JTW Astronomy - Aalsmeerderweg 103

Modified Nikon D850. Yet to use for astrophotography, but camera appears in working condition. Great service, communication and price. Fast service from UK to Netherlands.

I had my Nikon D750 modified and the results are very good. Mark kept me up to date throughout the process and wouldn’t hesitate to use his expertise in the future.

Sent my 6D to JTW for a filter replacement. I am very satisfied with the results. The camera is sharper in daylight picture and Ha pops out at night. The procedure was quick and Mark communicated nicely and often.

I sent my Sony a7 III camera to JTW Astronomy in May for astro modification and received it back a few weeks later. The astro-modification significantly improved the sensitivity of the camera, but I noticed that the stars at the edges of the images were elongated / out of focus when used with my Sony 24mm f/1.4 GM lens (my Rokinon 135mm f/2 lens was fine), so Mark offered to take another look at the camera and tweak the sensor position, and kindly covered the shipping for this. I also sent two of my lenses for testing. It took a while to get the camera and lenses back, but I understand they were closed for a couple of weeks due to sickness. When I tested my Sony 24mm GM lens after getting the camera back, unfortunately I still noticed elongated stars all around the edges (even when stepped down to f/2.8), meaning only the center of images would be usable with this lens. I tested the lens on my non-modified a7R III and the stars are fine with that camera, so this is just an issue since having the a7 III astro-modified. According to Mark this may be due to the mod filter being slightly thinner than the one it replaced, and the design of this particular lens. While I love how sensitive the camera is for astrophotography, I'm disappointed I can't really use my Sony 24mm GM lens for wide-field astrophotography with my modified camera body. Please be aware if you have this same lens, you may also experience a similar issue after having your camera astro-modified.

Actually I don't know what happend to them, everyone says that they are good but the order i did more than 1 month ago of a astro sony a7 is still missing, hope to get emailed soon :) UPDADTE: Just got emailed by Mark and updated on the status of the camera :) i know this is a tough period for everyone and that's why i'm giving back 5 stars :) p.s. If this work goes well i'll be able to buy an astro A7 iii :P

For my mount I ordered a new RA worm as a replacement of my paramount ME worm, price was correct for a precision worm and bearing to replace my old worn out one. Turns out the worm was fine polished too and now my paramount tracks better with even with less periodic error than new. So not only cameras but also precision mechanics.

I bought a H alpha modified Nikon D5600 from JTW. There were a few delays mainly due to covid and supplier delays but Mark kept me in the loop, his communication was great throughout. As for the camera, it works great and I'm very impressed with the results! I have some sample images on my Instagram @dom_reardon_photo

Unfortunately I don't have good feedback. Long story short, camera modification took 2-3 months with VERY POOR communication before I eventually had to cancel the order. Afterwards, refund was promised but till now (for last 2 months) I'm struggling to get my money back. Again, very poor responses. Overall, its more than 5 months now. I do understand the difficult times on businesses due to current situation, but it does not stop being transparent and upfront with clients. I thought many times before posting this review, but I finally decided to go ahead to stop others end up in the same situation as I am. I would think twice before going ahead with JTW Astronomy for camera modifications. # Update January 2022# Still waiting for the refund. Mark contacted me 5-6 months ago and agreed for partial payments every months and to settle over a period of time but not actioned on it. As usual communication is very poor as well. I do appreciate potential difficulties due to pandemic. But I would have appreciated monthly down payments as agreed even if they were small to drive this to a closure.