Experiment with my new Marumi +3 Achromatic Filter (or technically lens)

[Jim A]

I decided to do an experiment with my new Marumi +3 achromatic filter. I used a constant f8 stop, had the camera on a tripod (with image stabilisation switched off) and used a wireless remote. I used live view and manual focusing. The subject was about 95-120mms away from the front of the lens. The photos were taken in RAW and then had a little post production done to each identically in Lightroom.

Image 01 - Sigma 17 - 70 lens at 70mms with Achromatic filter

Image 02 - Sigma 17 - 70 lens at 70mms without Achromatic filter

Image 03 - Nikkor 18- 300 lens at 100mms with Achromatic filter

Image 04 - Nikkor 18- 300 lens at 200mms with Achromatic filter

Image 05 - Nikkor 18- 300 lens at 300mms with Achromatic filter

Image 06 - Nikkor 18- 300 lens at 300mms without Achromatic filter

Image 07 - Nikkor 18- 300 lens at 200mms without Achromatic filter

Image 08 - Nikkor 18- 300 lens at 100mms without Achromatic filter

I must admit to some disappointment in the filter so far, but am somewhat philosophical because it may be the way I have conducted my experiment and my distance etc. Any comments or assistance would be most welcome!

[Jim A]

My upload of the images keeps on failing again and again. I have made the mistake in the past of having the images too big, however these certainly are not! They are JPEG's 1000 wide and 667deep. The first is 261Kb and I realise that I can only upload one at a time. Something wrong happening at the website??

[Jim A]

First one from Flickr - Not sure whether to continue, this has turned into a major exercise - it seems even from Flickr that I have to deal with each image separately - life is so short

https://www.flickr.com/photos/277601...posted-public/

[george013]

Go to your Flickr picture, click click the download arrow right under, select "view all sizes", select the desired size, stand on the picture with the mouse, right click, select "copy image location". Go back to the edit window of this forum, select "insert image" and past the image location. Only the original contains exif.


If you read this I'll delete this image. There is another way to.




If you don't want the image shown directly, just past the image location in the editor directly.
https://c1.staticflickr.com/5/4346/3...f6799ff9_z.jpg


George

[John 2]

Alternatively, check out the contribution from Randy and Mike Buckley here:

Tinypic

[DanK]

I'd be curious to see the images.

I always link to my website (Smugmug), which is very simple: select an image, select a size (I generally select about 1000 across), copy the link, and paste it here using the "insert image" icon. However, that does have to be done one image at a time.

[Jim A]

Thanks for the suggestions, everyone. I should have used my Flickr account at the start. Anyway here is a link for the first image and the rest can be followed on Flickr from there. I will keep in mind about the info on your link John. I have a very few images on Dropbox at present.

https://www.flickr.com/photos/277601...posted-public/

[DanK]

There isn't enough information for me to be confident, but this looks like a simple DOF issue to me. It looks like the plate isn't parallel to the sensor, and in each photo, one area is sharp, while another that is either closer or farther away from the camera isn't. That looks like narrow DOF.

How large is the portion of the plate in the photo? What is the distance from the front to the back of the photographed portion?

I don't know what level of magnification you are getting with that combination of lens and adapter, but I'm guessing that the it gives you very narrow DOF, as you would get with a dedicated macro lens.

To test sharpness at macro distances, the best thing is to hang a target vertically and shoot directly at it, so that you are not confounding DOF issues with sharpness.

[Stagecoach]

I must admit to some disappointment in the filter so far,

Jim, what exactly are you disappointed with? Is it IQ or magnification?

but am somewhat philosophical because it may be the way I have conducted my experiment and my distance etc. Any comments or assistance would be most welcome!

An answer to the above (what your disappointment is) will allow more help.


But so far, I agree with Dan.

Looking at the results against the listing all the results appear to show is that the focus plane has shifted in each shot.

What is 'sharpest' at the focal plane I would say appears equally as sharp in each image at the captured focal plane, taking account of viewing at these small sizes.

[Jim A]

Thanks Grahame & Dan - It is the magnification, which does not seem much at all, I was expecting a more dramatic result.