TCs - 1.4x, 1.7x and 2x (MICRO ADJUSTMENT)

[I4ani]

Has anyone with a modern DSLR which has micro focus adjustment (such as a D300 or D3), carried out any testing with 300,400,500 or 600 lenses, to establish if there is any improvement with TCs after adjustment?

regards I4ani

[Watts]

I have adjusted for use of 1.4 with 500 on the D300. It seems to make a difference.

Bill

[Chalky W]

Hi, forgive my ignorance but can I ask what is 'micro focus adjustment'? I'm a D300 user with a Sigma 500 and a 1.4tc and am wondering if it's something I've missed as I've not heard the term before. Any explanation would be appreciated.

Thanks

[Derry]

on your D300 menu screen go to the wrench and scan down to the AF Fine tune and click OK,, will take you to the setting ability to adjust the lens presently on the camera to move the focus point forward or backward in small increments,, you do need some form of test chart for comparisons,,

I have a line test chart and you can really see what the impact is when you make an adjustment and then review it at 200%,, it is not the 45 degree shot that many use but a full screen with lines,, really shows any weak areas on the lens,,

I tested my 70-200 VR and both ends of focus, the middle, at various f stops and moved the range from a -10 to a +10,, after reviewing all the photos a +5 was the best and noticeably improved over the 0 default,, all viewing of test comparisons was done at 200%,,

have not had the opportunity to test out longer lens but it certainly is worth the 30 minutes to assure every lens is offering as sharp a photo as it can provide,,

my next testing will be with the new TC1.7 on the 70-200 and see if any improvement is offered by the fine tunning adjustment,,

have posted below one of the line charts I use,,

Derry

[seaspirit]

Focus Microadjustment is intended to compensate for slight front or backfocus that one may (most likely) has with various lenses. Nikon only offers it in the higher end bodies (> D300) and you will find the way to do it in the camera's manual (surprise) and google will turn up a couple of suggestions how to do it best (for me bar codes on high quality book covers worked, i.e. good crisp print quality).
I did it for all my lenses on the D300 and all came out improved, especially when a TC was attached.
Note! You will have to store settings for lens + TC as a separate lens. For my stuff the compensation value for each lens with TC was pretty much the same as without, but this value has to be entered and stored for the combo.

Ulli

[I4ani]

Thanks for the comments Watts/Derry/Seaspirit.

I carried out a micro adjustment on the following 3 lenses (300/2.8VR;500/4ASF2 and 600/4VR) with a nikkor 1.4tc several months back.
I used a high grade 1 metre rule graduated in mm, and set at 45 degrees.At the 50 cm mark I also added some bar codes and a clearly defined sentence of about 10 words spaced equally either side of the 50 cm mark.Test were carried out at min focus and max f number for each lens.
The 1.4 tc is highly rated by many users, but I wanted to see if there were any improvements on the above lenses, as I was not quite happy with it on the 600/4.
The 300 with tc gave excellent results, and micro adjustment +or- did not appear to improve on the 0 setting.
The 500 needed a slight adjustment of -5, and the 600 went to -10, both these settings gave a very obvious improvement.
My point for the post was to see if anyone else had done any tests, as many tcs come in for bad press, and it may be that, where cameras permit a simply tweek can make a great difference.
There are many opinions on tcs on this forum, and had I been asked if the 1.4tc was good, then based on the 300/2.8 lens I would have said it was great, but on the 600/4 it was not so good until after the adjustment.
I think Yossi, on the 1.7tc thread has made similar comments regarding this tc on different lenses.
Oh well, better get out the old 2x tc and see if it was really as bad as I used to think.
regards I4ani.

[Ian Hardy]

Hi Derry,

Can you please explain comparisons at 200%?

Thanks

Ian

[Duke Leto]

open up an image in ps or the like and view at 200%

[Derry]

Ian, as Duke indicated when you have a photo open there should be somewhere on your screen indicating at what magnification level you are viewing the photo at or zoomed in,,

when I indicate viewed at 200% this means the original photos size has been enlarged 200%,,

what software are you using,,??

Derry

[Ian Hardy]

Steve and Derry,

Thanks i will sort my 400mm f2.8 VR Lens, i am using Photoshop CS3 .

Ian

[Duke Leto]

there is a strong likelyhood that nothing will need sorting, I haven't had to do any adjustments with my lens / body combo

[Derry]

Ian see my post in the TC1.7 discussion on how to validate your lens,,

certainly well worth the time to see if you can obtain any increase in resolution,, ya never know till you do the test and see,,:t:

Derry