Lens tests

BillN_33

BillN_33

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Bill
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I am going around in circles with fine tuning my 600mm f4 lens - I have gone from +4 to -10

all images are at high SS - 1/1250 and low ISO's ......... good tripod and all that ... and even at my age I am still quite steady!!!

I use the SpyderLenCal thing - the B & W ruler/Chart on a tripod at my normal shooting distances

They are small birds and cropped and shots at maybe 7 meters

I don't reckon any of the below are sharpe - what do you think?

the images were shot through glass ........ but I set the adjustments up outside in very good light

I have included DOF shots to try to assess the focal point - focus on the head of the bird conformed

f4 images

f4.jpg


f4_2.jpg


f4_3.jpg



f8 images



f8_3.jpg


f8_4.jpg
 
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What lens are you using?
 
Should be one of the sharpest telephotos in the range and at 7 metres there's no excuse ... have you tried Focal to remove your eyes from the equation?
Need good light though for any attempts to fine tune properly :)
 
gramps said:
Should be one of the sharpest telephotos in the range and at 7 metres there's no excuse ... have you tried Focal to remove your eyes from the equation?
Need good light though for any attempts to fine tune properly :)
Click to expand...

I have Focal ........ but I wanted to do the easy stuff first

I think that I'll stick it back to 0
 
Are you shooting everything wide open i.e.: f4 ?
I only ask as you have a very narrow dof at that focal length and aperture on Full frame ?
And I'm only guessing but you stated that you are shooting through glass which from experience can make a vast difference
A friend on mine has the same lens and he can achieve pin sharp results even hand held without it having VR
 
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i also tried this at 1250 (using a 400 + 1.4) & it wasn't until I moved the SS to about 2000 did i find consistant results on really small birds - they are just damm fast...

I also have the Focal Pro software..
 
I would sell a kidney to get my hands on a lens like that Bill ,but to then shoot through glass is totally sacrilege that's not going to help ,although I have seen some good results with your images through glass,as per Gramps It may just be you Bill,and I mean that in a nice way as you have had some consistent sharp images previously, the images look fine to me at F4 ,....change your settings not your equipment ,on a serious note Bill I think you may just be expecting to much and fussing over nothing ,but I agree that lens should produce some mighty fine images (y)
 
I have had a number of friends who have had trouble shooting or obtaining sharp images when moving up to long lens.
A simple test you can try out indoors is fit a flashgun on camera and shoot near your MFD at a object be it print or whatever you choose ? and repeat at different distances
If its sharp as it nearly always is then its down to your technique or setting that you are using in available light.
 
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I have had the lens sometime and have taken lots of shots with it - my tripod is a good CF Gitzo with the Wimberley gimbal

I produces sharpe images OOC ........ f4, f8 ... whatever

I have obviously buggered up the fine tuning

1000_1B.jpg



1000_2B.jpg


1000_3B.jpg


1000_4B.jpg


1000_5B.jpg


1000_6B.jpg



I'll look for some smaller birds
 
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I suggest you reset the micro tuning back to default and see how you get on with some outdoor shots rather than shooting through glass :)
 
Phiggys said:
I suggest you reset the micro tuning back to default and see how you get on with some outdoor shots rather than shooting through glass :)
Click to expand...

that's what I have done

Just to clear it up - I NORMALLY do not shoot through glass ........... I should know how to use the lens ........ I use it quite a lot with the TC14Elll .......

I was hoping by posting the original images someone would say that the lens is back or front focusing

as I said I took shots at both f4 and f8 .......... at a distance of 7 metres ....... I was setting the lens up to shoot through glass for a specific reason - I have just put up a feeder 7 metres from a house window in a room I sit in quite a lot when I am working on other things - it is convenient for me to use it in this way for this specific purpose.

I have taken some reasonable images in this way

All the images, bar 2, on this thread were taken in this way, (but I have only been doing this for a few days) - the images of the feeder are not mine - Simon posted those
https://www.talkphotography.co.uk/threads/a-few-tits-things.607419/

I set the feeder up last week ..... as the cold weather is approaching .. therefore an obvious reason

I will set the SyderLensCal up next to the Feeder and then shoot thru glass at it to see if I can find a setting that is better ...... that is what I am trying to achieve - an optimum setting that will be useful shooting through glass


Shooting through Glass - Obviously you need special glass but this guy is very successful using this technique in some of his bird hides

http://hidephotography.com/getpage.php?pg=one_lodge&lid=1

I indicated that I have been looking at more suitable glass to replace the existing window pain, it exists, it's not expensive and it is colourless and lets more light thru
 
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Bill after setting my fine tune i check it at different distances by placing small numbered B/W cards at different distances on short grass or even sand,both things will show you the exact area DOF is covering.
 
How expensive is this glass you're shooting through? :)

I have a suspicion that the distance from lens to glass may be rather important. My guess is the nearer the better, but try some experiments. Set up a focusing target at around average bird distance, and nearby set up a slanting metre stick or steel ribbon ruler so you can assess front or back focus. Check whether you end up at different focus points depending on whether the lens starts off from near or far focus. Take several shots at the same settings to establish consistency. Trying to calibrate exact focus with an inconsistent AF can lead to madness.
 
chris malcolm said:
How expensive is this glass you're shooting through? :)

I have a suspicion that the distance from lens to glass may be rather important. My guess is the nearer the better, but try some experiments. Set up a focusing target at around average bird distance, and nearby set up a slanting metre stick or steel ribbon ruler so you can assess front or back focus. Check whether you end up at different focus points depending on whether the lens starts off from near or far focus. Take several shots at the same settings to establish consistency. Trying to calibrate exact focus with an inconsistent AF can lead to madness.
Click to expand...

Thanks Guys

Chris - it is the normal window glass - to replace it with a good quality glass will cost about £30 a square metre, (Optiwhite made by Pilkingtons,) - I have discussed this on another thread - the window is less than a square metre.
I have tried to get the lens as near to the pane as possible whilst allowing the gimbal free movement.

I tend to test at f4 and f8 at 1/1000th sec and a low ISO - at the distance I am setting the lens up for, (in this case 7 metres), and maybe another 3 meters back, (as there are bushes at the back of the feeder), - I am aiming to have an outside and an inside setting for this lens .... because of any difference the glass would make

I use this target

chart_Adam.jpg
 
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BillN_33 said:
Thanks Guys

Chris - it is the normal window glass - to replace it with a good quality glass will cost about £30 a square metre - I have discussed this on another thread - the window is less than a square metre.
I have tried to get the lens as near to the pane as possible whilst allowing the gimbal free movement.

I tend to test at f4 and f8 at 1/1000th sec and a low ISO - at the distance I am setting the lens up for, (in this case 7 metres), and maybe another 3 meters back, (as there are bushes at the back of the feeder), - I am aiming to have an outside and an inside setting for this lens .... because of any difference the glass would make

I use this target

chart_Adam.jpg
Click to expand...

Bill.... did you use the LensCal target like this? The centre line of the pattern is supposed to continue to the '0' index of the scale. Like this the angles are incorrect giving, in effect, a parallax error.
 
chuckles said:
Bill.... did you use the LensCal target like this? The centre line of the pattern is supposed to continue to the '0' index of the scale. Like this the angles are incorrect giving, in effect, a parallax error.
Click to expand...

Well spotted Barry _ I'll check - but it does click into position so i hope not - the images are on my laptop
 
No I'm safe - I used it properly - just when I took the image for the above

here are the ones, I used

chart_Barry_1.jpg



at an adjustment of -10 ............. taken at f4 - 1/3200th sec ISO 125 ... taken outside in good natural light
chart_Barry_2.jpg


it looked OK to me - I even embossed the chart and darkened it, (as recommended by Steven)

I find it easier to read horizontally - I just flipped the vertical image to the left
 
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Ok - Just checking! Wouldn't want you to go on a wild goose-chase ;)
 
Thru the window - focus exactly on the head/eye - f7.1 - 600mm/D750

is this any sharper?

please note, these are very small birds, 4 inches including tail ........ shot from about 7 metres away
1st year juvs . so some of breast feathers will be quite soft
thru.jpg
 
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Looks better, would be good to see larger for a closer inspection :)
 
gramps said:
Looks better, would be good to see larger for a closer inspection :)
Click to expand...

It's a 1000 x 750 Roger ....... I thought that the sensible maximum for posting was 1024 anyway

This is the original, uncropped image at 2000 x 2000 - pre a few adjustments - 300k file

I'm back to +4

thru_2000.jpg
 
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BillN_33 said:
It's a 1000 x 750 Roger ....... I thought that the sensible maximum for posting was 1024 anyway

This is the original, uncropped image at 2000 x 2000 - pre a few adjustments - 300k file

I'm back to +4

thru_2000.jpg
Click to expand...

Where are you getting the measurement of 2000 x 2000 for an un-cropped image... Shouldn't it be 6016 x 4016 for a full FX file? or are you using it in DX mode or some other method??
 
Swanseajack said:
Where are you getting the measurement of 2000 x 2000 for an un-cropped image... Shouldn't it be 6016 x 4016 for a full FX file? or are you using it in DX mode or some other method??
Click to expand...

what I mean't by uncropped was that it was the FULL image ...... reduced in size to 2000 x 2000 - otherwise it would not fit on the forum ..... without moving around
 
As above 2000 x 2000 seems odd, however larger does make it a bit clearer.
It's not as good as I would expect and I'm wondering if the glass is having a greater effect than you think :)
 
Just tried the 300mm f2.8VR and the results aren't great, but it is misty

Maybe I'll open the window, (and let all my valuable heating out), and see what it's like
 
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No I won't open the window, says my wife - not on this "freezing" morning
 
BillN_33 said:
No I won't open the window, says my wife - not on this "freezing" morning
Click to expand...

Tell her "fair enough" and ask her to stand in the garden to let you try some focussing on a larger target! :exit:
 
gramps said:
Tell her "fair enough" and ask her to stand in the garden to let you try some focussing on a larger target! :exit:
Click to expand...

good job computers can't talk ......... I may get another ban
 
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Shooting through an open window of a warmer room will give even worse results than shooting through a closed window due to the thermal currents as the warm air escapes.

Best bet would be to buy a decent coat and sit outside, or better still some ODLO base layers and a decent coat
 
Or move North and find out what cold is really like.... Southern Softies ;)
 
Martyn... said:
Shooting through an open window of a warmer room will give even worse results than shooting through a closed window due to the thermal currents as the warm air escapes.

Best bet would be to buy a decent coat and sit outside, or better still some ODLO base layers and a decent coat
Click to expand...

conduction and convection ... we'll be bringing in the Gulf Stream and El Nino next ......... bird photography is never easy
 
Your biggest issue is DOF and non-stationary subjects. Combine that with the fact that AF is never 100% consistent and you are going to get some misses.

But, from what I can tell the +4 in the last image looks good.
 
Suggest you do a side by side comparison of photos of a static test target taken with and without glass in the line of sight. One of the problems with glass is multiple internal reflection, which leads to confusion at the image plane. The side by side comparison will help you to decide whether the presence of the glass is the main source of your issue, or simply one more factor.
 
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