Alpha 300 Manual

[Brandi Wendelberger]

Butif my "blend" layer (the top image) has transparency in it, I'm a little flummoxed as to how to factor that alpha into the blending equation correctly. I expect it to work such that transparent pixels in the blend layer have no effect on the result, opaque pixels in the blend layer do the overlay blend as normal, and semitransparent blend layer pixels have some scaled effect on the result.

Bonus points if you can help me do it such that the resulting image has correctly premultiplied alpha (which only comes into play for pixels that are not opaque in both layers, I think.)

This works great, using formula from here: My function is a bit funky because it takes in a DoubleColor which is 0-1, and a T* pixel color which is 0-maxValDouble() (which is the max val of the integer type being used, as a double).

Regardless of which mode I set the camera to ( A, P, S, etc.) and regardless of which Sony lens is on the camera I can't get the focus mode option in my menu area to allow me access. It is stuck in manual. When I select it I get a message my lens isn't supported or is improperly attached (neither of which is true). This a new problem and I know it probably has a simple solution but I am stuck. What am I doing wrong? Any suggestions?

Thank you adwb for responding. The focus lever was where I started, but unfortunately no joy found there. Also tried rebooting to the original settings- no joy there either. Just spent an hour with a Sony technical rep- the upshot being the camera is being sent back to them. Apparently there is some flaw in the circuitry. Again thanks for trying.

Since I already had a older a6000 i tested my 85 mm on that and it worked perfectly fine. And thats where i realized that the answer to it is very simple and that is your lense attachment to the body. It gives a little click sound when the lense is locked to the body properly which i wasnt able to achieve and was leaving the lense attached half way through as i was being way too careful with brand new gadgets. The click is easy on a6k, however with the brand new a7iii body and 85mm lense i had to twist a little bit harder to get that click and boom the problem was solved. The manual focus mode was no longer grayed out!

Disconnect lens, adaptor, and body (keep it safe from dust though). Attach lens to adaptor. Before putting lens+adaptor combo on body, make sure camera is off, and hold the circle button on the adaptor while attaching to camera body. This boots up some kind of advanced mode. I'm using a metabones V and the light that's usually blue goes red, and then autofocus is enabled.

Problem is it seems there are only two choices: Manual OR Autofocus buttons on the lens., With some of my old lenses (Nikon), if I had it in autofocus, and then turned the manual dial I could jump to manual.

With this lens, with the selector switch set to Autofocus, if I want to change to Manual, it seems I have to take my eye away form the viewfinder, search for the Manual button and click that on. Is there no override on this lens?

And reading what you sent me got me to understand a lot more about focusing using this lens. Specifically about 'MF Assist (still image)' which was driving me crazy, but now I know how to turn it on or off!

I had this question too. It's very strange for sony not to hava any kind of manual override focusing. I was so used to use it on my Pentax system. Fortunately, Sony has a very good AF, but it would still be useful in cases where automatic AF struggles.

Regarding DMF mode? Sure, but it requires an extra action. Manual focus override is, in my opinion, useful in cases when you are in AF-C and an animal sneaks behind some branches or any other situation where you need to be quick.

NOTE: this was only on a handful of lenses UNTIL the A7RV, which supports Full-Time DMF on most lenses - so on the A7RV you enable it in the body, and most lenses allow the focus ring to override AF.

How do you adjust the aperture in manual mode, my dial works with shutter speed. I mean i can if I goto aperture priority then back to manual but there had to be an easier way am I missing something simple?

7:28PM, 27 December 2010 PDT(permalink)

It is really one of the important differences between the A77 and the A65, A55 and A35. The twin dials does make a difference. Especially since the second dial can be programmed to do exposure compensation in P, A or S-mode ... that is REALLY useful!

ages ago(permalink)

Porcine pancreatic alpha-amylase (PPA) acts upon large linear carbohydrate polymers at internal bonds. The hydrolytic products have alpha-configuration. alpha-Amylase activity is present in all living organisms; however, the enzymes vary remarkably even from tissue to tissue within a single species.

The alpha-amylases were named by Kuhn in 1925, because the hydrolysis products are in the alpha configuration. In 1930, Ohlsson discovered another amylase, which yielded a beta-mannose. He named it beta-amylase. In 1947, the enzyme was first crystallized from pig pancreas by Meyer et al., and Danielsson determined its molecular weight. In 1952, Caldwell et al. reported on an improved purification method.

Inhibitors of alpha-amylase were reported on as early as 1975 (Marshall and Lauda 1975). The first crystal structure of alpha-amylase was from Aspergillus oryzae and was determined in 1979 (Matsuura et al. 1979). This 6 resolution structure was improved to a 3 resolution the following year (Matsuura et al. 1980).

In the 1980s, the amino acid sequences of the two forms (PPAI and PPAII) were determined (Kluh et al. 1981, and Pasero et al. 1986). The three dimensional crystal structures of each form were determined in the 1990s and found to be effectively identical (Qian et al. 1993, and Gilles et al. 1996). The complete cDNA sequence was determined by Darnis et al. in 1999.

Recent work with alpha-amylase has included isolating and studying the effects of inhibitors from natural sources (Narita and Inouye 2009, and Suda et al. 2011). Researchers have also studied the effects of bound carbohydrates on enzyme stability (Gopal et al. 2008) and analyzed the binding of inhibitors with the aim of designing novel inhibitors (Najafian et al. 2011).

alpha-Amylase catalyzes the hydrolysis of internal alpha-1,4-glucan links in polysaccharides containing 3 or more alpha-1,4-linked D-glucose units, yielding a mixture of maltose and glucose. See also Takeshita and Hehre (1975).

Animal alpha-amylases contain five conserved regions including four at or around the (alpha/beta)8-barrel and a short sequence near the C-terminus of domain B (Janecek 1993, Svensson 1994, and Janecek and Balaz 1995). Human and porcine pancreatic alpha-amylases are 87.1% identical, with only 64 amino acid substitutions. Mouse and rat alpha-amylase share a 85.5% identity with that of porcine. Amino acids 304-310 are conserved among mammalian alpha-amylases and are believed to be involved in the enzymatic mechanism (Darnis et al. 1999).

Tip 1: I can only recommend to assign the focus magnifier function to an easily accessible button. The default position is C1 but I find that button hard to reach. My choice is the AF/MF button.

Go to menu/ gear wheel/ 6 or 7 /Custom Key Settings/ AF/MF Button and select Focus Magnifier.

Tip 3: Top improve precision with focus peaking first try to get focus about right. Then focus a little back and forth and observe how the peaking color wanders. This will give you a better feel for the optimal focus position but it also slows operation down so you could use focus magnification right away.

If you want to focus fast and precise you can take advantage of a technical shortcoming of the electronic viewfinder (EVF). The camera does not use all the sensor information to generate the live-view image but it skips lines which results in the moir-effect which we can use to our advantage.

You can learn to use it like this: The sharper your lens, the easier it is to see. Any 1.4/50 at f/2 should make it easy to see. Pick a subject with fine structures with some contrast like print or a carpet. Hold your camera steady and slowly focus. Now you should see sharp parts of the image to flicker. Once you know what to look for it is easy to see with softer lenses and

I also find that for landscapes and nature images my results are more reliable than when I use AF and I enjoy the process more because it is me who is focusing, not the camera guessing were I want to focus.

Of course there are many situations were AF is superior. If you have a young child a a7III with a 2.8/24-70 is a much more handy tool than a manual focus prime. With some experience you should be able to capture friends and family with manual lenses.

If you want to explore manual lenses I would recommend you to start with a normal lens. Normal lenses can be used for a wide range of applications so when I decided to limit myself to only one lens for a whole month I decided to use a Minolta MC 1.7/55. Here is my selection of a three very different normal lenses you should consider to get started with manual lenses.

I like to recommend the Minolta 1.7/55 as first manual lens so well balanced and for me it stands for all the good qualities of legacy lenses. It is small yet very solid. It comes with a few optical compromises but these usually do not really affect the quality of your images. And last but not least it is dirt cheap at $20-30.

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