Using a graduated ND FIlter

Nice pic!! That mountain top is exactly the example I was thinking of. It looks like I am thinking the grads will make more of a "line" than it acutally does. Your shot blends in nicely. I am sure it takes practice to make it work but I can see where it would be useful. Thanks for your insight.

http://flickr.com …s/simplygeeky/2​224766386/

Tareq wrote in post #5098905
Get 3-stop GND Hard Edge for the Sky and 2-stop soft GND for the foreground, i am sure you will be fine and doing alot
0.9 Hard and 0.6 soft are the most popular choice, i got P-series Hitech GND from 0.3 up to 1.2 all soft, i broke 1.2 in Scotland, but when i got back i ordered 4x5 Hitech GND 1.2 soft and hard and 0.9 soft, i may add few more later.

Are there any differences using a soft GND on a crop body vs a FF? It would seem to me that since the image size is smaller, you'd want a faster transition between the clear and darkened areas. Does this make sense?

Are there soft GND filters for crop bodies?

E.

silverhalide wrote in post #5105424
Are there any differences using a soft GND on a crop body vs a FF? It would seem to me that since the image size is smaller, you'd want a faster transition between the clear and darkened areas. Does this make sense?

Are there soft GND filters for crop bodies?

E.

it is not like that, it depends on the focal length.
you can use P-series GND for focal length say 24mm and above, but if you go below 24mm then you will see some vignetting, then you should use Z-pro or ultrawide GND filters [4x4 or 4x5] to avoid vignetting, doesn't matter you use those filters on crop or FF because you know that 10mm on crop body is equivalent 16mm on FF, so you can say that you will find differences between crop vs FF, but it may help sometimes as if you use 16-35 on FF then it is ultra wide, but if you use 16-35 then it will be wide or very close to ultrawide but you know you should use same equivalent focal length to compare between bodies.
I hope i did explain it clearly.

I have a soft .9 GND and love it. I take it everywhere. Usually I just hold it in front of the lens because when I mount the holder, you can see it when zoomed out to 17mm.

Hangbot wrote in post #5113871
I have a soft .9 GND and love it. I take it everywhere. Usually I just hold it in front of the lens because when I mount the holder, you can see it when zoomed out to 17mm.

Yes, you are right, but do you use 17mm on a full frame? and do you use P-series holder? If you use Z-pro holder than i think you can't see or very hardly you will see the holder at 17mm, i tried it on 10-22 at 10mm on 30D and i don't see that holder [only very very tiny vignetting corners appears few times due to my wrong screwing maybe].

I'm using the P-series holder on a 30D and a 40D. With the 17-55 I can see the holder until around 20mm. But even with the vignetting from it, the benefits of the GND outweighs it when you need it

Tareq wrote in post #5105707
it is not like that, it depends on the focal length.
you can use P-series GND for focal length say 24mm and above, but if you go below 24mm then you will see some vignetting, then you should use Z-pro or ultrawide GND filters [4x4 or 4x5] to avoid vignetting, doesn't matter you use those filters on crop or FF because you know that 10mm on crop body is equivalent 16mm on FF, so you can say that you will find differences between crop vs FF, but it may help sometimes as if you use 16-35 on FF then it is ultra wide, but if you use 16-35 then it will be wide or very close to ultrawide but you know you should use same equivalent focal length to compare between bodies.
I hope i did explain it clearly.

You explained equivalent focal lengths well enough, but that wasn't really what I was getting at. I'm not concerned about the vignetting, but rather how soft the transition is, and whether that varies with body type. Let me try again...

A soft GND filter transitions from clear to dark over the distance of (for the sake of argument, let say) 25 mm. For some arbitrary lens, with a diameter of 77 mm, on a full frame body, that means the bottom 1/3 of the image hitting the sensor is clear, 1/3 has some degree of darkening, and 1/3 is solidly darkened.

On a crop body, where only the center part of the image circle is used, does the 25mm of transition represent a more gradual transition in the image? Since we're only using the center part, perhaps this would be 1/4 of the image clear, 1/2 in transition, 1/4 dark.

Perhaps the attached diagram would help. Here you see that on a crop sensor, almost the entire image is taken up by the transition area.

So, my question comes down to: With a crop body, do you need a GND with a sharper transition than when using a FF body?

E.

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silverhalide wrote in post #5116066
You explained equivalent focal lengths well enough, but that wasn't really what I was getting at. I'm not concerned about the vignetting, but rather how soft the transition is, and whether that varies with body type. Let me try again...

A soft GND filter transitions from clear to dark over the distance of (for the sake of argument, let say) 25 mm. For some arbitrary lens, with a diameter of 77 mm, on a full frame body, that means the bottom 1/3 of the image hitting the sensor is clear, 1/3 has some degree of darkening, and 1/3 is solidly darkened.

On a crop body, where only the center part of the image circle is used, does the 25mm of transition represent a more gradual transition in the image? Since we're only using the center part, perhaps this would be 1/4 of the image clear, 1/2 in transition, 1/4 dark.

Perhaps the attached diagram would help. Here you see that on a crop sensor, almost the entire image is taken up by the transition area.

So, my question comes down to: With a crop body, do you need a GND with a sharper transition than when using a FF body?

E.

I see, i have to check my Geneva Paris photos as i was using only 30D and 350D with GND filters and CPL sometimes.
And i have Scotland photos where i was using 5D with same GND [P-series].

silverhalide wrote in post #5116066
So, my question comes down to: With a crop body, do you need a GND with a sharper transition than when using a FF body?

No... I prefer to look at it a different way, by changing the field (angle) of view. In other words, you just need the same equivalent field of view on the crop camera.

Just as with other things, that means getting an equivalent lens.

So a 24mm lens on a full-frame camera... means you need a 15mm lens on a crop (1.6) body camera. Thus, the angle of view will be the same and thus, the transition size will appear the same.

At least, I think this is all true. The math works out on the 10-22 vs. the 16-35, after all. At 10/16, the angle of view is virtually identical (it's off by about half a degree).

I use a 3-stop soft for most of my landscape work. I find this to be generally pretty good at opening up the ground enough while providing a proper or slightly dramatic sky.

Check out the Singh-ray stuff. http://singh-ray.com

They also make reverse ND grads for sunsets. Very cool stuff, very high quality.

I thought I read on here to use the middle slot on the holder but while shooting recently, I got a reflection on the top corners of the filter so I moved it to the slot nearest the lens. Which slot do all of you normally use?

Nic