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Some very basic lens test with ? dandelion

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#1 Jim Lloyd

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Posted 09 March 2018 - 18:39

Hi All,

Taking some very first crude steps to testing and comparing the various lenses I have purchased to date - feedback and advice welcomed.

I have done several experiments with visible light to compare lens sharpness and will show those later, but today I spotted a flower that might be useful so I did a number of tests to see the UV characteristics.

Attached Image: Capture multi lens comp.JPG

The lenses are:
Soligor 28 mm f/2.8
Photax 28 mm f/2.8
Optomax 35mm f/3.5
Nikon E series 50 mm f/1.8
Samuron 135 mm f/3.5
Nikkor AF f/2.8 D
Nikon kit lens supplied with D40 and D3300

Camera full spectrum modified Nikon D3200
UG1 2mm +BG40 2mm filters
ASA 200
4 second exposure
Sunlight outdoors

Flower - ? like a Dandelion, but smaller - about 1 inch (2.5 cm) diameter. This is something that is very common and grows like a weed around here, but I was surprised to see it flowering this time of year.
And snowdrop in some of the photos

My question really is, is this a good test of the lenses UV capability?
How do I choose between them?
I guess I am looking for a dark centre - so really most on the top row look OK - possibly Optomax the best?
The Nikkor lens is quite expensive with good quality coating so this would be as expected from a lens without UV capability?

I would be interested in any thoughts

#2 Andrea B.

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Posted 09 March 2018 - 20:14

Tussilago farfara [Colt's Foot]

As you can see from the link, this tough little flower has very black center disk florets making a dark bull's-eye in reflected UV. And there is a fainter dark ring on the ray ends which circles the disk. Any camera and lens combo which shows that clearly is good. So, yes, I'd say the top row lenses best capture this. Hard to say with just one example (and small photos) which is best. Typically we have found that the 35mm f/3.5 lens class contains some good-to-excellent UV-capable lenses because of the way (most of) these lenses are constructed with a small number of elements and lack of coatings. I think that Enrico Savazzi has written about the Optomax. You might want to check his website if you haven't already.

And, yes, shooting a known UV-signature is a good test of the len's UV-capability. But remember that lenses have other characteristics to test for: sharpness, color aberrations, corner softness, rendering of detail, contrast -- to mention a few.
Like, for example, you can find industrial lenses which pass UV at 90% but when used under a broadband UV-pass filter the color aberrations might ruin sharpness and obscure some details. So simply passing enough UV might not make a lens fully qualified. Of course, for us UV shooters, that is the place we have to start. "-)

(What are the Nikon kit lenses? Zooms? or what? I have no idea.)
Andrea G. Blum
Often found hanging out with flowers & bees.

#3 Jim Lloyd

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Posted 09 March 2018 - 22:14

Thanks Andrea. Yes I will come on to comparisons of sharpness etc later.

By "kit lens" I mean the ones that are normally sold with the camera - AF-S Nikkor 18-55 mm 1:3.5-5.6 GII VR - for the D3300 - For the D40 its a similar earlier version of the same lens without the VR (Vibration reduction)

#4 Jim Lloyd

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Posted 09 March 2018 - 22:52

Soligor 35mm f/3.5 (s/n 9711108) (£5 ebay) vs Optomax 35 mm f/3.5 (s/n 36766) (£25 ebay)
To test I used Nikon D610 full frame and compared against Sigma 35mm f/1.4 (cost ~ £500) - photographed newspaper and landscape.

Both are T-mount - fits to Nikon F mount using adapter

Optomax has pre-set aperture which is useful, except the main aperture ring is faulty and doesn't click into place
6 blades
Focus ring moves well and has nice feel.
Close focus about 60 cm

Soligor focus ring slips a bit
Aperture clicks into place fine - 8 blades
For some reason when connected with adapter lens is upside down - i.e. the aperatire and focus markings are on underneath.
Close focus 80 cm

In newspaper test the Sigma lens is sharp across the full frame and at all apertures

Optomax lens at edges (of full frame) is very blurred at f/4 and only really acceptable at f/11 and f/16, but in the centre look OK from f/5.6-f/22
Soligor is similar to Optomax, except only acceptable at edge at f/8 - f/11 and in centre f/3.5 - f/11
Side by side comparison - Optomax looks "brighter" than Soligor

For landscape when cropping the centre from the full frame (DX crop) at f/11 and f/8 the Optomax is difficult to distinguish from the Sigma
The Soligor has a different look - softer, "older" ? warmer ? more character
The Optomax appears to have reasonable UV performance based on the above. For some reason I had trouble doing white balance with the Soligor lens (might have been my mistake).

Conclusion - probably will bin the Soligor lens!
The Optomax is a good lens for landscape best at around f/11or f/16 - at f/11 focus at 18 ft gives focal depth 9 ft - infinity. The preset aperture is useful in Live view as you can open up to focus and then quickly stop down.

For example comparison below (hope this is useful / interesting - I know a lot has been written on these lenses, but I have found it helpful to do my own tests)

Attached Image: optomax corner.jpg

Attached Image: soligor v optomax f11.JPG

Attached Image: soligor 35 corner.jpg

Centre crop from left to right, Soligor, Optomax, Sigma


Attached Image: landscape.JPG

DX crop left Soligor, right Optomax

Attached Image: landscape compare DX crop.JPG

Edited by Jim Lloyd, 09 March 2018 - 23:03.


#5 Andrea B.

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Posted 09 March 2018 - 23:15

Good testing!

I know a lot has been written on these lenses, but I have found it helpful to do my own tests.
I've also always felt that to be helpful (maybe mandatory?). There can be quite a bit of sample variation especially as the lenses age and begin to fall slightly out-of-spec from wear-and-tear or lack of maintenance.

What you mention about character is also important. Could be that a lens is terrible for close work but produces a nice dreamy landscape. There's probably some use for every lens if only we can find it. :)
(Like they say, there's a chair for every butt. Oh dear, can I say that here??)


There are some pretty serious color aberrations going on with that Soligor. That's probably why the white balance did not work out well?? Not nearly as much seen with the Optomax. Interesting.
Andrea G. Blum
Often found hanging out with flowers & bees.

#6 Cadmium

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Posted 10 March 2018 - 01:06

Jim, which do you like best?
That 50mm E lens looks best to me, but hard to say.
You don't have an El-Nikkor 80mm? One of those would be good, although it doesn't have focus, so you would need a helicoid for it.
I prefer the shots that include some of the foliage, it helps to compare.

Edited by Cadmium, 10 March 2018 - 03:20.


#7 Jim Lloyd

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Posted 10 March 2018 - 12:13

Thanks Andrea and Steve

A bit more testing this morning comparing Soligor 35 and Optomax 35 - this time it is dull and rainy outside, but with a long exposure indoors in front of window I was able to get a similar image for the Optomax compared to outdoors in bright sun yesterday. This is useful to know as I assume it shows that the window glass is not a limiting factor in this case.

Also I was able to get a very similar UV image with the Soligor to the Optomax. I think yesterday I accidentally had the Soligor wide open as the preset aperture ring was in the wrong position - leading to serious overexposure.

Something else I noticed was that in these low light conditions it was much easier to view the Live view screen with the Optomax compared to the Soligor (both fully open). I don't understand why this is as I would have thought both should be admitting the same amount of light. I do note that the diameter of the front glass is smaller with the Soligor (about 22 mm) compared to the Optomax (about 28 mm) and the Soligor has a very slightly brownish tinge when you look through it at a white surface. I am trying to think of some reason to keep the Soligor, but its future is looking bleak at the moment! Rather wish the Optomax was in better shape physically because it does have some merit.

Steve - I am not sure which I like best at the moment. I am trying to eliminate some so I can do some better testing on the others. The Nikon E 50 certainly is a nice lens with a good feel and the example I have is in very good condition. I don't have a Nikkor 80 - is that an enlarger lens? Are these easy to obtain and is the helicoid easy to get and fit?

#8 UlfW

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Posted 10 March 2018 - 13:36

The EL-Nikkor 80/5.6 old metal version is not unusual to be found on eBay worldwide.
Search for "EL-Nikkor 80".

It is a quite good enlarger lens with very nice UV-performance and only very little focus-shift in UV-Vis-NIR.
Highly recommended.
Last summer it was my main UV-lens and I am very pleased with the results.

The lens mounting thread is M39.
Step up rings helicoids and extension tubes for the more common M42 are easy to find.

One minor problem to overcome is that the front filter thread is quite unusual, M34.5 pitch 0.5mm.
The brutal solution can be to get a cheap step up ring M34 - M52 and hot-melt glue that to the front of the lens.
The elegant more expensive solution is to buy one with correct threads. Search for "step up ring el-nikkors"

If you want to be able to focus all the way from quite close-up to infinity, please see how I solved that for my EL-Nikkor 80 here:
http://www.ultraviol...__fromsearch__1
I use a Canon EOS with a different back flange distance than Nikon and helicoid design differ but the principle will work well for a Nikon camera too.

Edited by UlfW, 10 March 2018 - 13:49.

Ulf Wilhelmson
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#9 Jim Lloyd

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Posted 10 March 2018 - 14:52

Thanks Ulf

Would this one be suitable - or does it have to be an older version like this ?

I also see that there are quite a few other focal lengths available (50,75,105,135) and various maximum apertures. Do you have any advice on these?

Many thanks

#10 UlfW

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Posted 10 March 2018 - 15:40

Hi Jim,

Both are suitable.
My first one was of the oldest, Nippon Kogaku-type.

When I saw the lightly newer version I couldn't resist the low price.
Both work well and measure the same bandwidth in my spectrometer.

The later plastic case types are supposed to perform worse due to a newer type of coating. I have never tried that version

I have 50/2.8 old, 50/2.8n, 2 x 80/5.6, 105/5.6 and 135/5.6
Bitten by the collecting bug. :-)

The 80mm is #1for UV, closely followed by the 105mm.
I think the 105 has worse focus shift.

I got most of these lenses too late to try them properly on the camera, but I have measured the UV-cutoff with my spectrometer.
The results for 50/2.8 old and 135/5.6 as UV-lenses is not that promising, but they are still somewhat usable.
These two have a cutoff-wavelength (50%) around 365-375nm if I remember correctly.


Edit: Typo.

Edited by UlfW, 10 March 2018 - 17:09.

Ulf Wilhelmson
Curious and trying to see the invisible.

#11 Andy Perrin

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Posted 10 March 2018 - 16:26

You can buy a step ring of the correct thread and size for EL-Nikkors from this place:
https://www.rafcamer...hread/m34-5x0-5

(That's where I got mine. They take a long time to get to the US, so you may want to pick out all the ones you want and buy them in one order.)

Edited by Andy Perrin, 10 March 2018 - 16:26.


#12 Andy Perrin

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Posted 10 March 2018 - 16:28

View PostUlfW, on 10 March 2018 - 15:40, said:

They all have a cutoff-wavelength (50%) around 365-375nm if I remember correctly.
Not sure which ones you meant here? I'm pretty sure that the 80mm/5.6 metal version cuts off at close to 320nm from Klaus's tests?

#13 UlfW

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Posted 10 March 2018 - 17:09

View PostAndy Perrin, on 10 March 2018 - 16:28, said:

Not sure which ones you meant here? I'm pretty sure that the 80mm/5.6 metal version cuts off at close to 320nm from Klaus's tests?

Typo of mine. "They all" should have been "these two" meaning the 50/2.8 old and 135/5.6 (corrected above now)

Klaus has used 25% as transition level when stating cutoff wavelengths on many places, not as I expected 50%.
His spectrograms do not have much of a wavelength grid so it is difficult to read the proper wavelengths and compare with the numerical statements.
As he refuses to reveal any of his methods it is difficult to verify how correct they are.
There are also other details in his spectrograms that make me wonder a bit about his measurement methods.

The 80mm/5.6 metal version actually cuts off ("50%) at close to 340nm if I remember correctly.

If of interest, I can do measurements of these EL-Nikkor lenses and describe the methods and weaknesses in the result, as I see them.

It might take a few weeks as I am awaiting a new better light-source for my setup.
Ulf Wilhelmson
Curious and trying to see the invisible.

#14 UlfW

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Posted 10 March 2018 - 17:14

View PostAndy Perrin, on 10 March 2018 - 16:26, said:

You can buy a step ring of the correct thread and size for EL-Nikkors from this place:
https://www.rafcamer...hread/m34-5x0-5

(That's where I got mine. They take a long time to get to the US, so you may want to pick out all the ones you want and buy them in one order.)

This is the seller you find if you do the Search for "step up ring el-nikkors" on eBay.

Last time I bought from them via eBay I got the ring quickly.
It might be quicker to the EU.
I think Jim is on this side of the Atlantic just as I am.

Unfortunately the need for exotic steep-rings is very difficult to predict.
There is always one missing.

Edited by UlfW, 10 March 2018 - 17:18.

Ulf Wilhelmson
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#15 Andy Perrin

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Posted 10 March 2018 - 17:40

View PostUlfW, on 10 March 2018 - 17:09, said:

Typo of mine. "They all" should have been "these two" meaning the 50/2.8 old and 135/5.6 (corrected above now)

Klaus has used 25% as transition level when stating cutoff wavelengths on many places, not as I expected 50%.
His spectrograms do not have much of a wavelength grid so it is difficult to read the proper wavelengths and compare with the numerical statements.
As he refuses to reveal any of his methods it is difficult to verify how correct they are.
There are also other details in his spectrograms that make me wonder a bit about his measurement methods.

The 80mm/5.6 metal version actually cuts off ("50%) at close to 340nm if I remember correctly.

If of interest, I can do measurements of these EL-Nikkor lenses and describe the methods and weaknesses in the result, as I see them.

It might take a few weeks as I am awaiting a new better light-source for my setup.
More measurements are always good. There is nothing wrong about using 50% or 25% as your benchmark so long as you say which. However, my comment was based on eyeballing the graph, actually, and while based on his graph, it was my statement not his. We tend to push our equipment to the edge around here, and while a 50% mark is standard in most fields, I would say it is still useable out past 340nm with appropriate narrow bandpass filters? Anyway, I have digitized Klaus's data from the graph using my GraphClick program, which is accurate to within 1% or so. I get 341nm as the 50% cutoff, and 327nm for 25%.

Edited by Andy Perrin, 10 March 2018 - 17:43.


#16 Cadmium

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Posted 10 March 2018 - 18:26

eBay item number: 142384077655
M34.5x0.5 to M52x0.75 filter step-up ring for El-Nikkors
rafcamera
https://i.ebayimg.co...n-q/s-l1600.jpg

#17 Jim Lloyd

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Posted 10 March 2018 - 18:30

Thanks Ulf and Andy - I have ordered the EL-Nikkor 80 mm f/5.6 listed above from ebay. I will look into the various adapters shortly.

Continuing my lens evaluation I have looked at the two 28 mm lens I have:

Photax paragon 28 mm f/2.8 No 332578 (ebay £50)
Soligor wide auto 28 mm f/2.8 No 17304858 (ebay £40)

Test shots of newspaper shows both lenses to have sharp central focus at f/8 - falling off at larger and smaller apertures and at edges with noticable vignetting at larger apertures on full frame
Side by side there is little to choose in terms of sharpness, but I think I prefer the Soligor.

Both have quite short close focus about 30 cm subject to focal plane - Soligor slightly shorter than Paragon

Both look and feel good - slight preference for feel of Soligor. Aperture ring moves in half stops.

On Nikon D610 you can input non-cpu data and then the Soligor aperture stops are recognized and camera metering works in AP mode. This doesn't work for the Paragon - Can't be done for either lens with D3200 camera.

For landscapes (using D3300) both produce nice images, although there is noticeable softness and chromatic aberration at the edges - the later can be corrected to some extent in Lightroom.

The previously mentioned Optomax 35 mm is much better for landscape in this respect, although I prefer the width of 28 mm

On quick test above both lenses appear similar with regards to UV performance.

Conclusion - both lenses are similar, although Soligor just edges it. Paragon is surplus to requirement and I may re-sell on ebay.

Here are some landscape examples (visible only). First one Paragon, others Soligor.

Attached Image: 28 test.jpg

Attached Image: 28 test-4.jpg

Attached Image: 28 test-7.jpg

Attached Image: 28 test-5.jpg

#18 UlfW

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Posted 10 March 2018 - 19:01

I agree that a different reference level can be OK, but only if you include what level is used, otherwise you create confusion.
It is better for clarity to use the more common 50%

I think that Klaus too has stated that the EL-Nikkor 80 has a cutoff of 320nm, but I think not always stated that the 25% level was used.
Sometimes he has defined the used level. If I remember correctly I have seen it in a post at Fotozones.

I also agree that there might be usable image information past 340nm for this lens, in some situations.
My main problem here is that when we compare cutoff-wavelengths between lenses stating wavelength values, the same reference levels must be used.

I assume that you used the maximum transmission level at ca 90% and then the 45% as the half level when using your GraphClick in Klaus's data.

Edited by UlfW, 10 March 2018 - 19:05.

Ulf Wilhelmson
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#19 Andy Perrin

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Posted 10 March 2018 - 19:45

No, I'm not using the percent of the maximum transmission percent, I'm using the 50% transmission point itself. (Otherwise you have to decide where is the maximum.)

45% transmission corresponds to 337 nm, and
22.5% transmission corresponds to 326 nm

Edited by Andy Perrin, 10 March 2018 - 19:51.


#20 Cadmium

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Posted 11 March 2018 - 04:58

My favorite lens for UV is still the Kuribayashi 35mm f/3.5, which is simply an alternate branded version of the Kyoei 35mm f/3.5., identical except the focus ring cosmetics.
The Kuri is made by Kyoei.
http://www.ultraviol...__fromsearch__1

Don't get thew wrong one!
Kyoei makes another style of 35mm f/3.5, the one on the left hand side in this photo, and it doesn't transmit UV very well.
Attached Image: Kuri_Kyoei_Petri_4_lenses_A_1280b.jpg

Attached Image: Kuri_Kyoei_Petri_4_lenses_B_1280.jpg

These have deep UV transmission, better than El-Nikkor 80mm, or Noflexar 35mm. It has almost no focal shift. It has built in focus.
The Kuri and Kyoei are a little hard to find sometimes, but if you can find one, then get it.
Don't get one that is advertised as a 'clone' or 'variant', get the real thing if you can find one, then you don't need to wonder, and you won't need to compare.
The Kuri's are all M42 threaded mounts, the Kyoei's are found in M42 and some other mounts. Best to get M42.
For infinity focus on a Nikon, you will need a 'cheap' M42 to Nikon adapter that has a built in infinity focus lens (such as this one in the link below), which can probably be found even cheaper on eBay.
The key word here is 'cheap', because the more expensive versions of these will probably have coatings, and the cheap ones are made out of simple BK7 glass (or the like) which transmit UV as good or better than the lens. This is also true of most cheap close up filters filters (+1, +2, +4, and +10 strength).
I post this link as an example, it looks like mine, and I got mine there.
https://www.bhphotov...mount_lens.html

I can't recommend the exact adapter in the link above, because I have not tested it.
Actually, here is a pic of the exact infinity focus M42 to Nikon adapter I use with my Kuri.
Attached Image: BOWER_NIKON_M42_Infinity_both_sides_1024.jpg

You can also get a simple M42 to Nikon adapter with no infinity lens for closer work.
Similar to this:
https://www.bhphotov...crew_mount.html

Edited by Cadmium, 11 March 2018 - 05:28.