Pro-slide: New product announcement

By the pure accident (to be completely honest I was just aimlessly browsing eBay 😀) I came across some strangely shaped GEPE slide mounts. They have 37.5 x 37.5 mm opening in the standard 50x50 form-factor and come with anti-newton glass covers.  The built-in flash popped up in my head: those mounts would be perfect for mounting the full frame slide if I ever want to project the slide with the rebate area and sprocket holes. The more utilitarian use for these mounts would be to use them to perfectly tune a scanning rig so exact  film camera 24x36 mm  dimensions would be available for framing.   Typical paper or plastic slide mounts have 23x35 mm opening to allow film frames  from the different cameras be mounted even if some cameras have the film gate of slightly varying height and width. Not only photographers have to be very precise while framing the view during the shoot,  they also will struggle with digitizing the mounted transparencies as the majority of the mounts are rather thick up to the edge and this inevitably causes  edges of the frame to be poorly illuminated because of non-zero thickness of the mount. GEPE mounts with the metal mask are the best, but still whatever is widely available have the 23x35 opening. 

Anyway, imagine having a mounted pro-slide which has the opening big enough to have 24x36 mm area precisely delineated,  plus extra marks showing 23x35 and 21x33 mm areas. Before you start scanning 35 mm mounted slides, you would pop such a pro-slide in your slide holder and carefully move the camera to have either 24x36 or 23x35 mm area in the center of your viewfinder knowing exactly what your camera can see. The extremely uniform dot pattern with extremely high edge contrast would help you with the precise focusing and provide you with visual cue as to the uniformity of your backing light. Have I wetted your appetite?

Good! Now such a thing is readily available to our community. Introducing VLADS TEST TARGET FOR SLIDES (name is yet to be finalized). 

And here is how this test target looks like next to regular slides shot with a film camera in that same mount.

Below are the exact  measurements of the elements of the Pro-slide 

Here is how pro-slide is seen by camera Canon EOS R with Sigma 2.8/70 mm DG Macro Art lens. 

1. Camera is too far away from the holder:

2. Camera is almost , but not completely aligned:

Here is crop out:

Similarly designed 35 mm film strips are also available for immediate purchase. Actual item picture will be available tomorrow.  

Here is how the targets are produced. They are made on high resolution sheet photo film by exposing it to the direct He-Ne laser light at resolution of 3600 dpi on an industrial-strength equipment. No regular  lens or optics is involved so all the elements of the image are perfectly and precisely spaced and have very high edge contrast. So when I say that outer frame is 24x36 mm you may take good caliper and check that out. All lines are ideally straight so if the captured image shows some  barrel or pincushion  distortion, it can be safely attributed to the lens used for scanning. 

The slide thickness is 2 mm, the film is protected with anti-newton glass covers so it can take some abuse due to repeated use.  

Pro-slide and film strip are available at my Etsy store https://www.etsy.com/listing/1241581641/35-mm-transparency-for-digitizing

Note for folks outside USA: the slide to be shipped abroad needs rigid packaging which will trigger at least $14 international shipping fee. The only thing I can recommend is to stock up on my targets so the percentage you spend on shipping will be smaller as shipping fee is flat. 

Enjoy!