4:10 am

Very, very interesting David! Thank you so much for doing these top quality comparisons!

Blame · Post by **Blame** » Mon Jan 24, 2011 5:13 am

Hi David.

I have only just ordered a surplus shed lens... and now you show it being beaten. Sigh.

The fujinon clearly has better contrast. Do you think that is the sole cause of the improvement, or is it sharper too?

This does make me wonder about the mitutoyos. Perhaps they are letting a lot more off axis light than others. The front lens certainly looks rather exposed.

There is one good thing about them... that huge working distance. I wonder if selotaping on a short black paper hood is worth trying. Just to keep out stray light from the flash.

You mention making a baffle. I suppose I should wait till it is made, but I am curious as to what the plan is. I suppose to the initiated that one word explains it all, but alas I am baffled.