I am an amateur photographer, I have Nikon D7500 and three lenses, which are: 1) 10-20mm wide-angle lens (f4.5-5.6) - filter attachment size: 72mm 2) 35mm f1.8 - filter attachment size: 52mm 3) 18-140mm (f3.5-5.6) - filter attachment size: 67mm and as you can see here, all lens has different filter attachment size, and cannot buy 3 ND filters, please help me to select which one to buy for so I can take long-exposures shots at day-time for landscape, seascape, and cityscape. Thanks
I'm going to provide a second answer to this question (there's nothing wrong in providing two answers).
Somehow, the "landscape", "seascape", "cityscape" suggests me that you want to take wide-angle shots. So certainly you don't want the filter for 35mm f/1.8 lens. I would based on the "-scape" pictures suggest 72mm filter for the wide-angle zoom lens.
As a bonus, the wide-angle zoom lens takes the largest filter, so if you later need the filter on other lenses, you can purchase step-up rings as needed.
There are basically two ways to share filters between lenses with different thread sizes.
- You can buy screw on filters that fit the larger lens and use a step up ring to attach those filters to the smaller lens.
- You can use a system of filter holders that use adapter rings to attach to lenses with various filter thread sizes. You then use filters, many of them square, that fit the holder. The Cokin P-series system has rings available to fit lenses with thread sizes between 48mm and 82mm.
If you are considering any work with graduated Neutral Density filters then the advantages of the second approach should be obvious: you can slide the graduated filter up or down in the holder to change the exact placement of the transition with regard to the scene within the field of view.
An example of the first method.
And an example of the second.
Buy the largest one you need, and a couple step up rings to make it fit the other lenses. The caveat is that, especially for the smallest, you probably won't be able to use a lens hood and the filter at the same time. If that's a problem, start saving to own several ND filters eventually.
If long exposure is your aim (i.e. you are sure to work off a tripod) consider one of the 4×4" (10×10 cm) square filters with holders + a set of adapter rings.
Such kit will be extremely unwieldy & entirely unsuited for handheld shooting, but it is the best practice in landscape photography.
If a square filter set does not match your needs / means just buy 72mm ND and a bunch of step down rings (again, the enterprising Chinamen on the well known auction site are your friends).
There's a different option: take a burst of short-exposure pictures, and combine them on the computer to create the long exposure.
This is the cheap approach: you can save money by not purchasing filters
Jump to 2:44 for discussion about ND filters. By not using ND filters but instead combining multiple short exposures in post-processing, you get less noise than with ND filters.
If using Windows, you probably want to use Photoshop. However, if on Linux, Photoshop is not available, so you need to resort to command line:
align_image_stack -a OUT *.JPG hugin_stacker --output=mean --mode=mean OUT*.tif
This creates a file named
mean.tif that contains the aligned and stacked images.
If you want to be really cheap, you can skip purchasing tripod too and just try to keep the camera steady when taking the burst of photos. The
align_image_stack utility corrects for any camera movement between images, but obviously it cannot be perfect so tripod would be good.