MTF mapper

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

Moderators: Chris S., Pau, rjlittlefield, ChrisR

Adalbert
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Post by Adalbert »

Hello Smokedaddy,
Probably the black diamond at the bottom of the following slide would be better:
https://www.ebay.com/itm/Microscope-Eye ... 0753.m4841
BR, ADi

Smokedaddy
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Location: Phoenix, Arizona
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Post by Smokedaddy »

I actually have one of those but never used it. I thought it was an eyepiece reticle to (somehow) measure things directly through the eyepiece.

Image

-JW:

Smokedaddy
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Post by Smokedaddy »

Updated image to include a scale bar.

... not that it matters, here are a couple of pics I just did with it. Canon 50D, a Canon 1.4x teleconverter, a couple extension tubes and a Nikon Plan Apo CFN 10X/0.45.

Below, 100% crop;

Image

Below full size image, just resized to 1024;

Image

-JW:
Last edited by Smokedaddy on Tue Jan 30, 2018 12:39 pm, edited 3 times in total.

rjlittlefield
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Post by rjlittlefield »

Smokedaddy wrote:... not that it matters, here are a couple of pics I just did with it. Canon 50D, a Canon 1.4x teleconverter, a couple extension tubes and a Nikon Plan Apo CFN 10X/0.45.

Below, 100% crop;

Image
The roughness of these edges is quite worrisome. That'll probably make the automated analysis think that the edge has been smeared out over a larger width, artificially lowering the curve.

--Rik

Adalbert
Posts: 1062
Joined: Mon Nov 30, 2015 1:09 pm

Post by Adalbert »

Hello Rik,
This time the MTF of the single image from the stack:
Image


and of the DMap (cut 200x200 in the middle) :
Image

with the following threshold:
Image

BR, ADi

Adalbert
Posts: 1062
Joined: Mon Nov 30, 2015 1:09 pm

Post by Adalbert »

Hello Smokedaddy,
Would you please check if you can use this slide with the output-mode=profile of the MTF-mapper?
BR, ADi

Smokedaddy
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Post by Smokedaddy »

I am not familiar with the program, nor it's operations, settings and so forth. I did open a couple of images with the program but didn't adjust any settings. Here are the results. They both were 100% crops.

Update: I should of noted that the images I posted are just screen captures of the images I used and not the actual images.

Image

Image

Image

-JW:

Adalbert
Posts: 1062
Joined: Mon Nov 30, 2015 1:09 pm

Post by Adalbert »

Hi Smokedaddy,
Really nice curve :-)

BTW, I have ordered this one:
https://www.ebay.de/itm/Mikroskop-Testp ... SwTEJaDF7x

This is the test 2 but I have already shown the test 1 from the BW-Optik in the following thread:
http://www.photomacrography.net/forum/v ... highlight=

BR, ADi

billjanes1
Posts: 86
Joined: Fri Dec 30, 2016 1:59 pm
Location: Lake Forest, IL, USA

Post by billjanes1 »

rjlittlefield wrote:
lothman wrote: I'm actually pretty happy with the results that ADi is getting with his razor blade. Perhaps the razor blades that I have looked at in the past were just badly made. I'll get another sample next time I go to the grocery store.
--Rik
Rik,

You might consider looking at these German razor blades that Jim Kasson uses in his macro MTF testing. You might not find them in you local grocery store, but I had no trouble getting them online.

Regards,

Bill

http://blog.kasson.com/the-last-word/to ... -protocol/

rjlittlefield
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Post by rjlittlefield »

Actually I could not find any double-edge razor blades at several grocery stores, so I ordered a couple of different brands at Amazon.

On quick examination, one of them looks to have sections that may be usable even at high magnification.

Now I just need to find time to run some careful tests.

--Rik

Smokedaddy
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Post by Smokedaddy »

I do extreme paper cutting and never thought about using one of the Swann-Morton #11 surgical scalpel blades I use. I would think their edge would be the sharpest. I know they're sharper than the typical #11 X-Acto type blades.

Smokedaddy
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Post by Smokedaddy »

I was also just reading about polished feather blades. Seems they have the sharpest edges of any but I couldn't find a comparison between those and a scalpel blade.

rjlittlefield
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Post by rjlittlefield »

The edge must be not only sharp and smooth, it must also be perfectly straight. Several of the blades that I've looked at have edges that appear sharp and smooth, but when the stage is slid sideways, my eye picks up shallow scallops along the edge. I have not experimented with any of these, but I would not expect a scalloped edge to give accurate results.

--Rik

Smokedaddy
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Post by Smokedaddy »


Smokedaddy
Posts: 1696
Joined: Sat Oct 07, 2006 10:16 am
Location: Phoenix, Arizona
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Post by Smokedaddy »

I was reading on one of the knife/blade forums and razor blade forums about this. Seems the Feather razors were the sharpest. There's a guy that had access to a SEM that did a review on quite a few brands but the links seem to be broken. I did find the pics in another search.

As for the scalpel blades they're absolutely the sharpest without a doubt for my hobby, nothing compares. However I haven't a clue how they compare to razor blades.

http://s1200.photobucket.com/user/scalm ... t=3&page=1

http://photobucket.com/gallery/user/sca ... Zw==/?ref=

... and the forum where it all started;

https://www.badgerandblade.com/forum/th ... es.386550/

-JW:L

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