jcartwright

<p>Thanks for your responses, everyone. I suppose the answer is: no-one really knows what auto ISO does! I might contact Nikon to see if they can explain the behaviour – for although I can happily use the flash without auto-ISO, it would be reassuring to know why the camera selects the settings it does.</p> <p>If Nikon gives me a good answer, I'll post it here, of course.</p>

<p>Hi, I have just acquired an SB-400 external flash to pair with my D5100, and am encountering a problem when using it for fill-in flash.</p> <p>I normally use the camera in aperture-priority mode with ISO set to AUTO and the shutter set to a minimum of 1/60th. For fill-in, I usually like to compensate the flash minus 1 or 2 stops so that it is just taking some of the darkness out of the shadows, but not overpowering the ambient light. When using the camera's built-in flash this works fine: the image is exposed exactly the same as it would be with no flash; the flash simply "fills in" the shadows a bit. Great!</p> <p>However, when using the external SB-400 the compensation does not appear to work. Instead of the camera exposing correctly for ambient light and the flash filling-in the shadows by minus 1 or 2 stops (whatever I have set it to), the overall picture is underexposed by minus 1 or 2 stops. The problem seems to be related to the auto-ISO function, because when I set the ISO manually the compensation works again.</p> <p>As an example, I took a photo indoors with no flash at f/3.5. The shutter automatically selected 1/60th and the ISO automatically selected 1600. The exposure was correct.</p> <p>I did the same using the built-in flash. Whether I set it to zero compensation or -2 stops compensation, the camera exposed at 1/60th, ISO 1600. The exposure was correct.</p> <p>I did the same with the SB-400 external flash. I set it to zero compensation, and the camera exposed at 1/60th, ISO 500. The exposure was correct. (I presume lower ISO because the flash is more powerful.)</p> <p>Again using the SB400, I set it to -2 stops compensation, and the camera selected 1/60th, ISO 110. The picture was underexposed.</p> <p>As you can see, the flash compensation setting, when used in tandem with auto ISO, reduces the OVERALL exposure, not the fill-in exposure.</p> <p>Am I doing something wrong?</p> <p>I borrowed an SB-700 flash, and the same thing occurred, so it is not a fault with the flash. As I said before, if I turn off auto-ISO, the problem goes away: the flash compensation setting returns to adjusting flash compensation, not overall exposure.</p> <p>Any advice would be most welcome.</p> <p>Jon</p>

<p>Hi everyone, I was hoping you could give me some advice on what to expect in terms of photo book quality.</p> <p>Recently I ordered my first photo book from Blurb. I spent a lot of time soft-proofing the images in Lightroom 5, and in general I was pleased with the colour reproduction in the final book. However, I was not so pleased with the graininess of the photos, which to me looks like poor printer resolution.</p> <p>Here, for instance, is one of the original photos, taken with a modern Voigtlander 20mm lens on a Nikon D5100:</p> <p><img src="http://d6d2h4gfvy8t8.cloudfront.net/17654898-lg.jpg" alt="" width="600" height="400" /></p> <p>And here is a crop of one of the faces:</p> <p><img src="http://d6d2h4gfvy8t8.cloudfront.net/17654897-lg.jpg" alt="" width="600" height="600" /></p> <p>Now, it turns out I had already had this photo printed at 6"x4" by a professional photo lab (Peak Imaging UK). Here is a crop of a photo of that print:</p> <p><img src="http://d6d2h4gfvy8t8.cloudfront.net/17654899-lg.jpg" alt="" width="600" height="600" /></p> <p>Ignore the colour balance for now, and also ignore the reflections (it was a glossy print). Overall, I would say it is a good reproduction.</p> <p>But now take a look at how that very same photo was printed, at almost exactly the same size, in the Blurb photo book:</p> <p><img src="http://d6d2h4gfvy8t8.cloudfront.net/17654896-lg.jpg" alt="" width="600" height="600" /></p> <p>As you can see, the half-toning is clearly visible, and it is noticeably grainier. (Also it appears to be sharpened more, but that doesn't bother me so much.)</p> <p>My question is, ought I expect this from a photo book? Or should I be expecting similar print quality to standalone prints from a lab?</p> <p>I opted for Blurb because it seemed to get the best reviews, and because it was helpfully integrated in the Book module of Lightroom. I chose the best paper – I think it was called Proline Pearl Photo.</p> <p>What do you think? Am I being too pernickety?</p> <p>I have sent these photos to Blurb's customer support too, and am awaiting a response.</p> <p>Any advice would be gratefully received.</p>