GND Filters...help me.

[NewHampshire]

Ok, I am looking to pick up some GND filters for landscaping. I think I am going to go with the Cokin P series mount instead of the circular screw on mounts, but am still up in the air right now. But the biggest issue at ahnd right now is I need to make a decision. I have a few other high cost items I need right now (new tripod and flash unit) so I won't be able to drop a lot of huge cash down on filters, which means that I can only really pick up one or two filters to start with. I could get the whole spectrum if I go with the Cokin brand, but I have heard that the Cokin ND filters are not so neutral sometimes (i.e. people get purple skies.) It sucks because they list for only $18 each, but if I am going to do it, I should do it right I figure. So that leaves me with more pricier options, and thus the need to pick only one or two to start with before building up the collection.

SO.......if you could only have one or two factors and densities (hard or soft edge) which would you choose? .3 or .6 Soft? .3 or .6 Hard? one each soft and hard .3?

Brian

 

[Mark Schaefer]

The P holder is a good choice, as it will give you more flexibility in positioning the point of gradation. The Cokin A filters are not large enough for many wide lenses. As you mention Cokin filters are not truly neutral gray. Tiffen, Singh-Ray, Lee, and Hi-Tech filters are more neutral. They are also sufficiently long to allow positioning the gradation higher or lower in the frame. The screw in filters are the least flexible as they force the gradation through the center.

With landscapes and nature subjects (or any subject for that matter) I have never had an absolute need for a hard edge split ND. Even with a flat horizon the sky is not a uniform shade, so the soft edge will not look unnatural. If you need a really hard edge, you might be able to position the far edge of the filter's dark side where you need it. So I would recommend soft edge only. The soft edge will appear the more natural in most applications.

Generally when you need a split ND you need more rather than less gradation, so if you only buy one - get the 0.6 (2 stop). If you can afford two, buy a 0.6 and 0.3 (1 stop), and you can use them together if you need a 0.9 (3 stop).

 

[NewHampshire]

Generally when you need a split ND you need more rather than less gradation, so if you only buy one - get the 0.6 (2 stop). If you can afford two, buy a 0.6 and 0.3 (1 stop), and you can use them together if you need a 0.9 (3 stop).

This is what is suspected, but wanted to confirm. Thank you. Looking at the B+H website the Hitech's go for about $62.50 each, so $120 for 2 filters is a bit high, but reasonable for the quality I will be getting (I hear the Hitechs are the "middle of the road" in quality.)

Man, this darn photog addiction sure is expensive!!!

Brian

 

[kmorgan]

This is what is suspected, but wanted to confirm. Thank you. Looking at the B+H website the Hitech's go for about $62.50 each, so $120 for 2 filters is a bit high, but reasonable for the quality I will be getting (I hear the Hitechs are the "middle of the road" in quality.)

Man, this darn photog addiction sure is expensive!!!

Brian

Hey NewHampshire,
I recently got the Cokin P holders for my Rebel XT lenses from B&H. I also bought the HiTech filters to avoid the color cast associated with the Cokin filters. Be careful ordering! You have to read the filter descriptions carefully, you are looking at the HiTech combination filters. They are GND with color tint (e.g. 81B, 81EF, etc.). The plain untinted GND filters are $39.95 each.

Regards,
Kevin

 

[NewHampshire]

Hey NewHampshire,
I recently got the Cokin P holders for my Rebel XT lenses from B&H. I also bought the HiTech filters to avoid the color cast associated with the Cokin filters. Be careful ordering! You have to read the filter descriptions carefully, you are looking at the HiTech combination filters. They are GND with color tint (e.g. 81B, 81EF, etc.). The plain untinted GND filters are $39.95 each.

Regards,
Kevin

Ahhhhh, wait I see whats wrong here!

Yes I knew there was the combination GNDs and regular GNDs. Thats what I watched out for. The price discrepancy I see is baecause I was looking at 4x5 filters, not the P series size filters! The 4x5 are $83 for combo, $62 for regular. The P series, however, are $60 for $40. Big difference there. Thanks for the heads up!

So this is actually pretty good news. 2 filters will only be $80, so I will get myself a .3 and .6 soft, and I may just buy doubles of both in case I run into a situation where I want the same factor to cover both top and bottom (like perhaps sky and snow) or as a back up in case one scratches.

Brian

 

[darren]

All good advice so far. make sure when you get the P holder that you also get the ring adapters for the lenses that you have. If one lens is a 52mm and you have another lens that is 77mm then you need a ring adapter for each one. I am refering to the size of the front of the lens (width), not the focal length of the lens. You might already know this, but I just wanted to throw it out there in case you didn't. The ring adapters are cheap.

-darren

 

[NewHampshire]

Yes, Darren, I know about the ring adapters. Thank you. I think I am also going to get the add on P series "Wide Angle" holder since My Pentax prime is a 24mm. The "Wide Angle" supposedly has only one slot which eliminates vignetting from the 3 slot standard P series holder when using side angle lenses.

Brian

 

[forestgnome]

Great thread! It's time for me to start using ND on landscapes as well.

My primary lens is a Sigma 24-70mm EX Aspherical, filter size of 82mm, on a Digital Rebel 300D. So, I'll go with a set of soft-edged, .3 and .6 NDs. I like Tiffen, and I need an 82mm adaptor ring.

Does that sound right? Thanks

 

[darren]

My primary lens is a Sigma 24-70mm EX Aspherical, filter size of 82mm, on a Digital Rebel 300D. So, I'll go with a set of soft-edged, .3 and .6 NDs. I like Tiffen, and I need an 82mm adaptor ring.

Does that sound right? Thanks

Yes, and don't forget the Cokin P size filter holder.

- darren

 

[darren]

A couple other things that have not been brought up that shoud be mentioned. When using a GND filter you want to line up the filter with the light to dark transition in your shot. When doing this, the proper way to do it is to stop the lens down using Depth Of Field (DOF) preview, and then adjusting the filter. Lets say you are using a f 5.6 lens. When you look through the view finder the lens will be wide open at f 5.6. It provides the lightest view and allows you to see what you are shooting. Then you set up the camera to shoot at f 16 for greater DOF (everything in focus from the foreground to the background). When you look through the view finder, the lens will still be wide open at f5.6. When you press the shutter button, the lens closes down to a small f16 hole, the mirror flips up (your view finder goes black), the sensor or film is exposed, the mirrow flips back down, and the lens opens back up to f 5.6 and you see the bright scene in the view finder again. When looking through the view finder, if you press the DOF preview button the lens will stop down to the set aperture and the view finder will 1) get darker and 2) you will see the scene in focus as it will be shot.

It will take a while getting used to the dark view finder, but it will allow you to position the GND filter properly where you want it. If you are shooting at f 16 and you position the GND filter while you are looking through the lens at f 5.6 then you will not get the filter in the proper location. You can come close, but it will not be ideal. So always use DOF preview when aligning your GND filters. DOF preview used to be an extra that you paid more for on SLRs. Most cameras now come with it standard. It is also very useful in macro work.

One other thing to mention about using GND filters is how your lens focuses. If your lens has internal focus, then the front element of the lens (where the filter attaches) does not rotate when the lens focuses. Cheaper lenses will rotate the front element when focusing. It is a royal pain to use a GND filter on a rotating front element. It is possible, but it is a royal pain. it is something to think about when you are purchasing a lens. If you plan on doing a lot of landscape photography then get lenes with internal focus.

- darren

 

[NewHampshire]

Some more great tips. Thanks Darren.

Brian

P.S. Yes, I am still getting used to the DOF preview button