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05-01-2014, 12:40 PM   #91
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QuoteOriginally posted by cahudson42 Quote
Baz, to compare with others - are these at 50x (4.0 = 200lpm) or 100x? (2.0 = 200 lpm)
Your formula. 4 = 200.
But I placed the camera a measured distance away (1 metre for every 20mm of focal length) and zoomed accordingly. This is pretty well your setup but is the only way to get 2 zooms to match.So for the zooms @ 200mm I put them 10 metres from the target.

05-01-2014, 03:43 PM   #92
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What continues to amaze me is just how good the 110 lenses are on Q - even wide open and of course much better stopped down. The 110 50mm and 24mm are still around $15 to $20 here in US (fleabay), the Fotodiox adapter $20 some odd, and the ring binders ($4?) or Lensbaby disks ($12?)..

So my current Q kit is:

02 (came with it at $199)
110 24mm - f11 disc
110 50mm - f11 disc
1.7x Soligor TC
M42 135/3.5 SMCT
M42 200/5.6 preset

I do still have the Vivitar 28mm - 200mm Vivitar Kobari Beast - but I don't usually carry it around. But based on your DAL 55-300 results, I may try it at the same various focal lengths. As I remember, my initial test (above somewhere) wasn't much worse than your DAL 55-300. And its $20 or so.. in Minolta or Canon mount.Did you maybe get another bad 55-300 - again? Or is it the same one you showed earlier?

I do need to try the 110 18mm...:>)

Last edited by cahudson42; 05-01-2014 at 04:05 PM.
05-02-2014, 12:50 AM   #93
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QuoteOriginally posted by cahudson42 Quote
Did you maybe get another bad 55-300 - again? Or is it the same one you showed earlier?
Yeah it is the same sicko I tested at post 32. I wanted a more objective test at different apertures and great to have the 50-200 to compare.
Hnikesch on post 37 has a far better example. I would love to see some tests by others with it wide open though--I suspect that is the 55-300 weakness.
This test was more with my K30 in mind-- As you introduced in post 1-- the Q is a great way to stress a lens to find its weakness on other formats.
The 55-300 won't go tramping with me anymore-- the 50-200 is better all round (inc weight).
05-02-2014, 02:31 AM   #94
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QuoteOriginally posted by cahudson42 Quote
... and the ring binders ($4?) ,,,,
$4 for the hundred so that's 4 c per len

---------- Post added 05-02-14 at 09:32 PM ----------

QuoteOriginally posted by GUB Quote
.... I would love to see some tests by others with it wide open though--I suspect that is the 55-300 weakness.
....
borrow mine and see

05-02-2014, 03:19 AM   #95
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QuoteOriginally posted by Transit Quote
$4 for the hundred so that's 4 c per len
Don't forget the capital outlay of the felttip marker
05-04-2014, 06:23 AM   #96
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QuoteOriginally posted by GUB Quote
Yeah it is the same sicko I tested at post 32. I wanted a more objective test at different apertures and great to have the 50-200 to compare.
Hnikesch on post 37 has a far better example. I would love to see some tests by others with it wide open though--I suspect that is the 55-300 weakness.
This test was more with my K30 in mind-- As you introduced in post 1-- the Q is a great way to stress a lens to find its weakness on other formats.
The 55-300 won't go tramping with me anymore-- the 50-200 is better all round (inc weight).
I haven't tested the 55-300 open but see the attached link they have, quite interesting site. I mostly shoot mine Av @ f8

Pentax SMC DA 55-300mm f/4-5.8 ED - Review / Test Report - Analysis
05-04-2014, 08:22 AM   #97
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LW/PH vs lp/mm - on Q

QuoteOriginally posted by hnikesch Quote
I haven't tested the 55-300 open but see the attached link they have, quite interesting site. I mostly shoot mine Av @ f8

Pentax SMC DA 55-300mm f/4-5.8 ED - Review / Test Report - Analysis
Looks like Hans has found a great resource for info on modern Q and Q-adapted lenses. Now - can we compare - even roughly - to the lp/mm often used here for our legacy lenses?

When I started looking for a test model, I found Atkin's stuff easy to understand - as I was brought up on the USAF charts in lp/mm (Line Pair/ Millimeter). Now the modern way - as used in Photozone - is apparently LW/PH - Line Widths/Picture Height.

So how to convert? (please correct if in error!) Good Q lens results in LW/PH seems to range around 1500 - 2300. Lets take 2000 LW/PH. Now the Q sensor is 4.55mm in Height:
.
2000/4.55 = 440 lines (not line pairs) per mm. To get line pairs/mm - divide again by 2. Equals 220 lp/mm. So roughly 10:1. Or easier to do in your head maybe - take a Photozone Q test LW/PH, take a 1/10 (shift decimal 1) and add 10% and you have the equivalent on lp/mm as we have been using here.

We are often seeing center lens results on some legacy lens - like the 110 50mm f2.8 with stop down - easily resolving the 4.0 lp/mm Atkins test chart bars. At 50X (in retrospect, GUBS 100X probably would have been a better choice) thats 200 lp/mm - or 1800 or so LW/PH. (Photozone 01 test LW/PH = 1800+)

Anyway, GUB's DA 55-300mm does seem a dog. I'm still thinking something inside has shifted or come loose to make it test that bad...

Last edited by cahudson42; 05-04-2014 at 07:13 PM.
05-04-2014, 08:47 AM   #98
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QuoteOriginally posted by cahudson42 Quote
GUB's DA 55-300mm does seem a dog. I'm still thinking something inside has shifted or come loose to make it test that bad...
Agree. Have shot different copies of this lens- none looked like this. Send that baby into Pentax for a checkup/ surgery.
thanks
barondla

Enter the Point & Shoot photo contest in the Compact Camera forum. The Q is invited. Show what you can do with the Q! Open theme. Enter what you want. Just enter.

05-04-2014, 02:50 PM   #99
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QuoteOriginally posted by barondla Quote
Agree. Have shot different copies of this lens- none looked like this. Send that baby into Pentax for a checkup/ surgery.
thanks
barondla

Enter the Point & Shoot photo contest in the Compact Camera forum. The Q is invited. Show what you can do with the Q! Open theme. Enter what you want. Just enter.
Yes my lens is a sicko without doubt.
And I find this thread interesting-- https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/153917-da-55-300-issue.html
It describes my lens perfectly. And I am a tramper (That is NZ for trekker?) That lens has been packed through some rugged country and probably knocked around.
Maybe it is time for some kitchen table open surgery
But the 55-300 doesn't actually come out too flash on that photozone site when compared to others.
If I was in the market for a longer zoom it would not be my choice after doing a bit of research.

It has redeeming qualities though-- there is an art in it that sometimes works.
Attached Images
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PENTAX K-30  Photo 
05-04-2014, 06:13 PM   #100
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QuoteOriginally posted by GUB Quote
Don't forget the capital outlay of the felttip marker
I flogged it from the missus

---------- Post added 05-05-14 at 01:15 PM ----------

QuoteOriginally posted by GUB Quote
....

It has redeeming qualities though-- there is an art in it that sometimes works.
lovely colours, would look good on the wall. The fuzzy hardly matters there
05-04-2014, 06:29 PM   #101
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Sort of like a picture entirely made of bokeh
05-04-2014, 07:08 PM   #102
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GUB, there is something drastically wrong with your lens, just send it in for repair. Here are a couple samples from mine. Both shot at 300 mm. I don't have a Q adaptor yet so I can't tell you how that would work. These two are from the K5.



05-04-2014, 07:31 PM   #103
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QuoteOriginally posted by Heinrich Lohmann Quote
GUB, there is something drastically wrong with your lens, just send it in for repair. Here are a couple samples from mine. Both shot at 300 mm. I don't have a Q adaptor yet so I can't tell you how that would work. These two are from the K5.


I don,t think that is really an option over here in NZ.
What say you fellow kiwi -- Transit
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