Comparison

i3DSteroid vs HDRI Prep

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

i3DSteroid

View and create stereoscopic images and videos on your iPhone, iPad, or iPod touch. Supports various input formats and display methods, including smart glasses. Offers tools for image adjustment, saving, and sharing.

Highlights
  • Auto-align L/R images
  • Supports SBS, MPO, and spatial photos
  • Multiple display methods (SBS, Anaglyph, Wiggle)
  • Smart glasses support (XREAL Air2, VITURE One)
  • Take L/R pictures with internal camera
  • Adjust L/R image positions and rotation
  • Save and slideshow displayed images
Features
Read full description

[i3DSteroid] is a stereoscopic Universal application for iPhone/iPad/iPod touch. - Auto-alignment L/R images - Input file : L/R independent,SBS,MPO,spatial photos - Over 1000 images WEB Galleries access - Display method : SBS,Mirror,2D,Anaglyph,wiggle,etc - Support for smart glasses such as XREAL Air2/VITURE One - Save displayed image. - Slide Show - Take L/R pictures with the internal camera. - Adjust L/R image positions and rotation error. - Post the image to Twitter/Facebook. - Image crop. - Support Flucard. - etc

About

HDRI Prep

This utility helps visual effects professionals create HDRI bracketing sets for RICOH THETA 360 cameras. It allows for quick definition, organization, and reuse of bracket settings, streamlining on-set workflows for HDR photography.

Highlights
  • Define custom bracket sets (3-19 photos, 1-3 stops apart)
  • Set Aperture, ISO, and Color Temperature for all photos at once
  • Define Center Shutter Speed to extend exposures
  • Name, organize, and reorder brackets by show
  • Duplicate and move bracket sets between shows
  • View photos read directly from the camera
  • Quickly adjust camera speaker volume and auto-sleep time
Features
Read full description

Build a library of HDRI exposure brackets for your RICOH THETA V, Z1 or X, and fire them off on set in seconds. The THETA can shoot multi-exposure brackets, but setting them up in the official app is slow, and you can't save them to reuse later. HDRI Prep fixes that. Set up a bracket once, name it, file it under your show, and call it up whenever the lighting calls for it. BUILD BRACKETS THE WAY YOU THINK • Choose 3 to 19 photos, 1 to 3 stops apart. No need to set each exposure by hand. • Pick a center shutter speed, and the bracket spreads evenly above and below it. • Set aperture, ISO and color temperature for the whole bracket at once. Choices are limited to what your camera can actually do. ORGANIZED FOR PRODUCTION • Name brackets, group them by show, drag to reorder, and copy or move them between shows. • Each bracket is tinted by its color temperature, so tungsten and daylight setups stand out at a glance. ON SET • Live View, flat or as a 360° view you can drag around, to check the frame before you shoot. • A shot counter and timer while the bracket runs, and Cancel if you need to stop. • View the photos from that bracket the moment it finishes. • Browse the camera's photos, inspect them full screen or in 360°, share them to Photos, Files or AirDrop, or delete them from the camera. • Find nearby THETAs and join their Wi-Fi from the app. Cameras you've used are remembered. • Adjust the camera's shutter volume and sleep delay. TRY IT WITHOUT A CAMERA Demo Mode loads sample 360° brackets so you can explore every feature before you plug in a THETA. Works on iPhone, iPad and iPhone Duo, and includes a built-in Manual. GOOD TO KNOW • HDRI Prep connects over the camera's own Wi-Fi (the camera's access-point mode). • Shutter volume and sleep delay are saved to the camera itself, so they stay set even when HDRI Prep isn't running. • HDRI Prep focuses on bracketing. It isn't a replacement for the official THETA app, which works well alongside it. Built by a VFX artist for VFX artists. If "HDRI" and "THETA" mean something to you, this was made for you. HDRI Prep is not affiliated with or endorsed by RICOH. RICOH THETA is a trademark of Ricoh Company, Ltd. Site and Privacy Policy: https://squirrelfx.llc/hdri-prep.html

Screenshots

i3DSteroid4 screens
HDRI Prep4 screens

Verdict

The call

The clearest difference is price: i3DSteroid at $2.99 against HDRI Prep's $9.99. i3DSteroid also leads on update cadence (every 3 weeks vs every 9 months) and iOS requirement (15.0 vs 17.0). HDRI Prep's advantage is review sentiment (100% vs 76%). On ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

i3DSteroid costs $2.99 and HDRI Prep $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

i3DSteroid ships an update every 3 weeks, HDRI Prep every 9 months. The most recent releases landed on November 1, 2026 and October 30, 2026 respectively.

Scorecard5 real differences · 5 level
i3DSteroid versus HDRI Prep: the parameters behind the verdict, then further details
Parameteri3DSteroidHDRI Prep
Price$2.99 — better$9.99
Rating4.4 (38 ratings) — better—
Positive reviews75.8% of reviews100.0% of reviews — better
Number of ratings38 — better—
Update frequencyEvery 3 weeks — betterEvery 9 months
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better17.0
Further details — not scored
Size5 MB11 MB
Age rating4+4+
DeveloperSpmakerSquirrel FX LLC

Customer experience

i3DSteroid

All ratings38 ratings
Positive84.2%
Neutral10.5%
Negative5.3%
Written reviews66 reviews
Positive75.8%
Neutral10.6%
Negative13.6%

HDRI Prep

Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

i3DSteroid

No in-app purchases

None

HDRI Prep

No in-app purchases

Questions

Is i3DSteroid free?
i3DSteroid costs $2.99, with no in-app purchases.
Is HDRI Prep free?
HDRI Prep costs $9.99, with no in-app purchases.
Do i3DSteroid or HDRI Prep have ads?
Neither i3DSteroid nor HDRI Prep shows ads.
Which is updated more often, i3DSteroid or HDRI Prep?
i3DSteroid ships an update every 3 weeks, and HDRI Prep every 9 months. Most recently, i3DSteroid was updated on November 1, 2026 and HDRI Prep on October 30, 2026.

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