Photography Q&A

Tuesday, May 1, 2012

Why do I get two JPEG files instead of RAW+JPEG when transfering to my computer from my Nikon D5100?

Question

I have a Nikon D5100 and I want to shoot RAW and JPG at the same time. I select RAW+N (RAW plus Normal Size JPG). Now when I export the shots to my computer I end up with two files called DSC_0123 (1).jpg and DSC_0123.jpg. (Both files are the same size). I am missing the raw NEF file. Why is the camera doing this and is something set wrong?

Note: When shooting in RAW only the files are produced normally and function as expected. The firmware is the latest Version (1.01). I have 3 modes for RAW + JPG -- They are RAW+B (Basic) RAW+N (Normal) RAW+F (fine) all three produce JPG and no raw file.

Here are a few ideas that I have tried:

Reset Camera Settings
Try another memory card (Note: The memory cards I have are all Transcend 16GB Class 10)

Asked by Lynda

Answer

From reading http://forums.dpreview.com/forums/readflat.asp?forum=1034&message=38261447&changemode=1

and

http://forums.dpreview.com/forums/readflat.asp?forum=1034&message=21930545&changemode=1

You will need to have Nikon's Transfer software or use View NX 2

UPDATE: As a side tip (maybe you already do this) but I never connect my DSLR to the PC I always use one of these - Bottom line is - I dont want something to go wrong with my camera on the PC - I would much rather a memory card take that hit.

Answered by Rob

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What is ETTR (Expose To The Right)?

Question

Picking up from this answer and this question, What exactly is ETTR? How it may reduce the image noise? And how is it difference from film to digital sensors?

In the answer linked above, what are the 5 stops and is it related to ETTR?

In real life how can I apply this technique when I'm shooting?

Asked by Akram Mellice

Answer

"Expose to the right" means record the brightest image you can and then reduce the brightness in post to achieve the desired level.

The word "right" comes from the histogram, where conventionally brightness increases left to right, thus increasing brightness shifts the whole histogram to the right.

ETTR helps reduce noise simply by capturing more light, which reduces photon noise, and gives a better signal to [electrical] noise ratio (by virtue of a bigger signal). The reason high ISO photos look noisy is due to low levels of light and amplifying a weak signal.

The technique works provided you don't increase the exposure to the point where it hits the maximum possible value and gets cut off, as this will result in a loss of information (known as clipping/blowing the highlights). Typically this is seen as an area of the image (usually sky) which has gone pure white.

In principle the technique works for film, certainly exposing the left and then having to push your image when printing will increase grain. However film has a different cutoff characteristic, as highlights gently roll off rather than hitting a hard limit.

Here's an experiment I did to demonstrate the effect (and rebuff a blog article which claimed ETTR didn't work):

Here's the camera metered exposure:

Here I've used ETTR and increased the camera meter's exposure by 1 stop using a longer exposure:

Finally, to show the difference here's the standard exposure with the ETTR image offset in the centre:

The reduction in noise is visible, particularly in the purple patch in the bottom right.

Answered by Matt Grum

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Tips for capturing fast-moving subjects in low light

Question

I will be attending a rally driving event but the weather forecast is for rain and cloud. How can I ensure I stand a good chance of getting some good action shots under these conditions? I have a Nikon D3100 with 18-55mm kit lens, 55-300mm telephoto and the 35mm 1.8 prime lens.

My intial thoughts were to use the long telephoto lens in shutter-priority mode and let the camera choose the aperture/ISO, but with limited aperture at max zoom, I'm concerned about noise/grain in the images. I have an SB-400 flash - will this make a difference?

The prime lens will obviously let in more light, meaning I can keep the ISO lower, but I won't be able to get close to the subject so may have to crop the images heavily.

Any other suggestions or tips?

Asked by Jazza

Answer

Unfortunately, both your zoom lenses are quite slow. By contrast, a mate of mine uses a 400 f/4 or 200 f/2 for his action photography. You are right about the prime lens. It would perform much better, but of course you would need to crop later. If you're up-close however, it may be an option.

With your current setup, I'd say to use the speed priority as you mentioned. Depending how close you are to the action and relative speed of the cars, use a shutter speed of around 1/320th if they are quite far, or 1/800th-1/1600th if you are close up. Use auto-ISO and let the camera choose the aperture and ISO.

In open conditions like this, a flash will be no good to you whatsoever, as the flash range just won't be enough. This will be compounded by the camera being 'tricked' into thinking whatever it is taking a photo of will be lit up by the flash and will result in even more under-exposure.

Make sure you shoot in RAW (this is the only reason I don't suggest the built in 'sports' mode - I think that will only capture in JPG?). RAW means that in post, you'll have better chances of suppressing any noise and balancing grain with sharpening.

Also make sure you use continuous servo AF. I think the D3100 also has some kind of 'predictive' AF - so read up in your manual on using that. But the continuous AF will ensure it keeps the car in focus as you're panning, so helping get a better photo.

Finally, use spot metering so your camera knows to expose only for the subject under your AF point. This will help ensure you get the right exposure for the car - not the overall gloominess of the skies!

Good luck!

Answered by Mike

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Nikon D5100 - Saving RAW and JPG Files

Question

Here are a few ideas that I have tried:

Reset Camera Settings
Try another memory card (Note: The memory cards I have are all Transcend 16GB Class 10)

Asked by Lynda

Answer

From reading http://forums.dpreview.com/forums/readflat.asp?forum=1034&message=38261447&changemode=1

and

http://forums.dpreview.com/forums/readflat.asp?forum=1034&message=21930545&changemode=1

You will need to have Nikon's Transfer software or use View NX 2

Answered by Rob

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What is the best method to digitize and touch up my old slides?

Question

I have lots of old slides and should probably digitize them? What is the best way of achieving this? What kind of touchups might be necessary?

Asked by txwikinger

Answer

If you would like to scan the slides the "Epson Perfection V500 Photo Scanner" seems to get good reviews for slide scanning as well for scanning 35 mm negatives - see amazon (4 stars and 281 customer reviews): http://www.amazon.com/dp/B000VG4AY0/

If you would like to outsource it - ScanCafe might be a good option: http://www.scancafe.com/

Answered by Imageree

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What is the technical difference between focus and zooming?

Question

This may look like a silly question but I don't know what the difference between zooming and focusing is. Zooming in will usually let me have fewer subjects in the scene while zooming out will allow for wider view. Focusing is the process adjusting the wanted subject to be in focus and look sharp. When we zoom, lens elements are moved to zoom in or out, what happens in the lens when we change the focus?

Asked by Akram Mellice

Answer

The two generally control two different aspects of the image projected by the lens. Focusing sometimes has the effect of changing "zoom" a little as well, however its purpose is different. To keep it simple:

Focus adjusts the Focal Plane
- The focal plane is the thin plane of reality that is focused clearly on the imaging medium
- Focusing moves this plane nearer or farther from the camera's sensor/film
Zoom adjusts the Angle of View
- The angle of view is the breadth of the scene projected by the lens
- Wide-angle lenses tend to capture very broad scenes (large angle of view)
- Telephoto lenses tend to capture very narrow scenes (small angle of view)

Focusing in the past used to be achieved by moving the lens itself (i.e. in a large-format view camera) forward or backward (away/towards the imaging medium). This often results in changes to the angle of view as well, since the total focal length of the lens can change via extension...sometimes by a lot. In modern camera lenses, focusing may be achieved similarly...many cheap lenses focus by moving the front or back (or both) lens elements. Higher quality lenses tend to use an internal floating focus group, an internal group of lens elements who's sole purpose is to focus the image. The benefit of internal focusing groups is that the physical length of the lens stays the same, allowing you to minimize the amount of "zoom shift" that might occur when focusing.

Answered by jrista

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Should I really lug around a lens cap everywhere?

Question

I lose lens caps by the billion. Is there another way to protect my lenses without having to carry these things around with me?

Asked by brian

Answer

I keep a UV filter on most of the time as a secondary barrier - but to be honest, I just have to get into the habit of putting my lens cap in the same pocket each time I remove it. I've spent way too much time hunting around for the the damn things too.

Answered by dswan

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