DX vs. 1.3 crop mode on D7100: This is confusing to me. I understand that I get more FPS in 1.3 crop mode. Other than that, what, if any, are the advantages of shooting in 1.3 crop...

Pine1 Loc: Midland & Lakeway

This is confusing to me. I understand that I get more FPS in 1.3 crop mode. Other than that, what, if any, are the advantages of shooting in 1.3 crop mode? I ran a search and didn't find anything.

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

I think the crop mode is not what it's cracked up to be... You are better off cropping in post as trying to stay within the frame lines in the viewfinder is a pain.

jeep_daddy Loc: Prescott AZ

It confuses me too. Since the D7100 is already a 1.5 crop sensor body how can it produce a 1.3 crop image or be in a 1.3 crop mode in the first place. The only thing I can figure is that the 1.3 crop mode means that the amount of the already smaller DX sensor is cropped even further to produce a more cropped and smaller image allowing the camera to shoot a little faster since the files sizes are smaller than when using the whole sensor.

jchristian Loc: Baker, OR

I have a 7100 but have never used the crop feature except to try it. I know I'm no help but just have never needed it. I'll be interested to see what others say. Jim

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

When using the 1.3x crop mode, it reduces the sensor size to the same size as Olympus sensors (same as my Olympus Pen E-P3)

GoofyNewfie Loc: Kansas City

Screamin Scott wrote:

When using the 1.3x crop mode, it reduces the sensor size to the same size as Olympus sensors (same as my Olympus Pen E-P3)

So it would be the same as using a micro 4/3 sensor?
Interesting.

steve_stoneblossom Loc: Rhode Island, USA

Shooting speed is an obvious advantage.

Auto focus coverage would be one more. Focus points cover the majority of the 1.3x crop area.

amehta Loc: Boston

Pine1 wrote:

This is confusing to me. I understand that I get more FPS in 1.3 crop mode. Other than that, what, if any, are the advantages of shooting in 1.3 crop mode? I ran a search and didn't find anything.

The 1.3 crop mode gets multiplied with the DX crop factor of 1.5 to give an effective crop factor of 2x compared to full frame.

Just like using DX-mode on the FX bodies, this is only useful to increase speed because of the smaller file sizes.

amehta Loc: Boston

GoofyNewfie wrote:

Screamin Scott wrote:

When using the 1.3x crop mode, it reduces the sensor size to the same size as Olympus sensors (same as my Olympus Pen E-P3)

So it would be the same as using a micro 4/3 sensor?
Interesting.

Close, but not exactly. The 1.3x mode on the D7100 still has a 3:2 aspect ratio (18x12mm), while the m4/3 has a 4:3 aspect ratio (17x13mm).

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

You are correct there...

amehta wrote:

Close, but not exactly. The 1.3x mode on the D7100 still has a 3:2 aspect ratio (18x12mm), while the m4/3 has a 4:3 aspect ratio (17x13mm).

GoofyNewfie Loc: Kansas City

amehta wrote:

Close, but not exactly. The 1.3x mode on the D7100 still has a 3:2 aspect ratio (18x12mm), while the m4/3 has a 4:3 aspect ratio (17x13mm).

Got it! Thanks.

Pine1 Loc: Midland & Lakeway

Thank all of you for your responses.

Brucej67 Loc: Cary, NC

If using a full frame lens on a crop frame camera (namely the D7100) you get a crop factor of 1.5 times what is stated on the lens, in other words a 100mm full frame lens has an equivalent of a 150mm in image area. Using the least example if shooting in 1.3 crop mode you now have the times factor of 1.8 which on the previous example is an equivalent of a 180mm in image area. Some people use this as extending the lens without having to use a tele extender which would degrade aperture setting.

Pine1 wrote:

This is confusing to me. I understand that I get more FPS in 1.3 crop mode. Other than that, what, if any, are the advantages of shooting in 1.3 crop mode? I ran a search and didn't find anything.

amehta Loc: Boston

Brucej67 wrote:

If using a full frame lens on a crop frame camera (namely the D7100) you get a crop factor of 1.5 times what is stated on the lens, in other words a 100mm full frame lens has an equivalent of a 150mm in image area. Using the least example if shooting in 1.3 crop mode you now have the times factor of 1.8 which on the previous example is an equivalent of a 180mm in image area. Some people use this as extending the lens without having to use a tele extender which would degrade aperture setting.

How did you get 1.8x?

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Crop factor is not a function of whether you use an FX or DX lens. A 100mm DX lens will still provide the same angle of view of a 150mm lens on a FX camera. But it will still have the same depth of field as a 100mm lens at similar image magnification. This means that on the DX camera, you would have to move further away for the same image size/angle of view of a 150 on an FX, which increases your dof.

If you need the frame rate shoot 1.3, but you will have even more DOF and you will have fewer pixels. You are probably better off cropping the full image in post processing. Besides with the faster frame rate sometimes a fast moving subject will be out of focus, since the AF performance will have trouble keeping up. I get that all the time with a D700 using a battery grip, which shoots 8fps, and I see it less with my D800 which has a max 4 fps, and a better AF system.