Soligor Wide Auto 35mm vs Soligor KA Koyei clone

[lost cat]

In our collective neverending quest for yet more UV capable lenses I present to you a photo comparison of a Soligor Wide Auto 35mm f/3.5 lens vs a Soligor KA Kuri clone

 

Soligor Wide Auto Lens:

http://m42lens.com/m...o-35mm-f-3-5-16

 

Soligor KA:

http://m42lens.com/m...5mm-f-3-5-22-v2

 

(Galaxy version)

http://m42lens.com/m...y-35mm-f-3-5-22

 

Camera: Unmodified Nikon D40.

 

Lens Configuration: Macro configuration with an additional helicoid and/or short extension tubes to try to normalize the subject to camera distance as much as possible.

 

White balance: All photos were white balanced against a slightly defocused PFTE tape wrapped block of wood with at least three layers of tape. Visible shots with an exposure of 1/30s UV shots with an exposure of 1/8 sec. Note - the WB was performed using the in-camera "use photo" function. although no error message was generated it does not appear to have worked properly.

 

Illumination: Visible images taken with two 25W incandescent bulbs with reflectors 22 and 26cm distance from subject +/- 45 degrees from camera-to-subject plane. UV images as above but with incandescent bulbs replaced with two 26W CFL blacklight blue bulbs.

 

ISO: 400 for all imaging

 

Aperture: f/8 for all imaging

 

Shutter speed(s): 1/30s for Vis images, 1/8s-30s for UV

 

Distance to subject: 15 cm for both Soligors (flower to camera body)

 

UV Filter: Front mounted Astrodon "U" 1.25"

 

Mounts: Soligor KA has a T mount, Soligor Wide Auto has a M42 Mount

 

Filters: Soligor Wider uses a 55mm filter, Soligor KA uses a 46mm filter

Left/Top: Soligor S/N 57xxx Right/Bottom: Soligor KA

-------------------------------------------------------

Visible 1/30s:

 

UV 1/8s:

 

UV 1/4s:

 

UV 1/2s:

 

UV 1s:

 

UV 2s:

 

UV 4s:

 

UV 8s:

 

UV 15s:

 

UV 30s:

 

To my eyes the performance of the Soligor Wide Auto - at least under my testing methodology - is 1/2 stop to a stop less sensitive than the KA . Not too bad, I think this is another for the list.

[Andrea B.]

Hi Jim -

 

I'll make a blanket "Thank You" here for all your recently posted UV-capable lens tests. Thank you !!

 

These tests are useful for everyone to see how a particular lens actually records a known UV-signature.

Also, thank you for remembering to add the UV Lens tag to your posts.

 

Now where in the world did you get Dandelions this time of year? :D

I will try to get to each post separately as time permits.

 

I have this Soligor Wide Auto 35/3.5 myself. Picked up on somewhat of a whim from Ebay. I also have found it UV-capable. And a nicely made lens too.

 

One serious comment: Control your background so that it is the same in each series. And set up the still life so that there is no backlighting. There appears to be a window in the background or perhaps a doorway to another room? The ambient light from that can cause flare and alters exposure time so that the comparisons here might be faulty. Perhaps set your flowers up against a wall or shoot down on them from above, whatever works best.

 

A few thoughts about UV lens testing follow -- take these with a grain o' salt. They are just ideas and certainly not mandatory. :D I like to discuss this kind of thing with members so that we all learn, me included.

• Perhaps think about adding some outdoor views of a landscape or a street scene which would illustrate the use of these 35mm lenses as UV-capable wide-angle lenses. Granted, on a D40 the viewing angle is more like a 50mm when compared at a fixed distance, but that's still wide compared to our 105 or 135 mm UV-capable lenses.
  

• You might like to try to determine the optimal exposure at f/8 for each lens for the given scene. That can somewhat be concluded from your tests as they stand, but the red oversaturation is misleading and does obscure detail. So there is a can of worms opened up as to what might constitute "an optimal exposure" in UV? We could all figure something out, I'm sure. As an example, I sometimes shoot my UV scene at the Monochrome setting and call the exposure "optimal" when the luminance histogram comes up to but does not hit the right wall. At least with that characterization of "optimal" I can make a comparison. (Yes, I know this is the jpeg histogram, but it is all we have from the camera itself. However, see next point.)
  

• You might enjoy the RawDigger app to investigate how your lenses and camera are recording? I see that in some of the comparisons the false colour is different. I'm not entirely sure what that tells us (coatings? glass type? differing UV transmission?), but looking at the channel histograms in RD would elucidate this kind of difference. Also RD helps to determine which is the optimal exposure based on either RD's auto criteria or settings of your own choice. This kind of analysis could also be performed (I think?) using the free command-line tool DCRaw. (I haven't used it in quite a while, so I've forgotten details of its use.)
  

• You might also enjoy the Smeed Sparticle Board testing as an informal, useful indicator of lens transmission reach in the UV range.
  

[lost cat]

Hi Andrea,

 

I find the dandelions in the park by my house. Our climate allows them to grow year round.

 

Thank you for your comments and suggestions. I agree there are some improvements to be made. I plan on taking some street/nature scenes down the line but for now my goal is to come up with a reproducible way to find good UV capable lenses and be able to show relative performance between them. The sparticle board test will be useful towards that goal.

 

I have imperfect light control in the room so there is a bit of ambient visible, mostly coming from the computer I use to remotely control the camera and from small leaks around the panels and blinds I used to block the window. I need a *little* visible light to see what I'm doing after all . The Astrodon should be able to suppress any non-UV well enough under these conditions and the camera still has its original ICF to further block the low levels of NIR still remaining.

 

The door to the room is closed and there is no window. I think you are seeing the PFTE wrapped wood in the background which is making me realize the D40's in camera WB ain't working so well for UV. I can try doing a second WB on this background if you think it would be useful. I am taking all the images in RAW + JPEG so this is possible.

[Andrea B.]

It was not non-UV ambient light I was worried about. It was the possibility of ambient UV from other sources (windows, whatever) and also reflected UV off backround objects from your blacklights. As for the PTFE, you either want that object as part of the scene for comparison purposes or out of the scene altogether for aesthetic reasons. No junky backgrounds! :D

 

I think that if you do not have any white balance in your UV photos, it is perhaps better to be accurate and not claim it. As mentioned, if you have a "proper" white balance with a Nikon, Bayer-sensored dSLR, there will be no red, pink or magenta.

 

What converter/editor are you using? (Forgive me if I've asked before. I can't really keep track of everyone's software!! )

[lost cat]

It was not non-UV ambient light I was worried about. It was the possibility of ambient UV from other sources (windows, whatever) and also reflected UV off backround objects from your blacklights. As for the PTFE, you either want that object as part of the scene for comparison purposes or out of the scene altogether for aesthetic reasons. No junky backgrounds! :D

 

I think that if you do not have any white balance in your UV photos, it is perhaps better to be accurate and not claim it. As mentioned, if you have a "proper" white balance with a Nikon, Bayer-sensored dSLR, there will be no red, pink or magenta.

 

What converter/editor are you using? (Forgive me if I've asked before. I can't really keep track of everyone's software!! )

 

Well I did use the in-camera WB function and listed it as such; however i have to admit it does not seem to actually do anything. I will put that correction in my posts. I will also add a piece of black velvet to my backgrounds to keep down the reflections.

 

The JPEGs were created by the camera but the re sampling and cropping was performed using MS picture manager.

[Andrea B.]

Oh the plain wall is good enough.

Some black velvet can be kind of reflecty in UV. I tried some once and it didn't work out well. But there a lot of different kinds of fabric.

 

See other post for comment about the WB.

 

I suggest downloading Nikon's free NX-D software. It is not the greatest app in the world, but you can do a white-balance sample on it easily enough. And crop & resize.

[lost cat]

Oh the plain wall is good enough.

Some black velvet can be kind of reflecty in UV. I tried some once and it didn't work out well. But there a lot of different kinds of fabric.

 

See other post for comment about the WB.

 

I suggest downloading Nikon's free NX-D software. It is not the greatest app in the world, but you can do a white-balance sample on it easily enough. And crop & resize.

 

Already got it. Do you know if its possible to use one WB to adjust all the images or does each image need to be WB internally? So far I all I've been able to do is internal WBing.

[nfoto]

With say PhotoNinja, you can get an excellent good UV w/b from anything UV-neutral in reflectivity. A piece of white PTFE is a good choice. Then, simply copy/paste that w/b to all the image files. You will be very close to what would be the w/b for each image if set individually.

 

This of course assumes the PTFE is shot under the exact same conditions as the flower heads.

[Andrea B.]

Jim in most converters you can save a specific white balance as a preset for batch application. I don't know whether NX-D permits this. I'll have to look and see. I would think it does since it is such a common feature.

[Andrea B.]

OK, the superbowl is over. So I reviewed NX-D and found that edits can be saved two ways - in an adjustment file or as a registered item in a menu. Saved adjustments can be applied after you open an individual file in NX-D. Or they can be applied in batch mode to a selection of files made on the thumbnail page.

 

For white balance you would need to make & save a WB adjustment for each combination of camera + lens + filter + lighting. Then you could batch-apply that white balance to all the files in a series made with that combo.

 

The white balance tool in NX-D is a small, rectangular Marquee tool. Apply it to a well-illuminated, non-blown central portion of your PTFE raw photo.

 

I practiced making and saving a WB adjustment in NX-D to be sure it all really works. It does. :D

[lost cat]

How's this?

 

Left/Top: Soligor S/N 57xxx Right/Bottom: Soligor KA

-------------------------------------------------------

UV 1/8s:

 

UV 1/4s:

 

UV 1/2s:

UV 1s:

UV 2s:

UV 4s:

UV 8s:

 

UV 15s:

 

UV 30s:

[nfoto]

"How is this?"

 

Heavily biased towards excess cyan.

 

Do you have any RAW file available? I can spin it through PhotoNinja and bring out the 'true' UV false colours (now, that is an oxymoron of course :D )

[Andrea B.]

OK, more info.......

 

Your exposures at 2-seconds look fairly good. There is a bit [added later: very tiny bit] too much of an overall yellow cast in both, but you have gotten close. The exposure on the left has a tinge too much of red. That the red remains could indicate that you make the shot of the PTFE (later used to set WB in the converter) with only with one of the lenses? Or that you applied the same WB to both the left and right exposures? Each lens needs its own WB made.

 

For the record, cyan or greenish-cyan in overexposed areas is the typical expression of overexposure from the Nikon converters like NX2 or NXD (which Bjørn never uses so I don't know if he knows this?). Other converters handle overexposures in different ways.

 

Whether or not overexposured areas can be 'pulled back' depends on the amount of headroom for the camera and also depends on the converter being used and how good its highlight tool is. The D40 did not have much headroom. And with a huge overexposure like 30-seconds there would be no way to pull back the blowouts anyway.

 

However, your purpose in making an exposure-length series is exactly to see where the overexposures begin (and where the proper exposures begin). So I think we would not want to pull back overexposures in such a series.

In some converters the cyan blowout could be desaturated and that might be useful to an exposure series because viewers associate white areas with overexposure due to spectral reflections or long exposures.

Just a thought: another way to go with an exposure series is plain black & white. Avoid the false colour thing entirely and lose the distracting false colours.

 

As offered by Bjørn, if you like, put the 2-second and the 4-second exposures into Dropbox and PM us the URL. We will run them through various software and see what happens. That might perhaps be useful to you or others.

 

[[True False Colours always makes me laugh. We should write a song about that.]]

 

Here's how it would look if only the cyan/green overexposure was desatted. And if totally desatted.

[Cadmium]

Here is how I used NX-D for something similar. Simple test to compare it to CNX2.

http://www.ultravioletphotography.com/content/index.php/topic/1710-nikon-nx-d-software-test/

[lost cat]

 

As offered by Bjørn, if you like, put the 2-second and the 4-second exposures into Dropbox and PM us the URL. We will run them through various software and see what happens. That might perhaps be useful to you or others.

 

 

Done, thank you!

 

Here is how I used NX-D for something similar. Simple test to compare it to CNX2.

http://www.ultraviol...-software-test/

 

Very nice tutorial, thank you!

[Cadmium]

There are still a few of us around here using Nikon cameras for UV. ;-)

 

I usually don't use PTFE for UV white balance. You can just click around a few places to see how different points WB things, either with the plain 'eye dropper' or using the 'eye dropper' + 'left click mouse and hold to make a small square',

either will work, the square just averages more than one pixel I think.

 

I dislike cyan (almost) as much as Colin dislikes magenta :-)

[lost cat]

There are still a few of us around here using Nikon cameras for UV. ;-)

 

I usually don't use PTFE for UV white balance. You can just click around a few places to see how different points WB things, either with the plain 'eye dropper' or using the 'eye dropper' + 'left click mouse and hold to make a small square',

either will work, the square just averages more than one pixel I think.

 

I dislike cyan (almost) as much as Colin dislikes magenta :-)

 

Well my next project is to see if I can frost a pane of fused silica with 4M NaOH and if successful see how well that works as a WB reference. I read a few posts here on UVP where this is discussed as a potential solution.

[Andy Perrin]

Well my next project is to see if I can frost a pane of fused silica with 4M NaOH and if successful see how well that works as a WB reference. I read a few posts here on UVP where this is discussed as a potential solution.

OH, if that doesn't work, it's a damned lye!

[Andrea B.]

Here are the two second exposures. Thanks for letting me try this with your D40 shots. I like to keep up with how the various cameras shoot and what their raw files are like. The D40 is fine little cam.

 

Photo Ninja was able to recover the blown highlights without creating cyan discolouration using the default Color Recovery setting of 50 in the Color Correction tool. The NX2 version required some colour point work to get rid of that cyan. I've added auto white-balance renderings from Raw Digger which performs no sharpening & no noise reduction. But these serve as a sanity check for the white balance even though they are less saturated.

 

BTW, differences in global brightness and in sharpening between the PN and NX2 versions could be evened out with a little more time spent on the editing. Those differences are not the fault of either converter, just me not having time. :D

 

Soligor 35/3.5 Wide Auto :: Photo Ninja Conversion

 

Soligor 35/3.5 Wide Auto :: NX2 Conversion

 

Soligor 35/3.5 Wide Auto :: Raw Digger Auto WB

 

Soligor 35/3.5 KA :: Photo Ninja Conversion

 

Soligor 35/3.5 KA :: NX2 Conversion

 

Soligor 35/3.5 KA :: Raw Digger Auto