a few lenses tested in UV

[Fandyus]

I decided to test a few of my lenses by simply shooting a PTFE sheet and observing the shift in color balance. It was fully overcast. The exposure time and iso is the same for all images in order to demonstrate the differences in maximum possible exposure. All of the lenses are shot at their respective brightest apertures. The left column images all have the same color balance, that being color balance of the PTFE sheet shot with the Soligor. The right images are with color balance turned off.

Lenses tested:

Soligor 35mm f/3.5 (still the best)

Industar 50-2 (not the best but way sharper)

Domiplan 50mm f/2.8 (had high hopes for this one but unfortunately it's mediocre)

SMC Macro-Takumar 50mm f/4 (unsurprisingly the worst of all for UV)

Carenar 35mm f/3.5 (got this lens for dirt cheap, works well enough I suppose)

Might test a few more sometime later.

[nfoto]

Did you alter the exposure time to adjust for the differences in lens "speed"? It would be unsurprising to find f/2.8 lenses the brightest and f/4 the darkest, when using the same shutter speed.

 

Alternatively, you might set all lenses to as common f-number, say f/5.6. It would be a test for UV response not necessarily sharpness. Most non-special lenses for UV tend to require stopping down -- a lot -- for best results in terms of image sharpness.

[Fandyus]

7 minutes ago, nfoto said:

Did you alter the exposure time to adjust for the differences in lens "speed"? It would be unsurprising to find f/2.8 lenses the brightest and f/4 the darkest, when using the same shutter speed.

 

Alternatively, you might set all lenses to as common f-number, say f/5.6. It would be a test for UV response not necessarily sharpness. Most non-special lenses for UV tend to require stopping down -- a lot -- for best results in terms of image sharpness.

I have said that all the lenses were shot at their respective brightest apertures. I can't stop down the Domiplan so that's why. One could work out the relative brightness of each of the lenses by adjusting the images according to what the brightest aperture of each lens is.

[Doug A]

Interesting test. Not surprised the macro lens did the worst. 

Thanks for sharing,

Doug A

[ulf]

6 hours ago, Doug A said:

Interesting test. Not surprised the macro lens did the worst. 

Thanks for sharing,

Doug A

That is the later model with a good UV-blocking coating.

Some say that it is good as a VIS macro lens so maybe it is usable for UVIVF.