Faster 90mm lens?

[Dan V]

Recently I was literally between a rock and a hard place when photographying a waterfall. I was barely able to make the photo. Not only was my 90 mm f/8 lens a bit too long for my close proximity to the falls (moving wasn't an option although a 75mm lens might have been just the ticket), but I was more disappointed in how relatively dark the gg appeared when trying to focus - and that's with a new Satin Snow glass and a 4x loupe.

I' m considering replacing this lens with a faster lens of the same focal length if that would significantly brighten the image on the gg. Newbie question for you seasoned LFers: would the same length lens in an f/5.6 or 4.5 give me a noticeably brighter view for focusing?

If so, I'll have a beautiful Fujinon lens for sale very soon.

[Armin Seeholzer]

Hi Dan

Yes it is much brighter and easier to focus with a f 4.5 then a f 8. I have booths but the f 8 is only still in may hands because its the only LF lens with a selftimer!

[Mark Sawyer]

While it doesn't help with composing the image, I've found a good way to focus in low light conditions is to put a little flashlight or two in the subject area while focusing. Not always possible, especially when photographing waterfalls, but if you can do it, it works very well. It doesn't seem to help to shine one on the ground glass under the dark cloth to see the image better...

[Eric Leppanen]

Dan,

Yes, going from f/8 to f/4.5 will make a significant difference, not just when composing in shadow areas but also sunrise shots where you want everything focused and ready to go before the sun pops over the horizon. IMHO the best option here for landscape/field use is the SS80XL, an f/4.5 lens with good coverage which weighs only 271 grams (0.6 pounds). You may need a center filter with this lens, though, especially if you shoot chrome film.

[Matthew Cromer]

Instead of $1200 for an SS XL which will help some, why not spend $250 for a wide-angle fresnel and extra back which will help even more by illuminating the GG evenly?

[Donald Hutton]

Satin Snow ground glass is very "smooth" to look at. However, when I did a test with an identical lens, it was at least two full stops less bright than my Ebony which has a built in fresnel. It's a good product for the price, but it's not a solution to everything.

[Gem Singer]

Hi Dan,

Certainly, a 90 wide angle lens with a larger maximum aperature will be brighter for composing and focusing on the ground glass. However, most of those faster lenses are also larger, heavier weight, take larger sized screw-in filters, and are quite a bit more expensive. That's the trade-off. Only you can decide if it's worth while to purchase a faster wide angle lens.

[Leonard Evens]

I have no trouble focusing my f/6.8 90 mm Grandagon-N with my Maxwell screen in dim light. If you are going to make an investment, it would seem more sensible to get such a screen.

[Dan V]

Thanks to all for your helpful suggestions. I have decided to e-retire my f/8 and replace it with a faster lens.

[Brad Rippe]

Dan, I use a Nikkor 90mm f/8 sw and love it. In dark situations it does take a bit more time for our eyes to adjust to a lower light level under the darkcloth. An f/5.6 will be brighter, but before selling your lens, you might rent or borrow one and make sure. Be sure to use a loupe! That will help a lot. I've heard that John Sexton sometimes uses a laser pointer for very dark situations. I've never used a laser but it seems you'd need an extra set of hands, or somehow clip it to your tripod.

[David Parker]

Hi Dan,

You have run into one of the difficult situations that yes a faster lens is going to make a big difference, and I would suggest a fresnel as well, as Don mentioned, our glass is very smooth and allows a better distribution of light, but is not the solution to every single situation that can occur, I would expect any light measurement to be 1.5 to 2 stops brighter by adding the fresnel to any type of glass screen, you might try the less expensive route and add a fresnel first, but my suggestion, would to be get the faster lens, as f/8 is a slower lens and does not let as much light in as the faster lenses.

Good luck and good shooting.

Dave Parker
Satin Snow Ground Glass