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04-15-2014, 01:56 PM   #46
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QuoteOriginally posted by cahudson42 Quote
I usually focus on these tests using the center 'Siemens star' - getting the 'shimmer' to close in on the center circle while using focus peaking and 4x magnification
I find I get a good idea of how sharp the lens is going to be as I focus on this star. At your distance the star is resolved most of the way in and at double that distance (1metre for every 10mm of focal length) it takes a sharp lens to start the star. It is a good way to ascertain the sweet aperture spot for the lens--- focus on the star and then adjust the aperture to see how it responds. I use maximum magnification on the screen.

QuoteOriginally posted by cahudson42 Quote
I do wonder about how much variability there may be between samples
I agree and I think it applies to all lens- lessening the point of lens testing and reviews somewhat. When I get a chance I will do this test across my 5x M50/1.7 to see if I can show variation.

---------- Post added 04-16-14 at 08:57 AM ----------

QuoteOriginally posted by cahudson42 Quote
I had more light than you apparently had for your tests earlier in the thread
Do you think this makes a difference to the result?

04-15-2014, 04:19 PM   #47
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QuoteOriginally posted by GUB Quote
I find I get a good idea of how sharp the lens is going to be as I focus on this star. At your distance the star is resolved most of the way in and at double that distance (1metre for every 10mm of focal length) it takes a sharp lens to start the star. It is a good way to ascertain the sweet aperture spot for the lens--- focus on the star and then adjust the aperture to see how it responds. I use maximum magnification on the screen.


I agree and I think it applies to all lens- lessening the point of lens testing and reviews somewhat. When I get a chance I will do this test across my 5x M50/1.7 to see if I can show variation.

---------- Post added 04-16-14 at 08:57 AM ----------



Do you think this makes a difference to the result?
Hi Baz,

Last first (light) - only in that it may have made it easier for me to focus - thats it.

Re variation and 'lessening the point of testing' - I think testing every lens sold today is an 'opportunity missed'. With today's computer-controlled possibilities, including a resolution, contrast, and CA 'chart' test with every expensive supposedly high-performance (high $$$) lens would be an easy differentiation from competitors. (Unless the manufacturer is afraid what it might show...)

I seem to remember buying a rather expensive ($250 plus back then?) Makro Kilar Killfit 40mm F2.8 M42 back in the early '70s that had a strip-chart included with test results.

No reason the same could not be done today - particularly given the variation we see with your own Pentax zoom earlier up in the thread...
04-16-2014, 05:15 AM   #48
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QuoteOriginally posted by cahudson42 Quote
With GUB's nice results with his 110 lenses, I sprung for a set and the Fotodiox adapter. For comparison, here are a couple of the same setup used for the 28's and earlier 50s. They are wide open - no ring binder reinforcers yet. 18mm later.

110_50_2.8Ctr
110_50_2.8Edge
110_24_2.8Ctr
110_24_2.8Edge

Looks to me the110 50 is pretty good both Center and Edge. Not as good contrast and CA as the 50 MacroTak and Super-Tak 55 - but those were best at 5.6. Pretty sharp... No hoods either on the 110s at this point.

The 24 to me seems as sharp as the earlier FF 28s at Center. Worse than the 50 at Edge, maybe not terrible - but not great.

For $15 each, I think they can tide me over until I win the lottery for an 06.. I did buy the 18mm too, but the performance of the 02 at 15mm seems so good, I'm wondering how much I will use it - unless I need the 2.8 stop.

Really light and compact when on the Q. Even with the Fotodiox the 50 is no larger than the 02, and the 24 and 18 are smaller and shorter

Next - stopping down like GUB. I'm tempted to try back stopdown like GUB, as well as front stopdown as someone did with a lensbaby disk. Anyone with experience doing it both ways, and if so, the differences?
I use the Lensbaby aperture discs BEHIND the lens. It fits in the adapter perfectly. The 110 body had the aperture in it. This replicates it on the Q. Should have theoretical advantages.

Good testing everyone.
thanks
barondla
04-16-2014, 06:07 AM   #49
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QuoteOriginally posted by barondla Quote
I use the Lensbaby aperture discs BEHIND the lens. It fits in the adapter perfectly. The 110 body had the aperture in it. This replicates it on the Q. Should have theoretical advantages.
+1, that's what I do. I have the 110 50mm and the 70mm, and they are excellent. The set of Lensbaby discs were only $12 or something. I've also got the Soligor 1.7x 110 TC for even extra reach. Very compact setup for telephoto. The only thing I don't like is lack of mechanical shutter.

04-16-2014, 12:55 PM   #50
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lensbaby disc placement?

QuoteOriginally posted by vonBaloney Quote
+1, that's what I do. I have the 110 50mm and the 70mm, and they are excellent. The set of Lensbaby discs were only $12 or something. I've also got the Soligor 1.7x 110 TC for even extra reach. Very compact setup for telephoto. The only thing I don't like is lack of mechanical shutter.
Thank you both for the lensbaby info! Put a set on order - and yes, they are $12. (From lensbaby - plus $7 shipping) (Update: Lensbaby shipped Priority Mail 2-day. Got them today 4/18. So the $7 shipping not the ripoff I thought..)

May I ask a bit more on exactly where the lensbaby disc goes with the Fotodiox 110 adapter? Do I need to glue it or anything?

Thanks for your help...

Last edited by cahudson42; 04-18-2014 at 09:21 AM.
04-16-2014, 01:31 PM   #51
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QuoteOriginally posted by cahudson42 Quote
Thank you both for the lensbaby info! Put a set on order - and yes, they are $12. (From lensbaby - plus $7 shipping)

May I ask a bit more on exactly where the lensbaby disc goes with the Fotodiox 110 adapter? Do I need to glue it or anything?

Thanks for your help...
They have them at Adorama, etc also. Anyway, they are just fancy washers that happen to be exactly the right size -- I think they are rubber over metal as they snap in with magnets on a Lensbaby. Mount the lens on the adapter -- stick the disk in from the other side as far as it will go and it will stay snugly with a friction fit. The thing that they come in has a plastic hook or magnet to get it out again.
04-16-2014, 03:13 PM   #52
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QuoteOriginally posted by vonBaloney Quote
They have them at Adorama, etc also. Anyway, they are just fancy washers that happen to be exactly the right size -- I think they are rubber over metal as they snap in with magnets on a Lensbaby. Mount the lens on the adapter -- stick the disk in from the other side as far as it will go and it will stay snugly with a friction fit. The thing that they come in has a plastic hook or magnet to get it out again.
Remember to have them as close to the lens as possible as vignetting will progressively increase as the distance increases.
It will be interesting to see what aperture they come out at.
I doubt whether the lensbaby f rating will be correct-- if so it will be a coincidence.
I approximate my rings at f4.5 and they are about 6mm and almost on the glass.
The formula for aperture (focal length / iris diameter ) won't work here as the washers are not at the optical centre of the lens.
It seems to be f4.5 for all 3 lens - I guess they designed the lens as such coz it would make sense at the camera body end. (for metering).
If I have thought this through right the effective aperture will change if you don't consistently push the washer to the same spot.

Last edited by GUB; 04-16-2014 at 03:20 PM.
04-16-2014, 05:29 PM   #53
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Redid the 18mm,24mm and 50mm 110s to compare wide open with my stopped down modification.
Now that I am comparing results in a clinical precision environment (the kitchen bench) it appears from the shutter speeds that the ringbinder ring is dropping the light by only about 1 stop and maybe less on the 18mm. So stopped down to about f4 rather than the f4.5 I have written on the results.
The reduction in the CA by stopping down the 24 and the 50 is dramatic.
The Ringbinder ring hole is about 6mm so I am thinking you will need lensbaby washers somewhat smaller-- perhaps 2 to 4mm.

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04-16-2014, 06:00 PM   #54
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QuoteOriginally posted by vonBaloney Quote
+1, that's what I do. I have the 110 50mm and the 70mm, and they are excellent. The set of Lensbaby discs were only $12 or something. I've also got the Soligor 1.7x 110 TC for even extra reach. Very compact setup for telephoto. The only thing I don't like is lack of mechanical shutter.
Can you refer me to some shots with the Soligor 1.7x and comment on its performance?

And everyone's opinion vs. my current (flexible/changeable) Q complement?

02 - 5 -15mm
110 24mm (skipping the 18mm unless someone can give me a good reason - excepting the 2.8..)
110 50mm
M42 MacroTak 100mm
M42 135mm F3.5 (stopped down a bit)
M42 200 preset F5.6 or M42 200 F4 (heavy) - not sure yet...

Opinions always appreciated and welcome!

---------- Post added 04-16-14 at 06:08 PM ----------

QuoteOriginally posted by GUB Quote
Redid the 18mm,24mm and 50mm 110s to compare wide open with my stopped down modification.
Now that I am comparing results in a clinical precision environment (the kitchen bench) it appears from the shutter speeds that the ringbinder ring is dropping the light by only about 1 stop and maybe less on the 18mm. So stopped down to about f4 rather than the f4.5 I have written on the results.
The reduction in the CA by stopping down the 24 and the 50 is dramatic.
The Ringbinder ring hole is about 6mm so I am thinking you will need lensbaby washers somewhat smaller-- perhaps 2 to 4mm.
Really does show dramatic improvement across the board. Now for a few more of your doggie!
04-16-2014, 07:10 PM   #55
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QuoteOriginally posted by cahudson42 Quote
(skipping the 18mm unless someone can give me a good reason - excepting the 2.8..)
I think you are right in practise because of the obvious convenience of AF.
But it boils down to how good your 02 is.
Mine is well behind the 110 18mm.
https://www.pentaxforums.com/forums/136-pentax-q/209474-adapted-lenses-tested...ml#post2738293
04-16-2014, 09:09 PM   #56
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QuoteOriginally posted by GUB Quote
Remember to have them as close to the lens as possible as vignetting will progressively increase as the distance increases.
It will be interesting to see what aperture they come out at.
I doubt whether the lensbaby f rating will be correct-- if so it will be a coincidence.
No, the aperture is not correct -- you use the f/8 or f/11 disk just to get a stop down or so. It goes all the way to the bottom on the adapter right by the rear element -- basically it is in just the spot that it would be in the original 110 camera. I happen to have a lensbaby also, which did not come with all those discs, so it was a nobrainer for me...
04-16-2014, 10:37 PM   #57
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QuoteOriginally posted by vonBaloney Quote
No, the aperture is not correct -- you use the f/8 or f/11 disk just to get a stop down or so. It goes all the way to the bottom on the adapter right by the rear element -- basically it is in just the spot that it would be in the original 110 camera. I happen to have a lensbaby also, which did not come with all those discs, so it was a nobrainer for me...
Just put the calipers on the rear lens and it is about 9mm diameter. So if that is f2.8 then f4 will be just over 6mm , f5.6 will be the square root of 20 => 4.5mm and f8 the square root of 10 => 3.2mm.
(So long as it is close to the back of the lens)
04-18-2014, 12:10 PM   #58
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Lensbaby f11 & 16 disc results - 110 50mm f2.8 lens

No change in exposure until the f11 disc, placed inside Fotodiox adapter - rear, snug against a circular ridge maybe halfway toward the lens.

Exposure went from 1/320 @ ISO 200 to 1/200 @ISO 200 w/f11. So a bit less than 1 stop (right?) for it. Went to 1/100 ISO 200 with f16 disc.

50_2.8Ctr (no disc)
50_2.8Edge (no disc)
50_11Ctr
50_11Edge
50_16Ctr
50_16Edge

f11 disc seems best to me... Comments? I am using the 110 50's rubber hood. Does seem to help a bit at 2.8 on Contrast, though CA still apparent.

Next I'll compare with the 24mm...
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04-18-2014, 03:56 PM   #59
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Enlarger lens

Thought I would chuck in a couple of enlarger lens. They have done alright. Trouble is I know their weakness is a lack of lens coating when used in the field.
It will be interesting to compare the 75mm with a 110 70mm which is due to arrive.
I notice my results have softer outlines than yours Cahudson but seem to resolve the lines the same. I am saving on camera as jpg with sharpness at normal and an EV adj +1.0. and ISO125
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04-18-2014, 04:58 PM   #60
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Hi Baz,

My shots are also JPG - default whatever for the Q10. No PP. ISO 200. The setup is on a screened outside porch - screened on three sides, with the targets on a sliding glass door. (4th side). Usually mid-afternoon. No direct sunlight on the porch or targets. About 23 C today - but humid as it usually is here in Orlando, FL. My exposure is +0.3 so the shots aren't totally gray. Possibly your +1.0 is blowing things out just a bit?

I'll be very interested in your 70mm results. Here in the US they seem to have become obscenely expensive - $80 to $130, So I will be comparing to my existing 100mm Macro Tak 4.0...

Hmmmm. I do have a f1.8 85mm SMCT M42 locked away in my safe deposit box.... Could compare to the 110 70mm....

Last edited by cahudson42; 04-18-2014 at 05:18 PM.
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