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Resolve 60mm Vs UAT 85mm on a Stock Nikon DF

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#1 dabateman

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Posted 16 August 2019 - 21:27

I wanted to do an odd comparison today and Andrea's hunt for sharpest UV lens made me think of this. This is not the best UV test as I wanted to see how my best UV lenses looked on the Nikon DF as I may convert it to full spectrum. But still not sure.

The Resolve 60mm is a C-mount lens. But will mount to the Nikon using a C-mount to M42 adapter and then a M42 to Nikon F mount adapter. Testing this out, the lens will focus, and the furthest distance from subject is 8 inches from the front of the lens. However moving the lens this far away, you get a full image view without vignetting. Vignetting hits when you are 5.5 inches away from the subject on the Nikon mount with my adapters. My Baader Venus filter works without issues, but a 25mm filter in the front vignettes. I posted Pentax UAT for comparison which is 2 stops faster! and doesn't vignette when a 25mm filter is placed in the front, as the front element is smaller. However I did have a 17-31 helicoid with the UAT to get similar field of view.

Room back light Fluorescent bulbs were on for visible, and two 365nm LED bulbs were on the main subject.

Resolve 60mm @F4 ISO 800 1/4 shutter Macro visible image:
Attached Image: Resolve_800_F4_0.25_Macro_Vis.jpg

Resolve 60mm @F4 ISO 3200 Shutter 1 second with Baader venus U
Attached Image: Resolve_3200_F4_1_Macro_Baader.jpg

Resolve 60mm @F4 ISO 3200 Shutter 1 second, WB RawTherapee Baader venus U:
Attached Image: Resolve_3200_F4_1_Macro_Baader_WBRT.jpg

Resolve 60mm @F4 ISO 3200 shutter 1 second, with 25mm U330WB80 Improved filter infront:
Attached Image: Resolve_3200_F4_1_Macro_330WB80.jpg

UAT 85mm @F8 ISO 500, 1/2 shutter Visible image:
Attached Image: UAT_500_F8_0.5_Macro_Vis.jpg

UAT 85mm @F8 ISO 1600 2 second shutter with Baader venus U
Attached Image: UAT_1600_F8_2_Macro_Baader.jpg

UAT 85mm @F8 ISO 1600 2 second shutter, WB Raw Therapee Baader venus U
Attached Image: UAT_1600_F8_2_Macro_BaaderRTWB.jpg

UAT 85mm @F8 ISO 1600 2 second shutter, with 25mm U330WB80 Impoved filter in front:
Attached Image: UAT_1600_F8_2_Macro_330WB80.jpg

UAT 85mm @F8 ISO 1600 2 second shutter with Baader venus U

I used the exact same WB settings in Raw Therapee for the Resolve 60mm as with the UAT 85mm. However, the WB looks better with the Resolve. So I will need to learn how to WB this better. The settings in RT are excellent and really allow for correction. I may not convert the DF, as the WB seems to be an issue in UV. It seems to be unknown if the DF has the IR shutter problem, but it has the same shutter as the D800, which doesn't have an issue so I am not sure.

#2 Andrea B.

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Posted 20 August 2019 - 15:36

The Nikon Df had a nice wide dynamic range as I recall. So in that respect it would be a nice conversion.

However, I also cannot remember if the Df had the IR shutter monitor problem. You could ask Kolari or some other conversion shop about that. I'm sure they would be happy to help answer that question.

Like all other Nikon DSLRs, a converted Df will not white balance under a dark filter. For my Nikon conversions, I measure an unfiltered in-camera white balance to use for UV//IR. It cuts down on the red overload and makes it easier to set a proper exposure. Alternately, turn off false color totally and shoot in B&W. Try to place the JPG brightness histogram in the center. That usually provides a very good exposure for UV. Then false colour can be restored and white-balanced in the converter.

[[Side Note: David, what were you doing here? The UAT should show sharper than the above!]]
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#3 dabateman

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Posted 20 August 2019 - 17:41

View PostAndrea B., on 20 August 2019 - 15:36, said:

[[Side Note: David, what were you doing here? The UAT should show sharper than the above!]]

Agreed. The 800x600 down samples from Infran viewer look like trash. I will have to see what the full resolution images look like.

That said though, I remember taking the images was really hard. I had mirror lock up set. Needed a release cord to shoot, as my hand was too shaky. And had live view on to hold focus and count out how long to wait after mirror up. I focused on the eye of the cicada, and don't like the razer thin depth of field.
So I will not convert a DSLR. Far too much hassle for little benefit over my Olympus cameras.

However, if the Panasonic S1 comes down more in price. Recently dropped by $300, I may get one. It looks to have 3 stops better than my m43rds cameras and 2 stops better than the Df.

#4 dabateman

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Posted 21 August 2019 - 05:58

Andrea,

Here is 1:1 frame looking at the visible for each lens on the eye were I was focusing:

Resolve 60mm @F4:
Attached Image: DFA_4402.jpg

UAT 85mm @F8:
Attached Image: DFA_4405.jpg

The depth of field is very narrow. Why I like 43rds better, but the UAT is sharper. I also see slight shake in these images. So I may have some shutter shock issue at this magnification and with my tripod with the DF.

#5 UlfW

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Posted 21 August 2019 - 06:29

For sharpness comparison the aperture setting should be the same to get the same DOF.
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#6 dabateman

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Posted 21 August 2019 - 07:13

View PostUlfW, on 21 August 2019 - 06:29, said:

For sharpness comparison the aperture setting should be the same to get the same DOF.

Oh there is a lot more wrong with this test than just that. This was really just for me to convince myself that my EM1 and Em5mk2 are the best UV capable cameras for my photographic style.

The front of the Resolve is 8 inches away from the cicada's eye. For the UAT to be similar it has about 30mm of extension added on top of the 5mm from adapting a M42 lens to a Nikon F mount camera.
This setup was insanely sensitive to shake, air, room vibration. So I do see some image shake in these.

Also since I have taken my Resolve apart to fix an earlier issue. I don't think I properly aligned the aperture ring to the actual aperture opening. So there is a very slight shift, I also now have it really tight so its harder to adjust. I like this setting, so just keep it here. I might close it down a little more, but its a slow lens. As you can see its 2 stops slower. So I like this setting. Also the depth of field doesn't seem too far off from the UAT f8 setting. So in reality it may be closer to F8 than F4, at the approximately F4 setting. This would also make sense based on the exposure settings being identical. I highly doubt that the 4 quartz elements in the Resolve are that much less light transmitting than the quartz and florite elements in the UAT. But then I don't know the coatings. This Resolve is optimized for 254nm visualization. Whereas the UAT is 200nm to 1000nm optimized. But until Jonathan tests it on his spectrometer in December, we wouldn't know. Andy said the Resolve wasn't good in IR. So there may be some blocking.

Generally it can be seen that the UAT is sharper. But you couldn't really get an other lens like the ones Mark, Jonathan, Andy and I got, so doesn't really matter. From my discussion with the seller it seems these were slightly adjusted, cleaned and put back together. A true Resolve 60mm bought from Resolve may be much better or worst. Hard to say.

Edited by dabateman, 21 August 2019 - 07:28.


#7 Andy Perrin

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Posted 21 August 2019 - 14:26

I actually don’t know what the transmission of the Resolve is in IR. I suspect it is good. But the chromatic aberration was getting poor in visible light so I didn’t even bother to test it in IR.