ISO 100 on A500

[dianedh]

<p>Am I crazy?<br>

Last month I went out to California to see my brother and forgot my polarizer filter. I tried to set the ISO on my A500 to 100 but the lowest it went to was 200. I've checked the manual and can find nothing. <br>

Now, I'm certainly no expert (more an active novice), but there must be something I can do. Give me some ideas I can try when I'm out in really bright sunlight - or if there is a way to set the ISO to 100, tell me how to do it :)<br>

Appreicate it!</p>

[gregory_king1]

<p>Nope, most of the cameras only go to ISO 200...it's the native ISO setting. Some models go to 100, but it's somewhat "artificial"...it forces a one stop overexposure then push processes it down a stop, so you lose dynamic range.</p>

[phule]

<p>Diane,</p>

<p>What, at ISO 200, can't you do that you would be able to do at ISO 100? </p>

 

[parv]

Rob, one would not have to use a polarizer or a neutral density filter to reduce exposure by one stop without change in shutter speed & aperture. Or, was that a trick question from you? Also (*emphasis* is mine) ...

 

"Last month I went out to California to see my brother and *forgot my polarizer* filter. I tried to set the ISO on my A500 to 100 but the lowest it went to was 200." -- Diane H.

[phule]

<p>There is no "trick" question. I am asking about Diane's needs. A polarizing filter is not a ND filter and should not be used as one. If Diane's needs are large aperture, in bright light, then a ND would be a better solution if she is making out her shutter speed. If polarization is needed then a polarizing filter should be used. </p>

[dianedh]

<p>Thanks guys...<br>

I am still trying to convert my 'film' knowledge into digital. When I shot film outside on very bright days, I'd generally use ISO 64, or at the very least 100, set my X700 to Progam and get wonderful shots. <br>

Now I'm trying to shoot A priority. With a shot like this <a href="../photodb/photo?photo_id=15538864">http://photo.net/photodb/photo?photo_id=15538864</a> what can I do? This was shot at f11. </p>

[phule]

<p>[[With a shot like this <a href="../photodb/photo?photo_id=15538864" rel="nofollow">http://photo.net/photodb/photo?photo_id=15538864</a> what can I do? ]]<br>

Diane,</p>

<p>What is it that you want to do? Do you need a slower shutter speed and don't want to shoot at a smaller aperture? Are you concerned about shooting at f/11? </p>

<p>ISO 200 on a modern digital SLR is very clean. It's not equivalent to ISO 200 film in terms of performance. So, unless you have a specific need like, shooting at f/1.8 in mid-day sun and your camera doesn't offer a max shutter speed of 1/8000, I would not be too concerned about ISO 200 being the lowest available. </p>

<p>For that shot in particular, the deep shadows are a result of shooting in the available light. Your shot would not have been any different at ISO 64. With digital you can, in post, fill in the shadows (at the expense of noise), but not a lot else could have done in a single shot. A polarizing filter would have helped darken the sky but you still would have needed to increase exposure compensation in order to fill in the shadows. Again, being at ISO 200 vs any other ISO would not have made any real difference.</p>

 

[phule]

<p>In the review of the Sony A550, which was released at the same time as your A500, dpreview noted the following:</p>

 

<blockquote>

<p>As you can see in the first example below the very brightest clipped areas (the highlight on the metal in the middle right of the crop) aren't recovered, and exhibit the usual color shifts / posterization, but everything else - including areas that appeared to be clipped - have plenty of tonal information hidden away that's easily recovered using negative exposure compensation at the raw stage. This is important, as the A550's metering is far from reliable, often overexposing outdoor scenes by at least a stop. Interestingly you'll also get fractionally less noisy ISO 200 images if you intentionally over-expose and pull it back in raw mode (the sample at the bottom of this page has none of the mild noise often visible in blue skies in correctly exposed ISO 200 raw shots.<br>

http://www.dpreview.com/reviews/sonyalphadslra550/15</p>

</blockquote>

<p>That is to say, if you exposed more for the shadows, and were shooting RAW, you can pull back the exposure on the highlights with a single image and end up with something (probably) you're looking for. Now, the A550 may behave differently than the A500 as it has a different sensor, but it certainly would be worth a shot (after all, it's digital, so the cost to experiment is only your time.).</p>

[dianedh]

<p>Rob,<br>

Thanks for the info - and for the questions about what I really want to know! I guess I'm not really sure. (Sure doesn't make answers any easier :) )<br>

I just know that I'm not satisfied with the results I'm getting but don't really want to resort to Program mode. I keep remembering the deep, rich colors I got with the Fuji 64 slide film. <br>

In the case of the shot I linked to earlier, what difference would it have made if I'd shot it at f22? Enough to be visible?</p>

 

[john_tran14]

<blockquote>

<p>When I shot film outside on very bright days, I'd generally use ISO ??, or at the very least ???, set my X700 to Progam and get wonderful shots</p>

</blockquote>

<p>You would get such wonderful shots by setting your A500 to Program</p>

 

<blockquote>

<p>Now I'm trying to shoot A priority. With a shot like this ... what can I do? This was shot at f11.</p>

</blockquote>

<p>You do exactly the same: shoot A priority, at f11</p>

<p> </p>

[phule]

<p>[[i just know that I'm not satisfied with the results I'm getting but don't really want to resort to Program mode. I keep remembering the deep, rich colors I got with the Fuji 64 slide film. ]]<br>

<br /><br>

You are in control of how your camera renders images by way of the Fn --> Creative Styles menu. If you're not interested, or don't have a need, to shoot RAW files right now, you have the ability to adjust the contrast, the saturation, the sharpness, the white balance, and other such elements in your camera. Don't take the default settings, make the settings your own.</p>

[dianedh]

<p>Rob,<br>

I haven't really gotten into making adjustments in the camera -- I'm still trying to get used to the new digital technology (vs my old X700). I KNOW there is an Fn button but haven't touched it since I first got the camera.<br>

I guess I just need to shoot more so I can get more familiar with. and learn, more ofl of various functions of the camera. <br>

I do appreciate your time and suggestions. </p>

[randy_cooprider1]

Diane, I didn't see this until today so you may not get this response. I looked at the seal rock picture and liked it a bunch. What I noticed was that the foreground was sharp and the distant objects were soft. Did you try picking a focus point further away and then recomposing? The F11 setting on the digital camera is equivalent to a higher F# on film cameras because of the optical difference in the design. Using F22 will probably cause loss of sharpness due to diffraction effects. The depth of field at F11 should allow both near and far objects to be sharp. The more intense color that you want can be pumped in by using an editing program. Don't know what you are specifically looking for but attached is a trial run.

 

Cheers,

 

Randyc

[randy_cooprider1]

Attachment

[randy_cooprider1]

A jpg works better.<div></div>

[dianedh]

<p>Randy,<br>

MANY thanks! I didn't know that the f# was affected by digital. I knew my crop sensor altered my lens but not about the f#. That will certainly be another thing to remember as I keep working on translating my film knowledge to digital.<br>

Your color adjustments are more what I was hoping for.<br>

I generally shot Fuji slide film and sent it to Fuji for processing. The colors were always so vibrant. Guess I'm just looking for the best possible shot, right out of the camera. I want to take better pictures, not make them better in post processing.</p>

[phule]

<p>Your crop sensor in no way "alters" your lens. Your lens has physical properties that do not change (unless you "change" them by running it over with a steam roller). </p>

<p>You can safely ignore the "diffraction" issue unless you're making 20x30 prints. Far too many people focus on diffraction as if it is the boogieman. Subject matter, composition, etc., trump any such subtle changes that diffraction might introduce. </p>

<p>Concentrate on learning how to operate your camera, that will get you the most benefit. </p>

[dianedh]

<p>Rob,<br>

Guess what I should have said was that on my crop sensor, my 18MM is more like a 24mm(?) I'm not sure of the math but I know it's not as wide as the full 18. But then it also gives me a longer telephoto on the 200mm end.</p>

<p>There is just so much to learn about these digitals!</p>

 

[randy_cooprider1]

Rob,

 

You are correct, the "crop" sensor does not alter the lens however it does alter the portion of the lens that is used and where the sensor is spaced from the back of the lens. Since the sensor is smaller than a 24x36mm 35mm film negative, the digital frame produces an apparent magnification. This has been discussed in many postings. So a 50mm Sony lens is about 80mm on my A100. Along with this is an increase in depth of field because the sensor is closer to the lens. The depth of field at F16 on a APS C sized sensor is approximately F22 on a 35mm film camera. You may have noticed that several 50mm standard lenses on film cameras have F16 as their smallest aperture. I have seen diffraction effects on 8x10 prints at F22. I agree that the picture characteristics you describe are more important than diffraction unsharpness but why not go for the best?

[gregory_king1]

<p>Randy,<br>

Almost correct. The sensor is in exactly the same spot. Moving it would destroy the ability to focus properly.<br>

The reason your DOF changes is because you have to back up to frame the same image with the crop camera. Since DOF is a function of focus distance, it goes up.<br>

Take the same image from the same spot with the same lens at the same aperture on two cameras (crop and FF) and you'll get the same image with the same DOF. One is just cropped.</p>

[randy_cooprider1]

Gregory, thanks for the correction. I have experienced it, but didn't have the reason right.

[phule]

<p>[[i agree that the picture characteristics you describe are more important than diffraction unsharpness but why not go for the best?]]</p>

<p>Because it is a needless distraction. For many photographers, any effects from diffraction are going to be swallowed up by much larger errors in image capture.</p>

<p>[[ I have seen diffraction effects on 8x10 prints at F22]]</p>

<p>I don't look at my 8x10 prints from 1/2 inch away, perhaps you do, that's your choice. I will, however, place good money on you not being able to discern a f/16 8x10 from an f/22 8x10 at a normal viewing distance.</p>

<p>[[You may have noticed that several 50mm standard lenses on film cameras have F16 as their smallest aperture.]]</p>

<p>This has nothing to do with diffraction. This is a function of lens design. I have multiple zoom lenses, and at least one prime, that go to F/32. While the prime is a full-frame lens, the zooms are designed for an APS-C sized sensor.</p>

[randy_cooprider1]

...I don't look at my 8x10 prints from 1/2 inch away...

 

Neither do I, in fact 1/2 foot is pretty much out of the question without a magnifier.

 

If a search of PN is done by entering the word "diffraction" in the box, a lot of information can be accessed. I was doing this and opened a page where the results of different apertures on picture qualities was shown. They first cropped the picture then compared the quality.

 

If the entire negative/sensor is used then diffraction effects will probably be negligible.

 

However, since I often crop, the sharpness loss of light diffracting from the shutter is definitely active as shown on the PN discussion.