I've used a similar star focus mechanism before, but for lenses that had lens filters 85mm and under. I used this on my 95mm lens filter. After putting it on, I started to focus onto a bright and was expecting the cross lines to appear and they didn't until I was just about in focus. That's why it was a suprise. It crept up me but when the cross appeared, it was dead on accurate! Wonderful results. Well worth the price!
Arrived no problem, only realised it from USA when during shipping tracking saying leaving USA city etc (so I thought maybe hassle returning etc / not worth cost) etc.
1st time I tried it moonless clear sky,pitch dark night, zero light pollution, north Scotland, sky full of stars but no matter what star I tried it was useless, too faint on live view. Sony a7iii, samyang 24 f2.8, Sony 70-200 f4 even my sigma 14mm f1.4 DN. No X showing on live view up so I consigned this to my junk drawer.
Then I got the 60 day review email & tried it again on my old Sony a7 full spectrum modded, samyang 135mm f2, 1 day after full harvest moon with Jupiter (close by) as subject. Live view zoomed in & Jupiter showed up fine with usable X in live view.
So it works at 135mm on Jupiter but not my wide lenses. For wide lenses I use my screw on star eight filter (which works perfectly on southern hemisphere : capetown) on my 24mm f2.8.
I’ll keep trying this mask, some nights it’l work & others not so. But Mega bright objects req.
excellent bahtinov mask, the fine patten works on my 50mm, 135mm lenses and my refractor scope perfectly with a dslr or dedicated astro camera, it even worked on my 30mm guide scope. Very satisfied with this mask and would highly recommend.
This is a perfect tool and works very nicely with my Canon camera. I am highly satisfied with the results.
Works great on DSLR telephoto lenses. Definitely recommended.
This mask works good as intended. No complaints there. The problem I have is that it came to me dinged up, thin metal ring has dents, and there is some sort of adhesive smeared all over the back side of the mask. I tried to clean it but it won’t come off. Poor quality control. I emailed Johannes Scientific about this and never heard back. It functions well but looked used and abused. It did come sealed so it’s a manufacturer’s issue. Still, Johannes should pay closer attention to what they sell.
This Bahtinov mask really works with a DSLR paired with a telephoto lens. I have tested it with my Nikon D5500 and the Nikkor AF-S 300mm F/4 ED-IF with and without the 1.4x teleconverter. The refraction spikes are clearly visible in magnified "Live View" and correct focus can be achieved with no issues. This is an improved design with very thin pattern lines.
Laser cut and sharp, gives a nice easy to see diffraction pattern, and the adjustable nature makes it a breeze on multiple OTA's. A+
I am doing astrophotography with my Canon L series lenses and focusing can be a problem when not using a DSLR or Mirrorless. I have a large mask for use with my 400mm f4 DO which works fine but with the 100-400mm zoom or my 85 f1.8 the grating was overly wide and didn't work well. I got the JS mask for 80-120 and it is ideal for the shorter focal lengths. Very good quality and a tight diffraction grating.
The filter is well made, easy to use. It’s made getting that perfect focus for these night shots bloody easy now.
I used this for the partial eclipse in 2023, it worked perfectly! very secure, didn't have to readjust. 10/10 recommend!
Great tool for Astro focusing, bought for use with a Fuji lens and it is really effective.
Applying the Bahtinov to night photography, for me, is a new concept. Which is a good thing….I love to learn new concepts. The Bahtinov filter is well made, easy to pack in the backpack and easy to work with in low light conditions.
Very good, manufactured with precision. It meets my expectations!
Must be handled and stored with care.
This is the 2nd purchase of a Bahtinov mask I've made from Johannes Scientific. The reason was so I could keep one mask with each of my imaging rigs, one at the objective lens of a 90mm refractor and another mounted to a threaded-on filter adapter for a Canon DSLR lens. The masks simply work wonderfully in both use cases. I highly recommend, and I have recommended, these Johannes Scientific Bahtinov masks to friends and other folks in astronomy/astrophotography forums I frequent.
After some initial confusion about the pins that come apart for attachment to the lens, it worked like a charm. Finally a tool for wide angles with attached lens hoods. Side note if you need the pins to be a little longer i found that the screws for the Fotodiox Wonderpana Arc free 6.6" x 6.6" filter holder brackets fit these pins like a glove if you need some extra pin length for stability. Great product and customer service!
I often struggled getting sharp infinite focus. This Bohtimov mask was a game changer. I managed to get good sharp focus within a few seconds.
Allthough the interferring lines were not straight I was able to get good focus and sharp stars with this tool. Dont know why the lines werent straight, maybe the distance from the frontlens was problably to much.
Works a treat for improving focus, particularly for longer focal lengths. My only complaint would be that the three adjuster layout does not work well for "petaled" lens hoods.
Seriously, I am sure it is a great product, but 45 nights in a row since purchase has prevented a trial. Maybe you could enclose clear skies in the package.
Works a little better than a coarse Bahtinov Mask for wide angle lenses, but does not resolve all 3 lines. However dots where those lines would converge do come through and are easier to focus with than a bright star alone. At focal lengths above 100mm, the 3 lines come through well and it's very easy to focus.
Really easy to get sharp stars. I use the 80-120 and will need to get also the 60-90 for my new camera. I recommend this product. Well made, fast shipping.
The Problem: Hard to get an accurate focus using my Zuiko 50 and 135mm lenses.
The Solution: A 60-90mm Bahtinov mask from Johannes Scientific.
The Story: I use some vintage Zuiko lenses and smaller refractor telescopes for my DSLR astrophotgraphy. I needed a mask with a fine grid that would produce a crisp diffraction pattern. The JS 60-90mm mask works perfectly. The pattern is crisp, well defined and performs well even when I can't sight a high magnitude star for focusing. The mask is a quality build, easily adjusted to fit a range of lens diameters and my smaller refractors. The JS Bahtinov mask has made getting a sharp focus much easier and enjoyable. Shipping was prompt and hassle-free. A win-win all around and I recommend the JS Bahnitov mask to others I know who do astrophotography.
These screws are just what I needed for my DIY Bahtinov masks. The parts screw together well and hold the mask in place. The only issue is the plastic tips are not tightly fitted to the screw and could fall out it you're not careful. A touch of glue to hold the soft tips onto the metal part should do the trick.
I've been struggling with astrophotography to get a sharp focus. I use a DSLRon a tripod or a DSLR with a telescope. Recently I got this Bahtinov mask and I've used it just with the DSLR. I plan to try it with the DSLR and telescope later. We just don't have that many clear sky nights.
My results on the first night were SO much better that I consider this a success. I used the mask as prescribed and got good results.
If I were to suggest an improvement to the mask, it would be to super-glue the little black tips to the fasteners. Otherwise they fall off and are hard to retrieve.