Friday, February 9, 2018

If I have a film lens (designed for 35mm film cameras) what happens when I fit it to a cropped sensor digital camera

Long title to this post but this is generically one of the common questions ask when people from a stills film background or full frame digital camera background consider moving to Micro Four Thirds cameras. Curiously, they don't ask this question when they move from full frame to the smaller in-family APS-C camera? Why not, I ask, APS-C is still cropped.

Pose the question into a forum, wait a few minutes and all hell breaks loose. Those who are trolls smile gleefully, buy some popcorn and take a comfortable chair to watch the to and fro.

Words like "equivalent" are bandied about. Another one is "bokeh" often referring not to the original definition of the term - the creaminess of the background when it is blurred to the same extent but rather to the common interpretation - how blur is the background. Then people talk about the Crop being 2x but the sensor area difference being one quarter and the depth of field difference being two stops and the high ISO noise level being less than 2 stops, all things being equal. People go hunting red herrings from erstwhile, apparently sincerely presented text and now Youtube videos. Long held grudges (against the faceless camera manufacturers) burp up and tempers flare. If the tone of the discussion is strongly held calm, some sense may come out of it. Pity the poor newbie in the discussion thread or the visual, math allergic individual.

What happens is that people interpret different questions and of course, come up with different answers because the questions are different. And then people associate implications to the facts so vigorously that after a while, one cannot distinguish between an implication and a fact.  Here's my FAQ.

Q1. Do I dial in a different ISO / shutter speed / f/no with the same lens on different sized sensors?
Ans: No, You use the same parameters

Q2. Do I see a different image "quality" if I use the same lens on different sized sensors of the same technological edge / age?
Ans: It varies depending on some factors but in overall yes, the final image viewed at the same final size will show that the full frame image will have less noise. It may not be exactly proptional to the sensor size ratios

Q3. Will the amount of blur background be different when you use the same lens on different sized sensors for the same subject size in the frame.
Ans. Yes, there will be different background blur. A simplified but effective interactive web app that you can play around with is https://dofsimulator.net/en/

Q4. Will the inherent creaminess of a bokeh ball in the centre of the frame be different between the two bodies with different sized sensors?
Ans. Likely the bokeh ball will be the same character of wiryness, onion skin, or bokeh ball shape.

Q5. Will the whole frame blur and bokeh effect be different between the two different sensor sizes with the same lens?
Ans. Yes, the full frame style of picture will be different because the smaller sensor does not show you the blurry bits and vignetting of the lens that is around the rim/edge of the frame

Q6. Will the lens, say, 50mm, become 100mm when I fit a full frame lens on an Micro Four Thirds body?
Ans. No the lens will always be 50mm. However, because the MFT sensor is smaller than than a full frame sensor, the projected image will overspill the small sensor, so you will only see half the image (by height) standing at the same camera to subject distance. It will be like you are using a 100mm full frame lens on a 100mm full frame body. 

Have you learnt something from this?

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Monday, February 5, 2018

Getting frustrated with how the Microsoft Word keyboard cursor?

Microsoft Word has progressively been modified over time to make text editing easier for people. Unfortunately, every so often what the Word developers think is a good feature doesn't quite jive with the end users. One case in point is when you start selecting part of a paragraph and the keyboard cursor jumps to include the invisible paragraph mark or worse, the whole paragraph. Do you want to turn it off?

See Smart Paragraph Selection and Smart Cursoring

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Get VBA out of maintenance mode

Microsoft planned and delivered the .NET framework in 2000 and VB.NET in 2002. It's 2018, and that's a long time ago. .NET is now the main framework that Microsoft uses for the cloud apps and even for desktop.

Poor old Visual Basic for Applications (VBA), the "internal" and bundled programming language for Microsoft Office - Access, Word, Excel, Powerpoint, Project, Visio etc... was put on maintenance status - it would be updated to cater for operating system changes here and there but it has no new enhancements. Yet, VBA for Microsoft Office desktop has not died and passed on - as long as Microsoft Office desktop lives and runs, VBA will provide a programming facility to people.

VB.NET (or offshoot) shows no signs of replacing VBA Classic. And the two platforms do not compete in the same arena at all, they are complementary instead of being antagonistic. Why not enhance VBA. With features like Linq , String Interpolation, constructs to manage large chunks of text and so on.

Tell Microsoft you want it this way

Tuesday, December 5, 2017

Linked Transpose Formula

I've known about the static
Copy
Paste > Special > Transpose
forever.

Today, a class participant wanted a transpose but not static, she wanted dynamically linked formula.

Seems the =TRANSPOSE() function has been there for a long time. It's a CSE array function - so, select a range of blank cells in the shape of a transposed destination, use the expression {=TRANSPOSE(A1:B4)}

Remember you don't type the { } - they are bookended when you press Ctrl+Shift+Enter instead of Enter

See the TRANSPOSE() description

Thursday, September 1, 2016

Fonts and things in Microsoft Access

Microsoft Access designer tools have mostly been dormant and not improved over the years.

Query - SQL View font

Two things are cruel in SQL View. 

The SQL Text will not stay formatted and will automatically be wrapped - probably this is due to the two way interface between Query Design View and SQL View.

The font in SQL View isn't the best choice. You can change the font in SQL View but this also changes the Query Design View font.

File > Options > Object Designers > Query Design - Query design font

Expression Builder font

Put your cursor in the editable content text area of the Expression Builder. Ctrl+Mouse Scroll Wheel. Tip from Utter Access Forums

Tuesday, March 1, 2016

Insert Textbox - in Excel 2011 for the Mac

I don't have a Mac. The day will come (maybe) but in 30 years of working with Personal Computers, the only Apple I used was the Apple ][.

So once in a while, I encounter participants that bring a Mac along and the menus look different or items have different menu positions.

Today we couldn't find Insert > Textbox easily. Microsoft assures me it's there.

Also because I am so used to Windows's Right Click, that's Control + Click on the Mac.

Sunday, November 22, 2015

Registering VBEBookmarks.dll on 64 bit Windows 10 and Microsoft Office 2013

I've been using VBE Bookmarks for a long time. The VBA IDE that comes inside every Microsoft Office program (Word, Excel, Powerpoint, Access, Visio, Project) was the zenith of useability and productivity during the Visual Basic VB 6 days. And even in 2015, the year I am writing this, it is in Microsoft Office 2016. However, jumping around your code is tough because the native bookmarks are not numbered or fun.

Ron de Bruin hosts two 32 bit .dlls authored by Jim Rech (Excel MVP) - one of them is VBE Bookmarks. The thing you have to do is to download the .dll and register it (a.k.a. install it) on your machine. Before Windows 10 64 bit, I did not have difficulty doing that. But I did this time, I did. So with help from friends +Paul Pavlinovich +Greg Kerr and a Stack Overflow discussion thread, I managed to make it work.

1. To register a .dll, ensure the .dll has no dependencies on other .dlls which may be missing. In this case, vbebookmarks.dll relies on msaddndr.dll which may or may not be already registered.

2. Ensure that the .dll you want to register is in a folder where there is no uncertainty about access rights. I gave up and copied it to the %systemroot%\syswow64 folder.

3. For 64 bit .dlls use regsvr32.exe in %systemroot%\system32, for 32 bit .dlls use regsvr32 in %systemroot\sysWoW64.

4. Use an elevated command prompt by running cmd.exe as Admin.

Tuesday, September 29, 2015

Happy 30th Birthday Excel

Thanks to +Debra Dalgleish for alerting me to the date tomorrow - September 30. On that day in 1985, Excel (for the Mac) was released. That's 30 years ago. I hunted around for some old Excel and found Excel 2 for Windows (the first version for Windows). It comes with its own Windows runtime environment since Windows at that time was not commonplace. I managed to make it survive long enough to type in =NOW() - it's running in Oracle Virtualbox and the platform might not be 100% emulating well.